Bump version to 0.0.45

Document noqa workflows
Enable automatic noqa insertion (#256 )
2022-09-22 14:11:09 -04:00 · 2022-09-22 14:10:02 -04:00 · 2022-09-22 13:59:06 -04:00 · 2022-09-22 13:21:03 -04:00 · 2022-09-22 13:09:02 -04:00 · 2022-09-22 12:56:15 -04:00
27 changed files with 1491 additions and 622 deletions
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1801,7 +1801,7 @@ dependencies = [

 [[package]]
 name = "ruff"
-version = "0.0.40"
+version = "0.0.45"
 dependencies = [
 "anyhow",
 "bincode",
@@ -1846,7 +1846,7 @@ dependencies = [
 [[package]]
 name = "rustpython-ast"
 version = "0.1.0"
-source = "git+https://github.com/charliermarsh/RustPython.git?rev=7d21c6923a506e79cc041708d83cef925efd33f4#7d21c6923a506e79cc041708d83cef925efd33f4"
+source = "git+https://github.com/charliermarsh/RustPython.git?rev=966a80597d626a9a47eaec78471164422d341453#966a80597d626a9a47eaec78471164422d341453"
 dependencies = [
 "num-bigint",
 "rustpython-compiler-core",
@@ -1855,7 +1855,7 @@ dependencies = [
 [[package]]
 name = "rustpython-compiler-core"
 version = "0.1.2"
-source = "git+https://github.com/charliermarsh/RustPython.git?rev=7d21c6923a506e79cc041708d83cef925efd33f4#7d21c6923a506e79cc041708d83cef925efd33f4"
+source = "git+https://github.com/charliermarsh/RustPython.git?rev=966a80597d626a9a47eaec78471164422d341453#966a80597d626a9a47eaec78471164422d341453"
 dependencies = [
 "bincode",
 "bitflags",
@@ -1872,7 +1872,7 @@ dependencies = [
 [[package]]
 name = "rustpython-parser"
 version = "0.1.2"
-source = "git+https://github.com/charliermarsh/RustPython.git?rev=7d21c6923a506e79cc041708d83cef925efd33f4#7d21c6923a506e79cc041708d83cef925efd33f4"
+source = "git+https://github.com/charliermarsh/RustPython.git?rev=966a80597d626a9a47eaec78471164422d341453#966a80597d626a9a47eaec78471164422d341453"
 dependencies = [
 "ahash",
 "anyhow",
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "ruff"
-version = "0.0.40"
+version = "0.0.45"
 edition = "2021"

 [lib]
@@ -18,15 +18,15 @@ common-path = { version = "1.0.0" }
 dirs = { version = "4.0.0" }
 fern = { version = "0.6.1" }
 filetime = { version = "0.2.17" }
-glob = "0.3.0"
-itertools = "0.10.3"
+glob = { version = "0.3.0" }
+itertools = { version = "0.10.3" }
 log = { version = "0.4.17" }
 notify = { version = "4.0.17" }
 once_cell = { version = "1.13.1" }
 path-absolutize = { version = "3.0.13", features = ["once_cell_cache"] }
 rayon = { version = "1.5.3" }
 regex = { version = "1.6.0" }
-rustpython-parser = { features = ["lalrpop"], git = "https://github.com/charliermarsh/RustPython.git", rev = "7d21c6923a506e79cc041708d83cef925efd33f4" }
+rustpython-parser = { features = ["lalrpop"], git = "https://github.com/charliermarsh/RustPython.git", rev = "966a80597d626a9a47eaec78471164422d341453" }
 serde = { version = "1.0.143", features = ["derive"] }
 serde_json = { version = "1.0.83" }
 toml = { version = "0.5.9" }
--- a/README.md
+++ b/README.md
@@ -22,9 +22,7 @@ An extremely fast Python linter, written in Rust.
 - 📦 [ESLint](https://eslint.org/docs/latest/user-guide/command-line-interface#caching)-inspired cache support
 - 🔧 [ESLint](https://eslint.org/docs/latest/user-guide/command-line-interface#caching)-inspired `--fix` support
 - 👀 [TypeScript](https://www.typescriptlang.org/docs/handbook/configuring-watch.html)-inspired `--watch` support
-
-_ruff is a proof-of-concept and not yet intended for production use. It supports only a small subset
-of the Flake8 rules, and may crash on your codebase._
+- ⚖️ [Near-complete parity](#Parity-with-Flake8) with the built-in Flake8 rule set

 Read the [launch blog post](https://notes.crmarsh.com/python-tooling-could-be-much-much-faster).

@@ -88,7 +86,7 @@ ruff path/to/code/ --select F401 F403
 See `ruff --help` for more:

 ```shell
-ruff (v0.0.40)
+ruff (v0.0.45) 0.0.45
 An extremely fast Python linter.

 USAGE:
@@ -98,12 +96,20 @@ ARGS:
    <FILES>...

 OPTIONS:
-    -e, --exit-zero
-            Exit with status code "0", even upon detecting errors
+        --select <SELECT>...
+            List of error codes to enable
+        --extend-select <EXTEND_SELECT>...
+            Like --select, but adds additional error codes on top of the selected ones
+        --ignore <IGNORE>...
+            List of error codes to ignore
+        --extend-ignore <EXTEND_IGNORE>...
+            Like --ignore, but adds additional error codes on top of the ignored ones
        --exclude <EXCLUDE>...
            List of paths, used to exclude files and/or directories from checks
        --extend-exclude <EXTEND_EXCLUDE>...
            Like --exclude, but adds additional files and directories on top of the excluded ones
+    -e, --exit-zero
+            Exit with status code "0", even upon detecting errors
    -f, --fix
            Attempt to automatically fix lint errors
        --format <FORMAT>
@@ -111,14 +117,16 @@ OPTIONS:
            json]
    -h, --help
            Print help information
-        --ignore <IGNORE>...
-            List of error codes to ignore
    -n, --no-cache
            Disable cache reads
    -q, --quiet
            Disable all logging (but still exit with status code "1" upon detecting errors)
-        --select <SELECT>...
-            List of error codes to enable
+        --add-noqa
+            Enable automatic additions of noqa directives to failing lines
+        --show-files
+            See the files ruff will be run against with the current settings
+        --show-settings
+            See ruff's settings
    -v, --verbose
            Enable verbose logging
    -V, --version
@@ -127,6 +135,8 @@ OPTIONS:
            Run in watch mode by re-running whenever files change
 ```

+### Excluding files
+
 Exclusions are based on globs, and can be either:

 - Single-path patterns, like `.mypy_cache` (to exclude any directory named `.mypy_cache` in the
@@ -136,34 +146,71 @@ Exclusions are based on globs, and can be either:
  (to exclude any Python files in `directory`). Note that these paths are relative to the
  project root (e.g., the directory containing your `pyproject.toml`).

+### Ignoring errors
+
+To omit a lint check entirely, add it to the "ignore" list via `--ignore` or `--extend-ignore`,
+either  on the command-line or in your `project.toml` file.
+
+To ignore an error in-line, ruff uses a `noqa` system similar to [Flake8](https://flake8.pycqa.org/en/3.1.1/user/ignoring-errors.html).
+To ignore an individual error, add `# noqa: {code}` to the end of the line, like so:
+
+```python
+# Ignore F841.
+x = 1  # noqa: F841
+
+# Ignore E741 and F841.
+i = 1  # noqa: E741, F841
+
+# Ignore _all_ errors.
+x = 1  # noqa
+```
+
+Note that, for multi-line strings, the `noqa` directive should come at the end of the string, and
+will apply to the entire body, like so:
+
+```python
+"""Lorem ipsum dolor sit amet.
+
+Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
+"""  # noqa: E501
+```
+
+ruff supports several (experimental) workflows to aid in `noqa` management.
+
+First, ruff provides a special error code, `M001`, to enforce that your `noqa` directives are
+"valid", in that the errors they _say_ they ignore are actually being triggered on that line (and
+thus suppressed). **You can run `ruff /path/to/file.py --extend-select M001` to flag unused `noqa`
+directives.**
+
+Second, ruff can _automatically remove_ unused `noqa` directives via its autofix functionality.
+**You can run `ruff /path/to/file.py --extend-select M001 --fix` to automatically remove unused
+`noqa` directives.**
+
+Third, ruff can _automatically add_ `noqa` directives to all failing lines. This is useful when
+migrating a new codebase to ruff. **You can run `ruff /path/to/file.py --add-noqa` to automatically
+add `noqa` directives to all failing lines, with the appropriate error codes.**
+
 ### Compatibility with Black

-ruff is intended to be compatible with [Black](https://github.com/psf/black), and should be
-compatible out-of-the-box as long as the `line-length` setting is consistent between the two.
+ruff is compatible with [Black](https://github.com/psf/black) out-of-the-box, as long as
+the `line-length` setting is consistent between the two.

 As a project, ruff is designed to be used alongside Black and, as such, will defer implementing
-lint rules that are obviated by Black (e.g., stylistic rules).
+stylistic lint rules that are obviated by autoformatting.

 ### Parity with Flake8

-ruff's goal is to achieve feature-parity with Flake8 when used (1) without any plugins,
-(2) alongside Black, and (3) on Python 3 code. (Using Black obviates the need for many of Flake8's
-stylistic checks; limiting to Python 3 obviates the need for certain compatibility checks.)
+ruff's goal is to achieve feature-parity with Flake8 when used (1) without plugins, (2) alongside
+Black, and (3) on Python 3 code.

-Under those conditions, Flake8 implements about 60 rules, give or take. At time of writing, ruff
-implements 42 rules. (Note that these 42 rules likely cover a disproportionate share of errors:
-unused imports, undefined variables, etc.)
-
-The unimplemented rules are tracked in #170, and include:
-
- 14 rules related to string `.format` calls.
- 4 logical rules.
- 1 rule related to parsing.
+**Under those conditions, ruff implements 44 out of 60 rules.** (ruff is missing: 14 rules related
+to string `.format` calls, 1 rule related to docstring parsing, and 1 rule related to redefined
+variables.)

 Beyond rule-set parity, ruff suffers from the following limitations vis-à-vis Flake8:

-1. Flake8 supports a wider range of `noqa` patterns, such as per-file ignores defined in `.flake8`.
-2. Flake8 has a plugin architecture and supports writing custom lint rules.
+1. Flake8 has a plugin architecture and supports writing custom lint rules.
+2. Flake8 supports a wider range of `noqa` patterns, such as per-file ignores defined in `.flake8`.
 3. ruff does not yet support parenthesized context managers.

 ## Rules
@@ -182,11 +229,13 @@ Beyond rule-set parity, ruff suffers from the following limitations vis-à-vis F
 | E741 | AmbiguousVariableName | ambiguous variable name '...' |
 | E742 | AmbiguousClassName | ambiguous class name '...' |
 | E743 | AmbiguousFunctionName | ambiguous function name '...' |
-| E902 | IOError | No such file or directory: `...` |
+| E902 | IOError | ... |
 | E999 | SyntaxError | SyntaxError: ... |
 | F401 | UnusedImport | `...` imported but unused |
-| F403 | ImportStarUsage | `from ... import *` used; unable to detect undefined names |
+| F402 | ImportShadowedByLoopVar | import '...' from line 1 shadowed by loop variable |
+| F403 | ImportStarUsed | `from ... import *` used; unable to detect undefined names |
 | F404 | LateFutureImport | from __future__ imports must occur at the beginning of the file |
+| F405 | ImportStarUsage | '...' may be undefined, or defined from star imports: ... |
 | F406 | ImportStarNotPermitted | `from ... import *` only allowed at module level |
 | F407 | FutureFeatureNotDefined | future feature '...' is not defined |
 | F541 | FStringMissingPlaceholders | f-string without any placeholders |
@@ -212,6 +261,7 @@ Beyond rule-set parity, ruff suffers from the following limitations vis-à-vis F
 | F901 | RaiseNotImplemented | `raise NotImplemented` should be `raise NotImplementedError` |
 | R001 | UselessObjectInheritance | Class `...` inherits from object |
 | R002 | NoAssertEquals | `assertEquals` is deprecated, use `assertEqual` instead |
+| M001 | UnusedNOQA | Unused `noqa` directive |

 ## Development

@@ -247,29 +297,29 @@ Add this `pyproject.toml` to the CPython directory:
 ```toml
 [tool.ruff]
 line-length = 88
-exclude = [
-    "./resources/test/cpython/Lib/lib2to3/tests/data/bom.py",
-    "./resources/test/cpython/Lib/lib2to3/tests/data/crlf.py",
-    "./resources/test/cpython/Lib/lib2to3/tests/data/different_encoding.py",
-    "./resources/test/cpython/Lib/lib2to3/tests/data/false_encoding.py",
-    "./resources/test/cpython/Lib/lib2to3/tests/data/py2_test_grammar.py",
-    "./resources/test/cpython/Lib/test/bad_coding2.py",
-    "./resources/test/cpython/Lib/test/badsyntax_3131.py",
-    "./resources/test/cpython/Lib/test/badsyntax_pep3120.py",
-    "./resources/test/cpython/Lib/test/encoded_modules/module_iso_8859_1.py",
-    "./resources/test/cpython/Lib/test/encoded_modules/module_koi8_r.py",
-    "./resources/test/cpython/Lib/test/test_fstring.py",
-    "./resources/test/cpython/Lib/test/test_grammar.py",
-    "./resources/test/cpython/Lib/test/test_importlib/test_util.py",
-    "./resources/test/cpython/Lib/test/test_named_expressions.py",
-    "./resources/test/cpython/Lib/test/test_patma.py",
-    "./resources/test/cpython/Lib/test/test_source_encoding.py",
-    "./resources/test/cpython/Tools/c-analyzer/c_parser/parser/_delim.py",
-    "./resources/test/cpython/Tools/i18n/pygettext.py",
-    "./resources/test/cpython/Tools/test2to3/maintest.py",
-    "./resources/test/cpython/Tools/test2to3/setup.py",
-    "./resources/test/cpython/Tools/test2to3/test/test_foo.py",
-    "./resources/test/cpython/Tools/test2to3/test2to3/hello.py",
+extend-exclude = [
+    "Lib/lib2to3/tests/data/bom.py",
+    "Lib/lib2to3/tests/data/crlf.py",
+    "Lib/lib2to3/tests/data/different_encoding.py",
+    "Lib/lib2to3/tests/data/false_encoding.py",
+    "Lib/lib2to3/tests/data/py2_test_grammar.py",
+    "Lib/test/bad_coding2.py",
+    "Lib/test/badsyntax_3131.py",
+    "Lib/test/badsyntax_pep3120.py",
+    "Lib/test/encoded_modules/module_iso_8859_1.py",
+    "Lib/test/encoded_modules/module_koi8_r.py",
+    "Lib/test/test_fstring.py",
+    "Lib/test/test_grammar.py",
+    "Lib/test/test_importlib/test_util.py",
+    "Lib/test/test_named_expressions.py",
+    "Lib/test/test_patma.py",
+    "Lib/test/test_source_encoding.py",
+    "Tools/c-analyzer/c_parser/parser/_delim.py",
+    "Tools/i18n/pygettext.py",
+    "Tools/test2to3/maintest.py",
+    "Tools/test2to3/setup.py",
+    "Tools/test2to3/test/test_foo.py",
+    "Tools/test2to3/test2to3/hello.py",
 ]
 ```

@@ -278,17 +328,21 @@ Next, to benchmark the release build:
 ```shell
 cargo build --release

-hyperfine --ignore-failure --warmup 1 \
+hyperfine --ignore-failure --warmup 10 --runs 100 \
  "./target/release/ruff ./resources/test/cpython/ --no-cache" \
  "./target/release/ruff ./resources/test/cpython/"

 Benchmark 1: ./target/release/ruff ./resources/test/cpython/ --no-cache
-  Time (mean ± σ):     353.6 ms ±   7.6 ms    [User: 2868.8 ms, System: 171.5 ms]
-  Range (min … max):   344.4 ms … 367.3 ms    10 runs
+  Time (mean ± σ):     297.4 ms ±   4.9 ms    [User: 2460.0 ms, System: 67.2 ms]
+  Range (min … max):   287.7 ms … 312.1 ms    100 runs
+
+  Warning: Ignoring non-zero exit code.

 Benchmark 2: ./target/release/ruff ./resources/test/cpython/
-  Time (mean ± σ):      59.6 ms ±   2.5 ms    [User: 36.4 ms, System: 345.6 ms]
-  Range (min … max):    55.9 ms …  67.0 ms    48 runs
+  Time (mean ± σ):      79.6 ms ±   7.3 ms    [User: 59.7 ms, System: 356.1 ms]
+  Range (min … max):    62.4 ms … 111.2 ms    100 runs
+
+  Warning: Ignoring non-zero exit code.
 ```

 To benchmark against the ecosystem's existing tools:
@@ -300,11 +354,8 @@ hyperfine --ignore-failure --warmup 5 \
  "pyflakes resources/test/cpython" \
  "autoflake --recursive --expand-star-imports --remove-all-unused-imports --remove-unused-variables --remove-duplicate-keys resources/test/cpython" \
  "pycodestyle resources/test/cpython" \
-  "pycodestyle --select E501 resources/test/cpython" \
  "flake8 resources/test/cpython" \
-  "flake8 --select=F831,F541,F634,F403,F706,F901,E501 resources/test/cpython" \
-  "python -m scripts.run_flake8 resources/test/cpython" \
-  "python -m scripts.run_flake8 resources/test/cpython --select=F831,F541,F634,F403,F706,F901,E501"
+  "python -m scripts.run_flake8 resources/test/cpython"
 ```

 In order, these evaluate:
@@ -314,66 +365,58 @@ In order, these evaluate:
 - PyFlakes
 - autoflake
 - pycodestyle
- pycodestyle, limited to the checks supported by ruff
 - Flake8
- Flake8, limited to the checks supported by ruff
 - Flake8, with a hack to enable multiprocessing on macOS
- Flake8, with a hack to enable multiprocessing on macOS, limited to the checks supported by ruff

 (You can `poetry install` from `./scripts` to create a working environment for the above.)

 ```shell
 Benchmark 1: ./target/release/ruff ./resources/test/cpython/ --no-cache
-  Time (mean ± σ):     469.3 ms ±  16.3 ms    [User: 2663.0 ms, System: 972.5 ms]
-  Range (min … max):   445.2 ms … 494.8 ms    10 runs
+  Time (mean ± σ):     297.9 ms ±   7.0 ms    [User: 2436.6 ms, System: 65.9 ms]
+  Range (min … max):   289.9 ms … 314.6 ms    10 runs
+
+  Warning: Ignoring non-zero exit code.

 Benchmark 2: pylint --recursive=y resources/test/cpython/
-  Time (mean ± σ):     27.211 s ±  0.097 s    [User: 26.405 s, System: 0.799 s]
-  Range (min … max):   27.056 s … 27.349 s    10 runs
+  Time (mean ± σ):     37.634 s ±  0.225 s    [User: 36.728 s, System: 0.853 s]
+  Range (min … max):   37.201 s … 38.106 s    10 runs
+
+  Warning: Ignoring non-zero exit code.

 Benchmark 3: pyflakes resources/test/cpython
-  Time (mean ± σ):     27.309 s ±  0.033 s    [User: 27.137 s, System: 0.169 s]
-  Range (min … max):   27.267 s … 27.372 s    10 runs
+  Time (mean ± σ):     40.950 s ±  0.449 s    [User: 40.688 s, System: 0.229 s]
+  Range (min … max):   40.348 s … 41.671 s    10 runs
+
+  Warning: Ignoring non-zero exit code.

 Benchmark 4: autoflake --recursive --expand-star-imports --remove-all-unused-imports --remove-unused-variables --remove-duplicate-keys resources/test/cpython
-  Time (mean ± σ):      8.027 s ±  0.024 s    [User: 74.255 s, System: 0.953 s]
-  Range (min … max):    7.969 s …  8.052 s    10 runs
+  Time (mean ± σ):     11.562 s ±  0.160 s    [User: 107.022 s, System: 1.143 s]
+  Range (min … max):   11.417 s … 11.917 s    10 runs

 Benchmark 5: pycodestyle resources/test/cpython
-  Time (mean ± σ):     41.666 s ±  0.266 s    [User: 41.531 s, System: 0.132 s]
-  Range (min … max):   41.295 s … 41.980 s    10 runs
+  Time (mean ± σ):     67.428 s ±  0.985 s    [User: 67.199 s, System: 0.203 s]
+  Range (min … max):   65.313 s … 68.496 s    10 runs

-Benchmark 6: pycodestyle --select E501 resources/test/cpython
-  Time (mean ± σ):     14.547 s ±  0.077 s    [User: 14.466 s, System: 0.079 s]
-  Range (min … max):   14.429 s … 14.695 s    10 runs
+  Warning: Ignoring non-zero exit code.

-Benchmark 7: flake8 resources/test/cpython
-  Time (mean ± σ):     75.700 s ±  0.152 s    [User: 75.254 s, System: 0.440 s]
-  Range (min … max):   75.513 s … 76.014 s    10 runs
+Benchmark 6: flake8 resources/test/cpython
+  Time (mean ± σ):     116.099 s ±  1.178 s    [User: 115.217 s, System: 0.845 s]
+  Range (min … max):   114.180 s … 117.724 s    10 runs

-Benchmark 8: flake8 --select=F831,F541,F634,F403,F706,F901,E501 resources/test/cpython
-  Time (mean ± σ):     75.122 s ±  0.532 s    [User: 74.677 s, System: 0.440 s]
-  Range (min … max):   74.130 s … 75.606 s    10 runs
+  Warning: Ignoring non-zero exit code.

-Benchmark 9: python -m scripts.run_flake8 resources/test/cpython
-  Time (mean ± σ):     12.794 s ±  0.147 s    [User: 90.792 s, System: 0.738 s]
-  Range (min … max):   12.606 s … 13.030 s    10 runs
-
-Benchmark 10: python -m scripts.run_flake8 resources/test/cpython --select=F831,F541,F634,F403,F706,F901,E501
-  Time (mean ± σ):     12.487 s ±  0.118 s    [User: 90.052 s, System: 0.714 s]
-  Range (min … max):   12.265 s … 12.665 s    10 runs
+Benchmark 7: python -m scripts.run_flake8 resources/test/cpython
+  Time (mean ± σ):     20.477 s ±  0.349 s    [User: 142.372 s, System: 1.504 s]
+  Range (min … max):   20.107 s … 21.183 s    10 runs

 Summary
  './target/release/ruff ./resources/test/cpython/ --no-cache' ran
-   17.10 ± 0.60 times faster than 'autoflake --recursive --expand-star-imports --remove-all-unused-imports --remove-unused-variables --remove-duplicate-keys resources/test/cpython'
-   26.60 ± 0.96 times faster than 'python -m scripts.run_flake8 resources/test/cpython --select=F831,F541,F634,F403,F706,F901,E501'
-   27.26 ± 1.00 times faster than 'python -m scripts.run_flake8 resources/test/cpython'
-   30.99 ± 1.09 times faster than 'pycodestyle --select E501 resources/test/cpython'
-   57.98 ± 2.03 times faster than 'pylint --recursive=y resources/test/cpython/'
-   58.19 ± 2.02 times faster than 'pyflakes resources/test/cpython'
-   88.77 ± 3.14 times faster than 'pycodestyle resources/test/cpython'
-  160.06 ± 5.68 times faster than 'flake8 --select=F831,F541,F634,F403,F706,F901,E501 resources/test/cpython'
-  161.29 ± 5.61 times faster than 'flake8 resources/test/cpython'
+   38.81 ± 1.05 times faster than 'autoflake --recursive --expand-star-imports --remove-all-unused-imports --remove-unused-variables --remove-duplicate-keys resources/test/cpython'
+   68.74 ± 1.99 times faster than 'python -m scripts.run_flake8 resources/test/cpython'
+  126.33 ± 3.05 times faster than 'pylint --recursive=y resources/test/cpython/'
+  137.46 ± 3.55 times faster than 'pyflakes resources/test/cpython'
+  226.35 ± 6.23 times faster than 'pycodestyle resources/test/cpython'
+  389.73 ± 9.92 times faster than 'flake8 resources/test/cpython'
 ```

 ## License
--- a/resources/test/fixtures/E501.py
+++ b/resources/test/fixtures/E501.py
@@ -5,5 +5,12 @@
 Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
 """

+_ = """Lorem ipsum dolor sit amet.
+
+    https://github.com/PyCQA/pycodestyle/pull/258/files#diff-841c622497a8033d10152bfdfb15b20b92437ecdea21a260944ea86b77b51533
+
+Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
+"""  # noqa: E501
+
 _ = "---------------------------------------------------------------------------AAAAAAA"
 _ = "---------------------------------------------------------------------------亜亜亜亜亜亜亜"
--- a/resources/test/fixtures/F402.py
+++ b/resources/test/fixtures/F402.py
@@ -0,0 +1,9 @@
+import os
+import os.path as path
+
+
+for os in range(3):
+    pass
+
+for path in range(3):
+    pass
--- a/resources/test/fixtures/F405.py
+++ b/resources/test/fixtures/F405.py
@@ -0,0 +1,11 @@
+from mymodule import *
+
+
+def print_name():
+    print(name)
+
+
+def print_name(name):
+    print(name)
+
+__all__ = ['a']
--- a/resources/test/fixtures/F821.py
+++ b/resources/test/fixtures/F821.py
@@ -82,3 +82,10 @@ class Ticket:
 def update_tomato():
    print(TOMATO)
    TOMATO = "cherry tomato"
+
+
+A = f'{B}'
+A = (
+    f'B'
+    f'{B}'
+)
--- a/resources/test/fixtures/M001.py
+++ b/resources/test/fixtures/M001.py
@@ -0,0 +1,57 @@
+def f() -> None:
+    # Valid
+    a = 1  # noqa
+
+    # Valid
+    b = 2  # noqa: F841
+
+    # Invalid
+    c = 1  # noqa
+    print(c)
+
+    # Invalid
+    d = 1  # noqa: E501
+
+    # Invalid
+    d = 1  # noqa: F841, E501
+
+
+# Valid
+_ = """Lorem ipsum dolor sit amet.
+
+    https://github.com/PyCQA/pycodestyle/pull/258/files#diff-841c622497a8033d10152bfdfb15b20b92437ecdea21a260944ea86b77b51533
+
+Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
+"""  # noqa: E501
+
+# Valid
+_ = """Lorem ipsum dolor sit amet.
+
+    https://github.com/PyCQA/pycodestyle/pull/258/files#diff-841c622497a8033d10152bfdfb15b20b92437ecdea21a260944ea86b77b51533
+
+Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
+"""  # noqa
+
+# Invalid
+_ = """Lorem ipsum dolor sit amet.
+
+    https://github.com/PyCQA/pycodestyle/pull/258/files#diff-841c622497a8033d10152bfdfb15b20b92437ecdea21a260944ea86b77b51533
+
+Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
+"""  # noqa: E501, F841
+
+# Invalid
+_ = """Lorem ipsum dolor sit amet.
+
+    https://github.com/PyCQA/pycodestyle/pull/258/files#diff-841c622497a8033d10152bfdfb15b20b92437ecdea21a260944ea86b77b51533
+
+Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor.
+"""  # noqa: E501
+
+# Invalid
+_ = """Lorem ipsum dolor sit amet.
+
+    https://github.com/PyCQA/pycodestyle/pull/258/files#diff-841c622497a8033d10152bfdfb15b20b92437ecdea21a260944ea86b77b51533
+
+Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor.
+"""  # noqa
--- a/src/ast/checks.rs
+++ b/src/ast/checks.rs
@@ -7,7 +7,7 @@ use rustpython_parser::ast::{
 };

 use crate::ast::operations::SourceCodeLocator;
-use crate::ast::types::{Binding, BindingKind, FunctionScope, Scope, ScopeKind};
+use crate::ast::types::{Binding, BindingKind, CheckLocator, FunctionScope, Scope, ScopeKind};
 use crate::autofix::{fixer, fixes};
 use crate::checks::{Check, CheckKind, Fix, RejectedCmpop};

@@ -37,6 +37,7 @@ pub fn check_not_tests(
    operand: &Expr,
    check_not_in: bool,
    check_not_is: bool,
+    locator: &dyn CheckLocator,
 ) -> Vec<Check> {
    let mut checks: Vec<Check> = vec![];

@@ -46,12 +47,18 @@ pub fn check_not_tests(
                match op {
                    Cmpop::In => {
                        if check_not_in {
-                            checks.push(Check::new(CheckKind::NotInTest, operand.location));
+                            checks.push(Check::new(
+                                CheckKind::NotInTest,
+                                locator.locate_check(operand.location),
+                            ));
                        }
                    }
                    Cmpop::Is => {
                        if check_not_is {
-                            checks.push(Check::new(CheckKind::NotIsTest, operand.location));
+                            checks.push(Check::new(
+                                CheckKind::NotIsTest,
+                                locator.locate_check(operand.location),
+                            ));
                        }
                    }
                    _ => {}
@@ -64,7 +71,7 @@ pub fn check_not_tests(
 }

 /// Check UnusedVariable compliance.
-pub fn check_unused_variables(scope: &Scope) -> Vec<Check> {
+pub fn check_unused_variables(scope: &Scope, locator: &dyn CheckLocator) -> Vec<Check> {
    let mut checks: Vec<Check> = vec![];

    if matches!(
@@ -85,7 +92,7 @@ pub fn check_unused_variables(scope: &Scope) -> Vec<Check> {
        {
            checks.push(Check::new(
                CheckKind::UnusedVariable(name.to_string()),
-                binding.location,
+                locator.locate_check(binding.location),
            ));
        }
    }
@@ -299,6 +306,7 @@ pub fn check_repeated_keys(
    keys: &Vec<Expr>,
    check_repeated_literals: bool,
    check_repeated_variables: bool,
+    locator: &dyn CheckLocator,
 ) -> Vec<Check> {
    let mut checks: Vec<Check> = vec![];

@@ -313,7 +321,7 @@ pub fn check_repeated_keys(
                    if check_repeated_literals && v1 == v2 {
                        checks.push(Check::new(
                            CheckKind::MultiValueRepeatedKeyLiteral,
-                            k2.location,
+                            locator.locate_check(k2.location),
                        ))
                    }
                }
@@ -321,7 +329,7 @@ pub fn check_repeated_keys(
                    if check_repeated_variables && v1 == v2 {
                        checks.push(Check::new(
                            CheckKind::MultiValueRepeatedKeyVariable((*v2).to_string()),
-                            k2.location,
+                            locator.locate_check(k2.location),
                        ))
                    }
                }
@@ -340,6 +348,7 @@ pub fn check_literal_comparisons(
    comparators: &Vec<Expr>,
    check_none_comparisons: bool,
    check_true_false_comparisons: bool,
+    locator: &dyn CheckLocator,
 ) -> Vec<Check> {
    let mut checks: Vec<Check> = vec![];

@@ -359,13 +368,13 @@ pub fn check_literal_comparisons(
        if matches!(op, Cmpop::Eq) {
            checks.push(Check::new(
                CheckKind::NoneComparison(RejectedCmpop::Eq),
-                comparator.location,
+                locator.locate_check(comparator.location),
            ));
        }
        if matches!(op, Cmpop::NotEq) {
            checks.push(Check::new(
                CheckKind::NoneComparison(RejectedCmpop::NotEq),
-                comparator.location,
+                locator.locate_check(comparator.location),
            ));
        }
    }
@@ -379,13 +388,13 @@ pub fn check_literal_comparisons(
            if matches!(op, Cmpop::Eq) {
                checks.push(Check::new(
                    CheckKind::TrueFalseComparison(value, RejectedCmpop::Eq),
-                    comparator.location,
+                    locator.locate_check(comparator.location),
                ));
            }
            if matches!(op, Cmpop::NotEq) {
                checks.push(Check::new(
                    CheckKind::TrueFalseComparison(value, RejectedCmpop::NotEq),
-                    comparator.location,
+                    locator.locate_check(comparator.location),
                ));
            }
        }
@@ -405,13 +414,13 @@ pub fn check_literal_comparisons(
            if matches!(op, Cmpop::Eq) {
                checks.push(Check::new(
                    CheckKind::NoneComparison(RejectedCmpop::Eq),
-                    comparator.location,
+                    locator.locate_check(comparator.location),
                ));
            }
            if matches!(op, Cmpop::NotEq) {
                checks.push(Check::new(
                    CheckKind::NoneComparison(RejectedCmpop::NotEq),
-                    comparator.location,
+                    locator.locate_check(comparator.location),
                ));
            }
        }
@@ -425,13 +434,13 @@ pub fn check_literal_comparisons(
                if matches!(op, Cmpop::Eq) {
                    checks.push(Check::new(
                        CheckKind::TrueFalseComparison(value, RejectedCmpop::Eq),
-                        comparator.location,
+                        locator.locate_check(comparator.location),
                    ));
                }
                if matches!(op, Cmpop::NotEq) {
                    checks.push(Check::new(
                        CheckKind::TrueFalseComparison(value, RejectedCmpop::NotEq),
-                        comparator.location,
+                        locator.locate_check(comparator.location),
                    ));
                }
            }
@@ -528,9 +537,9 @@ pub fn check_type_comparison(
 /// Check TwoStarredExpressions and TooManyExpressionsInStarredAssignment compliance.
 pub fn check_starred_expressions(
    elts: &[Expr],
-    location: Location,
    check_too_many_expressions: bool,
    check_two_starred_expressions: bool,
+    location: Location,
 ) -> Option<Check> {
    let mut has_starred: bool = false;
    let mut starred_index: Option<usize> = None;
@@ -563,6 +572,7 @@ pub fn check_break_outside_loop(
    stmt: &Stmt,
    parents: &[&Stmt],
    parent_stack: &[usize],
+    locator: &dyn CheckLocator,
 ) -> Option<Check> {
    let mut allowed: bool = false;
    let mut parent = stmt;
@@ -589,7 +599,10 @@ pub fn check_break_outside_loop(
    }

    if !allowed {
-        Some(Check::new(CheckKind::BreakOutsideLoop, stmt.location))
+        Some(Check::new(
+            CheckKind::BreakOutsideLoop,
+            locator.locate_check(stmt.location),
+        ))
    } else {
        None
    }
@@ -600,6 +613,7 @@ pub fn check_continue_outside_loop(
    stmt: &Stmt,
    parents: &[&Stmt],
    parent_stack: &[usize],
+    locator: &dyn CheckLocator,
 ) -> Option<Check> {
    let mut allowed: bool = false;
    let mut parent = stmt;
@@ -626,7 +640,10 @@ pub fn check_continue_outside_loop(
    }

    if !allowed {
-        Some(Check::new(CheckKind::ContinueOutsideLoop, stmt.location))
+        Some(Check::new(
+            CheckKind::ContinueOutsideLoop,
+            locator.locate_check(stmt.location),
+        ))
    } else {
        None
    }
--- a/src/ast/types.rs
+++ b/src/ast/types.rs
@@ -25,6 +25,7 @@ pub enum ScopeKind {
 pub struct Scope {
    pub id: usize,
    pub kind: ScopeKind,
+    pub import_starred: bool,
    pub values: BTreeMap<String, Binding>,
 }

@@ -33,6 +34,7 @@ impl Scope {
        Scope {
            id: id(),
            kind,
+            import_starred: false,
            values: BTreeMap::new(),
        }
    }
@@ -44,6 +46,7 @@ pub enum BindingKind {
    Argument,
    Assignment,
    Binding,
+    LoopVar,
    Builtin,
    ClassDefinition,
    Definition,
@@ -62,3 +65,7 @@ pub struct Binding {
    /// last used.
    pub used: Option<(usize, Location)>,
 }
+
+pub trait CheckLocator {
+    fn locate_check(&self, default: Location) -> Location;
+}
--- a/src/check_ast.rs
+++ b/src/check_ast.rs
@@ -9,7 +9,7 @@ use rustpython_parser::parser;

 use crate::ast::operations::{extract_all_names, SourceCodeLocator};
 use crate::ast::relocate::relocate_expr;
-use crate::ast::types::{Binding, BindingKind, FunctionScope, Scope, ScopeKind};
+use crate::ast::types::{Binding, BindingKind, CheckLocator, FunctionScope, Scope, ScopeKind};
 use crate::ast::visitor::{walk_excepthandler, Visitor};
 use crate::ast::{checks, operations, visitor};
 use crate::autofix::fixer;
@@ -42,7 +42,7 @@ struct Checker<'a> {
    deferred_lambdas: Vec<(&'a Expr, Vec<usize>, Vec<usize>)>,
    deferred_assignments: Vec<usize>,
    // Derivative state.
-    in_f_string: bool,
+    in_f_string: Option<Location>,
    in_annotation: bool,
    in_literal: bool,
    seen_non_import: bool,
@@ -74,7 +74,7 @@ impl<'a> Checker<'a> {
            deferred_functions: vec![],
            deferred_lambdas: vec![],
            deferred_assignments: vec![],
-            in_f_string: false,
+            in_f_string: None,
            in_annotation: false,
            in_literal: false,
            seen_non_import: false,
@@ -171,7 +171,6 @@ where
        // Pre-visit.
        match &stmt.node {
            StmtKind::Global { names } | StmtKind::Nonlocal { names } => {
-                // TODO(charlie): Handle doctests.
                let global_scope_id = self.scopes[GLOBAL_SCOPE_INDEX].id;

                let current_scope =
@@ -193,25 +192,34 @@ where
                }

                if self.settings.select.contains(&CheckCode::E741) {
-                    self.checks.extend(names.iter().filter_map(|name| {
-                        checks::check_ambiguous_variable_name(name, stmt.location)
-                    }));
+                    let location = self.locate_check(stmt.location);
+                    self.checks.extend(
+                        names.iter().filter_map(|name| {
+                            checks::check_ambiguous_variable_name(name, location)
+                        }),
+                    );
                }
            }
            StmtKind::Break => {
                if self.settings.select.contains(&CheckCode::F701) {
-                    if let Some(check) =
-                        checks::check_break_outside_loop(stmt, &self.parents, &self.parent_stack)
-                    {
+                    if let Some(check) = checks::check_break_outside_loop(
+                        stmt,
+                        &self.parents,
+                        &self.parent_stack,
+                        self,
+                    ) {
                        self.checks.push(check);
                    }
                }
            }
            StmtKind::Continue => {
                if self.settings.select.contains(&CheckCode::F702) {
-                    if let Some(check) =
-                        checks::check_continue_outside_loop(stmt, &self.parents, &self.parent_stack)
-                    {
+                    if let Some(check) = checks::check_continue_outside_loop(
+                        stmt,
+                        &self.parents,
+                        &self.parent_stack,
+                        self,
+                    ) {
                        self.checks.push(check);
                    }
                }
@@ -231,8 +239,10 @@ where
                ..
            } => {
                if self.settings.select.contains(&CheckCode::E743) {
-                    if let Some(check) = checks::check_ambiguous_function_name(name, stmt.location)
-                    {
+                    if let Some(check) = checks::check_ambiguous_function_name(
+                        name,
+                        self.locate_check(stmt.location),
+                    ) {
                        self.checks.push(check);
                    }
                }
@@ -293,7 +303,7 @@ where
                            ScopeKind::Class | ScopeKind::Module => {
                                self.checks.push(Check::new(
                                    CheckKind::ReturnOutsideFunction,
-                                    stmt.location,
+                                    self.locate_check(stmt.location),
                                ));
                            }
                            _ => {}
@@ -325,7 +335,9 @@ where
                }

                if self.settings.select.contains(&CheckCode::E742) {
-                    if let Some(check) = checks::check_ambiguous_class_name(name, stmt.location) {
+                    if let Some(check) =
+                        checks::check_ambiguous_class_name(name, self.locate_check(stmt.location))
+                    {
                        self.checks.push(check);
                    }
                }
@@ -351,7 +363,7 @@ where
                {
                    self.checks.push(Check::new(
                        CheckKind::ModuleImportNotAtTopOfFile,
-                        stmt.location,
+                        self.locate_check(stmt.location),
                    ));
                }

@@ -391,7 +403,11 @@ where
                    }
                }
            }
-            StmtKind::ImportFrom { names, module, .. } => {
+            StmtKind::ImportFrom {
+                names,
+                module,
+                level,
+            } => {
                if self
                    .settings
                    .select
@@ -401,7 +417,7 @@ where
                {
                    self.checks.push(Check::new(
                        CheckKind::ModuleImportNotAtTopOfFile,
-                        stmt.location,
+                        self.locate_check(stmt.location),
                    ));
                }

@@ -437,18 +453,26 @@ where
                        {
                            self.checks.push(Check::new(
                                CheckKind::FutureFeatureNotDefined(alias.node.name.to_string()),
-                                stmt.location,
+                                self.locate_check(stmt.location),
                            ));
                        }

                        if self.settings.select.contains(&CheckCode::F404) && !self.futures_allowed
                        {
-                            self.checks
-                                .push(Check::new(CheckKind::LateFutureImport, stmt.location));
+                            self.checks.push(Check::new(
+                                CheckKind::LateFutureImport,
+                                self.locate_check(stmt.location),
+                            ));
                        }
                    } else if alias.node.name == "*" {
+                        let module_name = format!(
+                            "{}{}",
+                            ".".repeat(level.unwrap_or_default()),
+                            module.clone().unwrap_or_else(|| "module".to_string()),
+                        );
+
                        self.add_binding(
-                            name,
+                            module_name.to_string(),
                            Binding {
                                kind: BindingKind::StarImportation,
                                used: None,
@@ -456,27 +480,29 @@ where
                            },
                        );

-                        if self.settings.select.contains(&CheckCode::F403) {
-                            self.checks.push(Check::new(
-                                CheckKind::ImportStarUsage(
-                                    module.clone().unwrap_or_else(|| "module".to_string()),
-                                ),
-                                stmt.location,
-                            ));
-                        }
-
                        if self.settings.select.contains(&CheckCode::F406) {
                            let scope = &self.scopes
                                [*(self.scope_stack.last().expect("No current scope found."))];
                            if !matches!(scope.kind, ScopeKind::Module) {
                                self.checks.push(Check::new(
-                                    CheckKind::ImportStarNotPermitted(
-                                        module.clone().unwrap_or_else(|| "module".to_string()),
-                                    ),
-                                    stmt.location,
+                                    CheckKind::ImportStarNotPermitted(module_name.to_string()),
+                                    self.locate_check(stmt.location),
                                ));
                            }
                        }
+
+                        if self.settings.select.contains(&CheckCode::F403) {
+                            self.checks.push(Check::new(
+                                CheckKind::ImportStarUsed(module_name.to_string()),
+                                self.locate_check(stmt.location),
+                            ));
+                        }
+
+                        let scope = &mut self.scopes[*(self
+                            .scope_stack
+                            .last_mut()
+                            .expect("No current scope found."))];
+                        scope.import_starred = true;
                    } else {
                        let binding = Binding {
                            kind: BindingKind::Importation(match module {
@@ -504,14 +530,18 @@ where
            }
            StmtKind::If { test, .. } => {
                if self.settings.select.contains(&CheckCode::F634) {
-                    if let Some(check) = checks::check_if_tuple(test, stmt.location) {
+                    if let Some(check) =
+                        checks::check_if_tuple(test, self.locate_check(stmt.location))
+                    {
                        self.checks.push(check);
                    }
                }
            }
            StmtKind::Assert { test, .. } => {
                if self.settings.select.contains(CheckKind::AssertTuple.code()) {
-                    if let Some(check) = checks::check_assert_tuple(test, stmt.location) {
+                    if let Some(check) =
+                        checks::check_assert_tuple(test, self.locate_check(stmt.location))
+                    {
                        self.checks.push(check);
                    }
                }
@@ -525,7 +555,9 @@ where
            }
            StmtKind::Assign { value, .. } => {
                if self.settings.select.contains(&CheckCode::E731) {
-                    if let Some(check) = checks::check_do_not_assign_lambda(value, stmt.location) {
+                    if let Some(check) =
+                        checks::check_do_not_assign_lambda(value, self.locate_check(stmt.location))
+                    {
                        self.checks.push(check);
                    }
                }
@@ -533,9 +565,10 @@ where
            StmtKind::AnnAssign { value, .. } => {
                if self.settings.select.contains(&CheckCode::E731) {
                    if let Some(value) = value {
-                        if let Some(check) =
-                            checks::check_do_not_assign_lambda(value, stmt.location)
-                        {
+                        if let Some(check) = checks::check_do_not_assign_lambda(
+                            value,
+                            self.locate_check(stmt.location),
+                        ) {
                            self.checks.push(check);
                        }
                    }
@@ -590,7 +623,6 @@ where
        let prev_in_literal = self.in_literal;
        let prev_in_annotation = self.in_annotation;

-        // Important:
        if self.in_annotation && self.annotations_future_enabled {
            self.deferred_annotations.push((
                expr,
@@ -616,9 +648,9 @@ where
                        self.settings.select.contains(&CheckCode::F622);
                    if let Some(check) = checks::check_starred_expressions(
                        elts,
-                        expr.location,
                        check_too_many_expressions,
                        check_two_starred_expressions,
+                        self.locate_check(expr.location),
                    ) {
                        self.checks.push(check);
                    }
@@ -628,9 +660,10 @@ where
                ExprContext::Load => self.handle_node_load(expr),
                ExprContext::Store => {
                    if self.settings.select.contains(&CheckCode::E741) {
-                        if let Some(check) =
-                            checks::check_ambiguous_variable_name(id, expr.location)
-                        {
+                        if let Some(check) = checks::check_ambiguous_variable_name(
+                            id,
+                            self.locate_check(expr.location),
+                        ) {
                            self.checks.push(check);
                        }
                    }
@@ -661,18 +694,6 @@ where
                        }
                    }
                }
-
-                //
-                // if id == "locals" {
-                //     let scope = &self.scopes
-                //         [*(self.scope_stack.last().expect("No current scope found."))];
-                //     if matches!(scope.kind, ScopeKind::Function(_)) {
-                //     let parent =
-                //         self.parents[*(self.parent_stack.last().expect("No parent found."))];
-                //         if matches!(parent.node, StmtKind::Call)
-                //     }
-                //
-                // }
            }
            ExprKind::Dict { keys, .. } => {
                let check_repeated_literals = self.settings.select.contains(&CheckCode::F601);
@@ -682,6 +703,7 @@ where
                        keys,
                        check_repeated_literals,
                        check_repeated_variables,
+                        self,
                    ));
                }
            }
@@ -694,12 +716,14 @@ where
                    .contains(CheckKind::YieldOutsideFunction.code())
                    && matches!(scope.kind, ScopeKind::Class | ScopeKind::Module)
                {
-                    self.checks
-                        .push(Check::new(CheckKind::YieldOutsideFunction, expr.location));
+                    self.checks.push(Check::new(
+                        CheckKind::YieldOutsideFunction,
+                        self.locate_check(expr.location),
+                    ));
                }
            }
            ExprKind::JoinedStr { values } => {
-                if !self.in_f_string
+                if self.in_f_string.is_none()
                    && self
                        .settings
                        .select
@@ -710,10 +734,10 @@ where
                {
                    self.checks.push(Check::new(
                        CheckKind::FStringMissingPlaceholders,
-                        expr.location,
+                        self.locate_check(expr.location),
                    ));
                }
-                self.in_f_string = true;
+                self.in_f_string = Some(expr.location);
            }
            ExprKind::BinOp {
                left,
@@ -746,6 +770,7 @@ where
                        operand,
                        check_not_in,
                        check_not_is,
+                        self,
                    ));
                }
            }
@@ -763,6 +788,7 @@ where
                        comparators,
                        check_none_comparisons,
                        check_true_false_comparisons,
+                        self,
                    ));
                }

@@ -771,7 +797,7 @@ where
                        left,
                        ops,
                        comparators,
-                        expr.location,
+                        self.locate_check(expr.location),
                    ));
                }

@@ -779,7 +805,7 @@ where
                    self.checks.extend(checks::check_type_comparison(
                        ops,
                        comparators,
-                        expr.location,
+                        self.locate_check(expr.location),
                    ));
                }
            }
@@ -944,9 +970,10 @@ where
                match name {
                    Some(name) => {
                        if self.settings.select.contains(&CheckCode::E741) {
-                            if let Some(check) =
-                                checks::check_ambiguous_variable_name(name, excepthandler.location)
-                            {
+                            if let Some(check) = checks::check_ambiguous_variable_name(
+                                name,
+                                self.locate_check(excepthandler.location),
+                            ) {
                                self.checks.push(check);
                            }
                        }
@@ -1046,14 +1073,22 @@ where
        );

        if self.settings.select.contains(&CheckCode::E741) {
-            if let Some(check) = checks::check_ambiguous_variable_name(&arg.node.arg, arg.location)
-            {
+            if let Some(check) = checks::check_ambiguous_variable_name(
+                &arg.node.arg,
+                self.locate_check(arg.location),
+            ) {
                self.checks.push(check);
            }
        }
    }
 }

+impl CheckLocator for Checker<'_> {
+    fn locate_check(&self, default: Location) -> Location {
+        self.in_f_string.unwrap_or(default)
+    }
+}
+
 impl<'a> Checker<'a> {
    fn push_parent(&mut self, parent: &'a Stmt) {
        self.parent_stack.push(self.parents.len());
@@ -1110,12 +1145,24 @@ impl<'a> Checker<'a> {
        // TODO(charlie): Don't treat annotations as assignments if there is an existing value.
        let binding = match scope.values.get(&name) {
            None => binding,
-            Some(existing) => Binding {
-                kind: binding.kind,
-                location: binding.location,
-                used: existing.used,
-            },
+            Some(existing) => {
+                if self.settings.select.contains(&CheckCode::F402)
+                    && matches!(existing.kind, BindingKind::Importation(_))
+                    && matches!(binding.kind, BindingKind::LoopVar)
+                {
+                    self.checks.push(Check::new(
+                        CheckKind::ImportShadowedByLoopVar(name.clone(), existing.location.row()),
+                        binding.location,
+                    ));
+                }
+                Binding {
+                    kind: binding.kind,
+                    location: binding.location,
+                    used: existing.used,
+                }
+            }
        };
+
        scope.values.insert(name, binding);
    }

@@ -1126,6 +1173,7 @@ impl<'a> Checker<'a> {

            let mut first_iter = true;
            let mut in_generator = false;
+            let mut import_starred = false;
            for scope_index in self.scope_stack.iter().rev() {
                let scope = &mut self.scopes[*scope_index];
                if matches!(scope.kind, ScopeKind::Class) {
@@ -1142,6 +1190,28 @@ impl<'a> Checker<'a> {

                first_iter = false;
                in_generator = matches!(scope.kind, ScopeKind::Generator);
+                import_starred = import_starred || scope.import_starred;
+            }
+
+            if import_starred {
+                if self.settings.select.contains(&CheckCode::F405) {
+                    let mut from_list = vec![];
+                    for scope_index in self.scope_stack.iter().rev() {
+                        let scope = &self.scopes[*scope_index];
+                        for (name, binding) in scope.values.iter() {
+                            if matches!(binding.kind, BindingKind::StarImportation) {
+                                from_list.push(name.as_str());
+                            }
+                        }
+                    }
+                    from_list.sort();
+
+                    self.checks.push(Check::new(
+                        CheckKind::ImportStarUsage(id.clone(), from_list.join(", ")),
+                        self.locate_check(expr.location),
+                    ));
+                }
+                return;
            }

            if self.settings.select.contains(&CheckCode::F821) {
@@ -1151,7 +1221,7 @@ impl<'a> Checker<'a> {
                }
                self.checks.push(Check::new(
                    CheckKind::UndefinedName(id.clone()),
-                    expr.location,
+                    self.locate_check(expr.location),
                ))
            }
        }
@@ -1173,7 +1243,7 @@ impl<'a> Checker<'a> {
                                if scope_id == current.id {
                                    self.checks.push(Check::new(
                                        CheckKind::UndefinedLocal(id.clone()),
-                                        location,
+                                        self.locate_check(location),
                                    ));
                                }
                            }
@@ -1198,8 +1268,19 @@ impl<'a> Checker<'a> {
            if matches!(
                parent.node,
                StmtKind::For { .. } | StmtKind::AsyncFor { .. }
-            ) || operations::is_unpacking_assignment(parent)
-            {
+            ) {
+                self.add_binding(
+                    id.to_string(),
+                    Binding {
+                        kind: BindingKind::LoopVar,
+                        used: None,
+                        location: expr.location,
+                    },
+                );
+                return;
+            }
+
+            if operations::is_unpacking_assignment(parent) {
                self.add_binding(
                    id.to_string(),
                    Binding {
@@ -1255,7 +1336,7 @@ impl<'a> Checker<'a> {
            {
                self.checks.push(Check::new(
                    CheckKind::UndefinedName(id.clone()),
-                    expr.location,
+                    self.locate_check(expr.location),
                ))
            }
        }
@@ -1280,7 +1361,7 @@ impl<'a> Checker<'a> {
            } else if self.settings.select.contains(&CheckCode::F722) {
                self.checks.push(Check::new(
                    CheckKind::ForwardAnnotationSyntaxError(expression.to_string()),
-                    location,
+                    self.locate_check(location),
                ));
            }
        }
@@ -1332,17 +1413,18 @@ impl<'a> Checker<'a> {
    }

    fn check_deferred_assignments(&mut self) {
-        while let Some(index) = self.deferred_assignments.pop() {
-            if self.settings.select.contains(&CheckCode::F841) {
+        if self.settings.select.contains(&CheckCode::F841) {
+            while let Some(index) = self.deferred_assignments.pop() {
                self.checks
-                    .extend(checks::check_unused_variables(&self.scopes[index]));
+                    .extend(checks::check_unused_variables(&self.scopes[index], self));
            }
        }
    }

    fn check_dead_scopes(&mut self) {
-        if !self.settings.select.contains(&CheckCode::F822)
-            && !self.settings.select.contains(&CheckCode::F401)
+        if !self.settings.select.contains(&CheckCode::F401)
+            && !self.settings.select.contains(&CheckCode::F405)
+            && !self.settings.select.contains(&CheckCode::F822)
        {
            return;
        }
@@ -1357,15 +1439,39 @@ impl<'a> Checker<'a> {
            });

            if self.settings.select.contains(&CheckCode::F822)
+                && !scope.import_starred
                && !self.path.ends_with("__init__.py")
            {
-                if let Some(binding) = all_binding {
+                if let Some(all_binding) = all_binding {
                    if let Some(names) = all_names {
                        for name in names {
                            if !scope.values.contains_key(name) {
                                self.checks.push(Check::new(
                                    CheckKind::UndefinedExport(name.to_string()),
-                                    binding.location,
+                                    self.locate_check(all_binding.location),
+                                ));
+                            }
+                        }
+                    }
+                }
+            }
+
+            if self.settings.select.contains(&CheckCode::F405) && scope.import_starred {
+                if let Some(all_binding) = all_binding {
+                    if let Some(names) = all_names {
+                        let mut from_list = vec![];
+                        for (name, binding) in scope.values.iter() {
+                            if matches!(binding.kind, BindingKind::StarImportation) {
+                                from_list.push(name.as_str());
+                            }
+                        }
+                        from_list.sort();
+
+                        for name in names {
+                            if !scope.values.contains_key(name) {
+                                self.checks.push(Check::new(
+                                    CheckKind::ImportStarUsage(name.clone(), from_list.join(", ")),
+                                    self.locate_check(all_binding.location),
                                ));
                            }
                        }
@@ -1386,7 +1492,7 @@ impl<'a> Checker<'a> {
                            | BindingKind::SubmoduleImportation(full_name) => {
                                self.checks.push(Check::new(
                                    CheckKind::UnusedImport(full_name.to_string()),
-                                    binding.location,
+                                    self.locate_check(binding.location),
                                ));
                            }
                            _ => {}
--- a/src/check_lines.rs
+++ b/src/check_lines.rs
@@ -1,6 +1,11 @@
+use std::collections::BTreeMap;
+
 use rustpython_parser::ast::Location;

-use crate::checks::{Check, CheckCode, CheckKind};
+use crate::autofix::fixer;
+use crate::checks::{Check, CheckCode, CheckKind, Fix};
+use crate::noqa;
+use crate::noqa::Directive;
 use crate::settings::Settings;

 /// Whether the given line is too long and should be reported.
@@ -19,17 +24,58 @@ fn should_enforce_line_length(line: &str, length: usize, limit: usize) -> bool {
    }
 }

-pub fn check_lines(checks: &mut Vec<Check>, contents: &str, settings: &Settings) {
+pub fn check_lines(
+    checks: &mut Vec<Check>,
+    contents: &str,
+    noqa_line_for: &[usize],
+    settings: &Settings,
+    autofix: &fixer::Mode,
+) {
    let enforce_line_too_long = settings.select.contains(&CheckCode::E501);
+    let enforce_noqa = settings.select.contains(&CheckCode::M001);
+
+    let mut noqa_directives: BTreeMap<usize, (Directive, Vec<&str>)> = BTreeMap::new();

    let mut line_checks = vec![];
    let mut ignored = vec![];
-    for (row, line) in contents.lines().enumerate() {
+
+    let lines: Vec<&str> = contents.lines().collect();
+    for (lineno, line) in lines.iter().enumerate() {
+        // Grab the noqa (logical) line number for the current (physical) line.
+        // If there are newlines at the end of the file, they won't be represented in
+        // `noqa_line_for`, so fallback to the current line.
+        let noqa_lineno = noqa_line_for
+            .get(lineno)
+            .map(|lineno| lineno - 1)
+            .unwrap_or(lineno);
+
+        if enforce_noqa {
+            noqa_directives
+                .entry(noqa_lineno)
+                .or_insert_with(|| (noqa::extract_noqa_directive(lines[noqa_lineno]), vec![]));
+        }
+
        // Remove any ignored checks.
        // TODO(charlie): Only validate checks for the current line.
        for (index, check) in checks.iter().enumerate() {
-            if check.location.row() == row + 1 && check.is_inline_ignored(line) {
-                ignored.push(index);
+            if check.location.row() == lineno + 1 {
+                let noqa = noqa_directives
+                    .entry(noqa_lineno)
+                    .or_insert_with(|| (noqa::extract_noqa_directive(lines[noqa_lineno]), vec![]));
+
+                match noqa {
+                    (Directive::All(_), matches) => {
+                        matches.push(check.kind.code().as_str());
+                        ignored.push(index)
+                    }
+                    (Directive::Codes(_, codes), matches) => {
+                        if codes.contains(&check.kind.code().as_str()) {
+                            matches.push(check.kind.code().as_str());
+                            ignored.push(index);
+                        }
+                    }
+                    (Directive::None, _) => {}
+                }
            }
        }

@@ -37,16 +83,94 @@ pub fn check_lines(checks: &mut Vec<Check>, contents: &str, settings: &Settings)
        if enforce_line_too_long {
            let line_length = line.chars().count();
            if should_enforce_line_length(line, line_length, settings.line_length) {
+                let noqa = noqa_directives
+                    .entry(noqa_lineno)
+                    .or_insert_with(|| (noqa::extract_noqa_directive(lines[noqa_lineno]), vec![]));
+
                let check = Check::new(
                    CheckKind::LineTooLong(line_length, settings.line_length),
-                    Location::new(row + 1, settings.line_length + 1),
+                    Location::new(lineno + 1, settings.line_length + 1),
                );
-                if !check.is_inline_ignored(line) {
-                    line_checks.push(check);
+
+                match noqa {
+                    (Directive::All(_), matches) => {
+                        matches.push(check.kind.code().as_str());
+                    }
+                    (Directive::Codes(_, codes), matches) => {
+                        if codes.contains(&check.kind.code().as_str()) {
+                            matches.push(check.kind.code().as_str());
+                        } else {
+                            line_checks.push(check);
+                        }
+                    }
+                    (Directive::None, _) => line_checks.push(check),
                }
            }
        }
    }
+
+    // Enforce that the noqa directive was actually used.
+    if enforce_noqa {
+        for (row, (directive, matches)) in noqa_directives {
+            match directive {
+                Directive::All(column) => {
+                    if matches.is_empty() {
+                        let mut check = Check::new(
+                            CheckKind::UnusedNOQA(None),
+                            Location::new(row + 1, column + 1),
+                        );
+                        if matches!(autofix, fixer::Mode::Generate | fixer::Mode::Apply) {
+                            check.amend(Fix {
+                                content: "".to_string(),
+                                start: Location::new(row + 1, column + 1),
+                                end: Location::new(row + 1, lines[row].chars().count() + 1),
+                                applied: false,
+                            });
+                        }
+                        line_checks.push(check);
+                    }
+                }
+                Directive::Codes(column, codes) => {
+                    let mut invalid_codes = vec![];
+                    let mut valid_codes = vec![];
+                    for code in codes {
+                        if !matches.contains(&code) {
+                            invalid_codes.push(code);
+                        } else {
+                            valid_codes.push(code);
+                        }
+                    }
+
+                    if !invalid_codes.is_empty() {
+                        let mut check = Check::new(
+                            CheckKind::UnusedNOQA(Some(invalid_codes.join(", "))),
+                            Location::new(row + 1, column + 1),
+                        );
+                        if matches!(autofix, fixer::Mode::Generate | fixer::Mode::Apply) {
+                            if valid_codes.is_empty() {
+                                check.amend(Fix {
+                                    content: "".to_string(),
+                                    start: Location::new(row + 1, column + 1),
+                                    end: Location::new(row + 1, lines[row].chars().count() + 1),
+                                    applied: false,
+                                });
+                            } else {
+                                check.amend(Fix {
+                                    content: format!("  # noqa: {}", valid_codes.join(", ")),
+                                    start: Location::new(row + 1, column + 1),
+                                    end: Location::new(row + 1, lines[row].chars().count() + 1),
+                                    applied: false,
+                                });
+                            }
+                        }
+                        line_checks.push(check);
+                    }
+                }
+                Directive::None => {}
+            }
+        }
+    }
+
    ignored.sort();
    for index in ignored.iter().rev() {
        checks.swap_remove(*index);
@@ -56,22 +180,32 @@ pub fn check_lines(checks: &mut Vec<Check>, contents: &str, settings: &Settings)

 #[cfg(test)]
 mod tests {
+    use std::collections::BTreeSet;
+
    use super::check_lines;
    use super::*;
-    use std::collections::BTreeSet;

    #[test]
    fn e501_non_ascii_char() {
        let line = "'\u{4e9c}' * 2"; // 7 in UTF-32, 9 in UTF-8.
+        let noqa_line_for: Vec<usize> = vec![1];
        let check_with_max_line_length = |line_length: usize| {
            let mut checks: Vec<Check> = vec![];
            let settings = Settings {
+                pyproject: None,
+                project_root: None,
                line_length,
                exclude: vec![],
                extend_exclude: vec![],
                select: BTreeSet::from_iter(vec![CheckCode::E501]),
            };
-            check_lines(&mut checks, line, &settings);
+            check_lines(
+                &mut checks,
+                line,
+                &noqa_line_for,
+                &settings,
+                &fixer::Mode::Generate,
+            );
            return checks;
        };
        assert!(!check_with_max_line_length(6).is_empty());
--- a/src/checks.rs
+++ b/src/checks.rs
@@ -1,12 +1,10 @@
 use std::str::FromStr;

 use anyhow::Result;
-use once_cell::sync::Lazy;
-use regex::Regex;
 use rustpython_parser::ast::Location;
 use serde::{Deserialize, Serialize};

-pub const ALL_CHECK_CODES: [CheckCode; 42] = [
+pub const DEFAULT_CHECK_CODES: [CheckCode; 42] = [
    CheckCode::E402,
    CheckCode::E501,
    CheckCode::E711,
@@ -22,8 +20,10 @@ pub const ALL_CHECK_CODES: [CheckCode; 42] = [
    CheckCode::E902,
    CheckCode::E999,
    CheckCode::F401,
+    CheckCode::F402,
    CheckCode::F403,
    CheckCode::F404,
+    CheckCode::F405,
    CheckCode::F406,
    CheckCode::F407,
    CheckCode::F541,
@@ -47,6 +47,52 @@ pub const ALL_CHECK_CODES: [CheckCode; 42] = [
    CheckCode::F831,
    CheckCode::F841,
    CheckCode::F901,
+];
+
+pub const ALL_CHECK_CODES: [CheckCode; 45] = [
+    CheckCode::E402,
+    CheckCode::E501,
+    CheckCode::E711,
+    CheckCode::E712,
+    CheckCode::E713,
+    CheckCode::E714,
+    CheckCode::E721,
+    CheckCode::E722,
+    CheckCode::E731,
+    CheckCode::E741,
+    CheckCode::E742,
+    CheckCode::E743,
+    CheckCode::E902,
+    CheckCode::E999,
+    CheckCode::F401,
+    CheckCode::F402,
+    CheckCode::F403,
+    CheckCode::F404,
+    CheckCode::F405,
+    CheckCode::F406,
+    CheckCode::F407,
+    CheckCode::F541,
+    CheckCode::F601,
+    CheckCode::F602,
+    CheckCode::F621,
+    CheckCode::F622,
+    CheckCode::F631,
+    CheckCode::F632,
+    CheckCode::F633,
+    CheckCode::F634,
+    CheckCode::F701,
+    CheckCode::F702,
+    CheckCode::F704,
+    CheckCode::F706,
+    CheckCode::F707,
+    CheckCode::F722,
+    CheckCode::F821,
+    CheckCode::F822,
+    CheckCode::F823,
+    CheckCode::F831,
+    CheckCode::F841,
+    CheckCode::F901,
+    CheckCode::M001,
    CheckCode::R001,
    CheckCode::R002,
 ];
@@ -68,8 +114,10 @@ pub enum CheckCode {
    E902,
    E999,
    F401,
+    F402,
    F403,
    F404,
+    F405,
    F406,
    F407,
    F541,
@@ -95,6 +143,7 @@ pub enum CheckCode {
    F901,
    R001,
    R002,
+    M001,
 }

 impl FromStr for CheckCode {
@@ -117,8 +166,10 @@ impl FromStr for CheckCode {
            "E902" => Ok(CheckCode::E902),
            "E999" => Ok(CheckCode::E999),
            "F401" => Ok(CheckCode::F401),
+            "F402" => Ok(CheckCode::F402),
            "F403" => Ok(CheckCode::F403),
            "F404" => Ok(CheckCode::F404),
+            "F405" => Ok(CheckCode::F405),
            "F406" => Ok(CheckCode::F406),
            "F407" => Ok(CheckCode::F407),
            "F541" => Ok(CheckCode::F541),
@@ -144,6 +195,7 @@ impl FromStr for CheckCode {
            "F901" => Ok(CheckCode::F901),
            "R001" => Ok(CheckCode::R001),
            "R002" => Ok(CheckCode::R002),
+            "M001" => Ok(CheckCode::M001),
            _ => Err(anyhow::anyhow!("Unknown check code: {s}")),
        }
    }
@@ -167,8 +219,10 @@ impl CheckCode {
            CheckCode::E902 => "E902",
            CheckCode::E999 => "E999",
            CheckCode::F401 => "F401",
+            CheckCode::F402 => "F402",
            CheckCode::F403 => "F403",
            CheckCode::F404 => "F404",
+            CheckCode::F405 => "F405",
            CheckCode::F406 => "F406",
            CheckCode::F407 => "F407",
            CheckCode::F541 => "F541",
@@ -194,13 +248,14 @@ impl CheckCode {
            CheckCode::F901 => "F901",
            CheckCode::R001 => "R001",
            CheckCode::R002 => "R002",
+            CheckCode::M001 => "M001",
        }
    }

    /// The source for the check (either the AST, the filesystem, or the physical lines).
    pub fn lint_source(&self) -> &'static LintSource {
        match self {
-            CheckCode::E501 => &LintSource::Lines,
+            CheckCode::E501 | CheckCode::M001 => &LintSource::Lines,
            CheckCode::E902 | CheckCode::E999 => &LintSource::FileSystem,
            _ => &LintSource::AST,
        }
@@ -209,48 +264,51 @@ impl CheckCode {
    /// A placeholder representation of the CheckKind for the check.
    pub fn kind(&self) -> CheckKind {
        match self {
-            CheckCode::E742 => CheckKind::AmbiguousClassName("...".to_string()),
-            CheckCode::E743 => CheckKind::AmbiguousFunctionName("...".to_string()),
-            CheckCode::E741 => CheckKind::AmbiguousVariableName("...".to_string()),
-            CheckCode::F631 => CheckKind::AssertTuple,
-            CheckCode::F701 => CheckKind::BreakOutsideLoop,
-            CheckCode::F702 => CheckKind::ContinueOutsideLoop,
-            CheckCode::F707 => CheckKind::DefaultExceptNotLast,
-            CheckCode::E731 => CheckKind::DoNotAssignLambda,
-            CheckCode::E722 => CheckKind::DoNotUseBareExcept,
-            CheckCode::F831 => CheckKind::DuplicateArgumentName,
-            CheckCode::F541 => CheckKind::FStringMissingPlaceholders,
-            CheckCode::F722 => CheckKind::ForwardAnnotationSyntaxError("...".to_string()),
-            CheckCode::F407 => CheckKind::FutureFeatureNotDefined("...".to_string()),
-            CheckCode::E902 => CheckKind::IOError("...".to_string()),
-            CheckCode::F634 => CheckKind::IfTuple,
-            CheckCode::F406 => CheckKind::ImportStarNotPermitted("...".to_string()),
-            CheckCode::F403 => CheckKind::ImportStarUsage("...".to_string()),
-            CheckCode::F633 => CheckKind::InvalidPrintSyntax,
-            CheckCode::F632 => CheckKind::IsLiteral,
-            CheckCode::F404 => CheckKind::LateFutureImport,
-            CheckCode::E501 => CheckKind::LineTooLong(89, 88),
            CheckCode::E402 => CheckKind::ModuleImportNotAtTopOfFile,
-            CheckCode::F601 => CheckKind::MultiValueRepeatedKeyLiteral,
-            CheckCode::F602 => CheckKind::MultiValueRepeatedKeyVariable("...".to_string()),
-            CheckCode::R002 => CheckKind::NoAssertEquals,
+            CheckCode::E501 => CheckKind::LineTooLong(89, 88),
            CheckCode::E711 => CheckKind::NoneComparison(RejectedCmpop::Eq),
+            CheckCode::E712 => CheckKind::TrueFalseComparison(true, RejectedCmpop::Eq),
            CheckCode::E713 => CheckKind::NotInTest,
            CheckCode::E714 => CheckKind::NotIsTest,
-            CheckCode::F901 => CheckKind::RaiseNotImplemented,
-            CheckCode::F706 => CheckKind::ReturnOutsideFunction,
-            CheckCode::E999 => CheckKind::SyntaxError("...".to_string()),
-            CheckCode::F621 => CheckKind::TooManyExpressionsInStarredAssignment,
-            CheckCode::E712 => CheckKind::TrueFalseComparison(true, RejectedCmpop::Eq),
-            CheckCode::F622 => CheckKind::TwoStarredExpressions,
            CheckCode::E721 => CheckKind::TypeComparison,
+            CheckCode::E722 => CheckKind::DoNotUseBareExcept,
+            CheckCode::E731 => CheckKind::DoNotAssignLambda,
+            CheckCode::E741 => CheckKind::AmbiguousVariableName("...".to_string()),
+            CheckCode::E742 => CheckKind::AmbiguousClassName("...".to_string()),
+            CheckCode::E743 => CheckKind::AmbiguousFunctionName("...".to_string()),
+            CheckCode::E902 => CheckKind::IOError("...".to_string()),
+            CheckCode::E999 => CheckKind::SyntaxError("...".to_string()),
+            CheckCode::F401 => CheckKind::UnusedImport("...".to_string()),
+            CheckCode::F402 => CheckKind::ImportShadowedByLoopVar("...".to_string(), 1),
+            CheckCode::F403 => CheckKind::ImportStarUsed("...".to_string()),
+            CheckCode::F404 => CheckKind::LateFutureImport,
+            CheckCode::F405 => CheckKind::ImportStarUsage("...".to_string(), "...".to_string()),
+            CheckCode::F406 => CheckKind::ImportStarNotPermitted("...".to_string()),
+            CheckCode::F407 => CheckKind::FutureFeatureNotDefined("...".to_string()),
+            CheckCode::F541 => CheckKind::FStringMissingPlaceholders,
+            CheckCode::F601 => CheckKind::MultiValueRepeatedKeyLiteral,
+            CheckCode::F602 => CheckKind::MultiValueRepeatedKeyVariable("...".to_string()),
+            CheckCode::F621 => CheckKind::TooManyExpressionsInStarredAssignment,
+            CheckCode::F622 => CheckKind::TwoStarredExpressions,
+            CheckCode::F631 => CheckKind::AssertTuple,
+            CheckCode::F632 => CheckKind::IsLiteral,
+            CheckCode::F633 => CheckKind::InvalidPrintSyntax,
+            CheckCode::F634 => CheckKind::IfTuple,
+            CheckCode::F701 => CheckKind::BreakOutsideLoop,
+            CheckCode::F702 => CheckKind::ContinueOutsideLoop,
+            CheckCode::F704 => CheckKind::YieldOutsideFunction,
+            CheckCode::F706 => CheckKind::ReturnOutsideFunction,
+            CheckCode::F707 => CheckKind::DefaultExceptNotLast,
+            CheckCode::F722 => CheckKind::ForwardAnnotationSyntaxError("...".to_string()),
+            CheckCode::F821 => CheckKind::UndefinedName("...".to_string()),
            CheckCode::F822 => CheckKind::UndefinedExport("...".to_string()),
            CheckCode::F823 => CheckKind::UndefinedLocal("...".to_string()),
-            CheckCode::F821 => CheckKind::UndefinedName("...".to_string()),
-            CheckCode::F401 => CheckKind::UnusedImport("...".to_string()),
+            CheckCode::F831 => CheckKind::DuplicateArgumentName,
            CheckCode::F841 => CheckKind::UnusedVariable("...".to_string()),
+            CheckCode::F901 => CheckKind::RaiseNotImplemented,
+            CheckCode::M001 => CheckKind::UnusedNOQA(None),
            CheckCode::R001 => CheckKind::UselessObjectInheritance("...".to_string()),
-            CheckCode::F704 => CheckKind::YieldOutsideFunction,
+            CheckCode::R002 => CheckKind::NoAssertEquals,
        }
    }
 }
@@ -270,6 +328,7 @@ pub enum RejectedCmpop {

 #[derive(Debug, PartialEq, Eq, Serialize, Deserialize)]
 pub enum CheckKind {
+    UnusedNOQA(Option<String>),
    AmbiguousClassName(String),
    AmbiguousFunctionName(String),
    AmbiguousVariableName(String),
@@ -285,8 +344,10 @@ pub enum CheckKind {
    FutureFeatureNotDefined(String),
    IOError(String),
    IfTuple,
+    ImportShadowedByLoopVar(String, usize),
    ImportStarNotPermitted(String),
-    ImportStarUsage(String),
+    ImportStarUsage(String, String),
+    ImportStarUsed(String),
    InvalidPrintSyntax,
    IsLiteral,
    LateFutureImport,
@@ -333,8 +394,10 @@ impl CheckKind {
            CheckKind::FutureFeatureNotDefined(_) => "FutureFeatureNotDefined",
            CheckKind::IOError(_) => "IOError",
            CheckKind::IfTuple => "IfTuple",
+            CheckKind::ImportShadowedByLoopVar(_, _) => "ImportShadowedByLoopVar",
            CheckKind::ImportStarNotPermitted(_) => "ImportStarNotPermitted",
-            CheckKind::ImportStarUsage(_) => "ImportStarUsage",
+            CheckKind::ImportStarUsage(_, _) => "ImportStarUsage",
+            CheckKind::ImportStarUsed(_) => "ImportStarUsed",
            CheckKind::InvalidPrintSyntax => "InvalidPrintSyntax",
            CheckKind::IsLiteral => "IsLiteral",
            CheckKind::LateFutureImport => "LateFutureImport",
@@ -362,6 +425,7 @@ impl CheckKind {
            CheckKind::UnusedVariable(_) => "UnusedVariable",
            CheckKind::UselessObjectInheritance(_) => "UselessObjectInheritance",
            CheckKind::YieldOutsideFunction => "YieldOutsideFunction",
+            CheckKind::UnusedNOQA(_) => "UnusedNOQA",
        }
    }

@@ -383,8 +447,10 @@ impl CheckKind {
            CheckKind::FutureFeatureNotDefined(_) => &CheckCode::F407,
            CheckKind::IOError(_) => &CheckCode::E902,
            CheckKind::IfTuple => &CheckCode::F634,
+            CheckKind::ImportShadowedByLoopVar(_, _) => &CheckCode::F402,
            CheckKind::ImportStarNotPermitted(_) => &CheckCode::F406,
-            CheckKind::ImportStarUsage(_) => &CheckCode::F403,
+            CheckKind::ImportStarUsage(_, _) => &CheckCode::F405,
+            CheckKind::ImportStarUsed(_) => &CheckCode::F403,
            CheckKind::InvalidPrintSyntax => &CheckCode::F633,
            CheckKind::IsLiteral => &CheckCode::F632,
            CheckKind::LateFutureImport => &CheckCode::F404,
@@ -407,6 +473,7 @@ impl CheckKind {
            CheckKind::UndefinedLocal(_) => &CheckCode::F823,
            CheckKind::UndefinedName(_) => &CheckCode::F821,
            CheckKind::UnusedImport(_) => &CheckCode::F401,
+            CheckKind::UnusedNOQA(_) => &CheckCode::M001,
            CheckKind::UnusedVariable(_) => &CheckCode::F841,
            CheckKind::UselessObjectInheritance(_) => &CheckCode::R001,
            CheckKind::YieldOutsideFunction => &CheckCode::F704,
@@ -449,17 +516,21 @@ impl CheckKind {
            CheckKind::FutureFeatureNotDefined(name) => {
                format!("future feature '{name}' is not defined")
            }
-            CheckKind::IOError(name) => {
-                format!("No such file or directory: `{name}`")
-            }
+            CheckKind::IOError(message) => message.clone(),
            CheckKind::IfTuple => "If test is a tuple, which is always `True`".to_string(),
            CheckKind::InvalidPrintSyntax => "use of >> is invalid with print function".to_string(),
+            CheckKind::ImportShadowedByLoopVar(name, line) => {
+                format!("import '{name}' from line {line} shadowed by loop variable")
+            }
            CheckKind::ImportStarNotPermitted(name) => {
                format!("`from {name} import *` only allowed at module level")
            }
-            CheckKind::ImportStarUsage(name) => {
+            CheckKind::ImportStarUsed(name) => {
                format!("`from {name} import *` used; unable to detect undefined names")
            }
+            CheckKind::ImportStarUsage(name, sources) => {
+                format!("'{name}' may be undefined, or defined from star imports: {sources}")
+            }
            CheckKind::IsLiteral => "use ==/!= to compare constant literals".to_string(),
            CheckKind::LateFutureImport => {
                "from __future__ imports must occur at the beginning of the file".to_string()
@@ -536,6 +607,10 @@ impl CheckKind {
            CheckKind::YieldOutsideFunction => {
                "a `yield` or `yield from` statement outside of a function/method".to_string()
            }
+            CheckKind::UnusedNOQA(code) => match code {
+                None => "Unused `noqa` directive".to_string(),
+                Some(code) => format!("Unused `noqa` directive for: {code}"),
+            },
        }
    }

@@ -543,7 +618,9 @@ impl CheckKind {
    pub fn fixable(&self) -> bool {
        matches!(
            self,
-            CheckKind::NoAssertEquals | CheckKind::UselessObjectInheritance(_)
+            CheckKind::NoAssertEquals
+                | CheckKind::UselessObjectInheritance(_)
+                | CheckKind::UnusedNOQA(_)
        )
    }
 }
@@ -563,11 +640,6 @@ pub struct Check {
    pub fix: Option<Fix>,
 }

-static NO_QA_REGEX: Lazy<Regex> = Lazy::new(|| {
-    Regex::new(r"(?i)# noqa(?::\s?(?P<codes>([A-Z]+[0-9]+(?:[,\s]+)?)+))?").expect("Invalid regex")
-});
-static SPLIT_COMMA_REGEX: Lazy<Regex> = Lazy::new(|| Regex::new(r"[,\s]").expect("Invalid regex"));
-
 impl Check {
    pub fn new(kind: CheckKind, location: Location) -> Self {
        Self {
@@ -580,25 +652,4 @@ impl Check {
    pub fn amend(&mut self, fix: Fix) {
        self.fix = Some(fix);
    }
-
-    pub fn is_inline_ignored(&self, line: &str) -> bool {
-        match NO_QA_REGEX.captures(line) {
-            Some(caps) => match caps.name("codes") {
-                Some(codes) => {
-                    for code in SPLIT_COMMA_REGEX
-                        .split(codes.as_str())
-                        .map(|code| code.trim())
-                        .filter(|code| !code.is_empty())
-                    {
-                        if code == self.kind.code().as_str() {
-                            return true;
-                        }
-                    }
-                    false
-                }
-                None => true,
-            },
-            None => false,
-        }
-    }
 }
--- a/src/fs.rs
+++ b/src/fs.rs
@@ -59,14 +59,14 @@ pub fn iter_python_files<'a>(
    path: &'a Path,
    exclude: &'a [FilePattern],
    extend_exclude: &'a [FilePattern],
-) -> impl Iterator<Item = DirEntry> + 'a {
+) -> impl Iterator<Item = Result<DirEntry, walkdir::Error>> + 'a {
    // Run some checks over the provided patterns, to enable optimizations below.
    let has_exclude = !exclude.is_empty();
    let has_extend_exclude = !extend_exclude.is_empty();
    let exclude_simple = exclude
        .iter()
        .all(|pattern| matches!(pattern, FilePattern::Simple(_)));
-    let extend_exclude_simple = exclude
+    let extend_exclude_simple = extend_exclude
        .iter()
        .all(|pattern| matches!(pattern, FilePattern::Simple(_)));

@@ -105,18 +105,15 @@ pub fn iter_python_files<'a>(
                }
            }
        })
-        .filter_map(|entry| entry.ok())
        .filter(|entry| {
-            let path = entry.path();
-            is_included(path)
+            entry.as_ref().map_or(true, |entry| {
+                (entry.depth() == 0 && !entry.file_type().is_dir()) || is_included(entry.path())
+            })
        })
 }

 /// Convert any path to an absolute path (based on the current working directory).
 pub fn normalize_path(path: &Path) -> PathBuf {
-    if path == Path::new(".") || path == Path::new("..") {
-        return path.to_path_buf();
-    }
    if let Ok(path) = path.absolutize() {
        return path.to_path_buf();
    }
@@ -125,9 +122,6 @@ pub fn normalize_path(path: &Path) -> PathBuf {

 /// Convert any path to an absolute path (based on the specified project root).
 pub fn normalize_path_to(path: &Path, project_root: &Path) -> PathBuf {
-    if path == Path::new(".") || path == Path::new("..") {
-        return path.to_path_buf();
-    }
    if let Ok(path) = path.absolutize_from(project_root) {
        return path.to_path_buf();
    }
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -10,6 +10,7 @@ pub mod fs;
 pub mod linter;
 pub mod logging;
 pub mod message;
+mod noqa;
 pub mod printer;
 pub mod pyproject;
 mod python;
--- a/src/linter.rs
+++ b/src/linter.rs
@@ -2,40 +2,57 @@ use std::path::Path;

 use anyhow::Result;
 use log::debug;
-use rustpython_parser::parser;
+use rustpython_parser::lexer::LexResult;
+use rustpython_parser::{lexer, parser};

 use crate::autofix::fixer;
 use crate::autofix::fixer::fix_file;
 use crate::check_ast::check_ast;
 use crate::check_lines::check_lines;
-use crate::checks::{Check, LintSource};
+use crate::checks::{Check, CheckCode, CheckKind, LintSource};
 use crate::message::Message;
+use crate::noqa::add_noqa;
 use crate::settings::Settings;
-use crate::{cache, fs};
+use crate::{cache, fs, noqa};

 fn check_path(
    path: &Path,
    contents: &str,
+    tokens: Vec<LexResult>,
    settings: &Settings,
    autofix: &fixer::Mode,
-) -> Result<Vec<Check>> {
+) -> Vec<Check> {
    // Aggregate all checks.
    let mut checks: Vec<Check> = vec![];

+    // Determine the noqa line for every line in the source.
+    let noqa_line_for = noqa::extract_noqa_line_for(&tokens);
+
    // Run the AST-based checks.
    if settings
        .select
        .iter()
        .any(|check_code| matches!(check_code.lint_source(), LintSource::AST))
    {
-        let python_ast = parser::parse_program(contents, "<filename>")?;
-        checks.extend(check_ast(&python_ast, contents, settings, autofix, path));
+        match parser::parse_program_tokens(tokens, "<filename>") {
+            Ok(python_ast) => {
+                checks.extend(check_ast(&python_ast, contents, settings, autofix, path))
+            }
+            Err(parse_error) => {
+                if settings.select.contains(&CheckCode::E999) {
+                    checks.push(Check::new(
+                        CheckKind::SyntaxError(parse_error.error.to_string()),
+                        parse_error.location,
+                    ))
+                }
+            }
+        }
    }

    // Run the lines-based checks.
-    check_lines(&mut checks, contents, settings);
+    check_lines(&mut checks, contents, &noqa_line_for, settings, autofix);

-    Ok(checks)
+    checks
 }

 pub fn lint_path(
@@ -55,8 +72,11 @@ pub fn lint_path(
    // Read the file from disk.
    let contents = fs::read_file(path)?;

+    // Tokenize once.
+    let tokens: Vec<LexResult> = lexer::make_tokenizer(&contents).collect();
+
    // Generate checks.
-    let mut checks = check_path(path, &contents, settings, autofix)?;
+    let mut checks = check_path(path, &contents, tokens, settings, autofix);

    // Apply autofix.
    if matches!(autofix, fixer::Mode::Apply) {
@@ -78,12 +98,29 @@ pub fn lint_path(
    Ok(messages)
 }

+pub fn add_noqa_to_path(path: &Path, settings: &Settings) -> Result<usize> {
+    // Read the file from disk.
+    let contents = fs::read_file(path)?;
+
+    // Tokenize once.
+    let tokens: Vec<LexResult> = lexer::make_tokenizer(&contents).collect();
+
+    // Determine the noqa line for every line in the source.
+    let noqa_line_for = noqa::extract_noqa_line_for(&tokens);
+
+    // Generate checks.
+    let checks = check_path(path, &contents, tokens, settings, &fixer::Mode::None);
+
+    add_noqa(&checks, &contents, &noqa_line_for, path)
+}
+
 #[cfg(test)]
 mod tests {
-    use std::collections::BTreeSet;
    use std::path::Path;

    use anyhow::Result;
+    use rustpython_parser::lexer;
+    use rustpython_parser::lexer::LexResult;

    use crate::autofix::fixer;
    use crate::checks::{Check, CheckCode};
@@ -97,19 +134,17 @@ mod tests {
        autofix: &fixer::Mode,
    ) -> Result<Vec<Check>> {
        let contents = fs::read_file(path)?;
-        linter::check_path(path, &contents, settings, autofix)
+        let tokens: Vec<LexResult> = lexer::make_tokenizer(&contents).collect();
+        Ok(linter::check_path(
+            path, &contents, tokens, settings, autofix,
+        ))
    }

    #[test]
    fn e402() -> Result<()> {
        let mut checks = check_path(
            Path::new("./resources/test/fixtures/E402.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::E402]),
-            },
+            &settings::Settings::for_rule(CheckCode::E402),
            &fixer::Mode::Generate,
        )?;
        checks.sort_by_key(|check| check.location);
@@ -121,12 +156,7 @@ mod tests {
    fn e501() -> Result<()> {
        let mut checks = check_path(
            Path::new("./resources/test/fixtures/E501.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::E501]),
-            },
+            &settings::Settings::for_rule(CheckCode::E501),
            &fixer::Mode::Generate,
        )?;
        checks.sort_by_key(|check| check.location);
@@ -138,12 +168,7 @@ mod tests {
    fn e711() -> Result<()> {
        let mut checks = check_path(
            Path::new("./resources/test/fixtures/E711.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::E711]),
-            },
+            &settings::Settings::for_rule(CheckCode::E711),
            &fixer::Mode::Generate,
        )?;
        checks.sort_by_key(|check| check.location);
@@ -155,12 +180,7 @@ mod tests {
    fn e712() -> Result<()> {
        let mut checks = check_path(
            Path::new("./resources/test/fixtures/E712.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::E712]),
-            },
+            &settings::Settings::for_rule(CheckCode::E712),
            &fixer::Mode::Generate,
        )?;
        checks.sort_by_key(|check| check.location);
@@ -172,12 +192,7 @@ mod tests {
    fn e713() -> Result<()> {
        let mut checks = check_path(
            Path::new("./resources/test/fixtures/E713.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::E713]),
-            },
+            &settings::Settings::for_rule(CheckCode::E713),
            &fixer::Mode::Generate,
        )?;
        checks.sort_by_key(|check| check.location);
@@ -189,12 +204,7 @@ mod tests {
    fn e721() -> Result<()> {
        let mut checks = check_path(
            Path::new("./resources/test/fixtures/E721.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::E721]),
-            },
+            &settings::Settings::for_rule(CheckCode::E721),
            &fixer::Mode::Generate,
        )?;
        checks.sort_by_key(|check| check.location);
@@ -206,12 +216,7 @@ mod tests {
    fn e722() -> Result<()> {
        let mut checks = check_path(
            Path::new("./resources/test/fixtures/E722.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::E722]),
-            },
+            &settings::Settings::for_rule(CheckCode::E722),
            &fixer::Mode::Generate,
        )?;
        checks.sort_by_key(|check| check.location);
@@ -223,12 +228,7 @@ mod tests {
    fn e714() -> Result<()> {
        let mut checks = check_path(
            Path::new("./resources/test/fixtures/E714.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::E714]),
-            },
+            &settings::Settings::for_rule(CheckCode::E714),
            &fixer::Mode::Generate,
        )?;
        checks.sort_by_key(|check| check.location);
@@ -240,12 +240,7 @@ mod tests {
    fn e731() -> Result<()> {
        let mut checks = check_path(
            Path::new("./resources/test/fixtures/E731.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::E731]),
-            },
+            &settings::Settings::for_rule(CheckCode::E731),
            &fixer::Mode::Generate,
        )?;
        checks.sort_by_key(|check| check.location);
@@ -257,12 +252,7 @@ mod tests {
    fn e741() -> Result<()> {
        let mut checks = check_path(
            Path::new("./resources/test/fixtures/E741.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::E741]),
-            },
+            &settings::Settings::for_rule(CheckCode::E741),
            &fixer::Mode::Generate,
        )?;
        checks.sort_by_key(|check| check.location);
@@ -274,12 +264,7 @@ mod tests {
    fn e742() -> Result<()> {
        let mut checks = check_path(
            Path::new("./resources/test/fixtures/E742.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::E742]),
-            },
+            &settings::Settings::for_rule(CheckCode::E742),
            &fixer::Mode::Generate,
        )?;
        checks.sort_by_key(|check| check.location);
@@ -291,12 +276,7 @@ mod tests {
    fn e743() -> Result<()> {
        let mut checks = check_path(
            Path::new("./resources/test/fixtures/E743.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::E743]),
-            },
+            &settings::Settings::for_rule(CheckCode::E743),
            &fixer::Mode::Generate,
        )?;
        checks.sort_by_key(|check| check.location);
@@ -308,12 +288,19 @@ mod tests {
    fn f401() -> Result<()> {
        let mut checks = check_path(
            Path::new("./resources/test/fixtures/F401.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F401]),
-            },
+            &settings::Settings::for_rule(CheckCode::F401),
+            &fixer::Mode::Generate,
+        )?;
+        checks.sort_by_key(|check| check.location);
+        insta::assert_yaml_snapshot!(checks);
+        Ok(())
+    }
+
+    #[test]
+    fn f402() -> Result<()> {
+        let mut checks = check_path(
+            Path::new("./resources/test/fixtures/F402.py"),
+            &settings::Settings::for_rule(CheckCode::F402),
            &fixer::Mode::Generate,
        )?;
        checks.sort_by_key(|check| check.location);
@@ -325,12 +312,7 @@ mod tests {
    fn f403() -> Result<()> {
        let mut checks = check_path(
            Path::new("./resources/test/fixtures/F403.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F403]),
-            },
+            &settings::Settings::for_rule(CheckCode::F403),
            &fixer::Mode::Generate,
        )?;
        checks.sort_by_key(|check| check.location);
@@ -342,12 +324,19 @@ mod tests {
    fn f404() -> Result<()> {
        let mut checks = check_path(
            Path::new("./resources/test/fixtures/F404.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F404]),
-            },
+            &settings::Settings::for_rule(CheckCode::F404),
+            &fixer::Mode::Generate,
+        )?;
+        checks.sort_by_key(|check| check.location);
+        insta::assert_yaml_snapshot!(checks);
+        Ok(())
+    }
+
+    #[test]
+    fn f405() -> Result<()> {
+        let mut checks = check_path(
+            Path::new("./resources/test/fixtures/F405.py"),
+            &settings::Settings::for_rule(CheckCode::F405),
            &fixer::Mode::Generate,
        )?;
        checks.sort_by_key(|check| check.location);
@@ -359,12 +348,7 @@ mod tests {
    fn f406() -> Result<()> {
        let mut checks = check_path(
            Path::new("./resources/test/fixtures/F406.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F406]),
-            },
+            &settings::Settings::for_rule(CheckCode::F406),
            &fixer::Mode::Generate,
        )?;
        checks.sort_by_key(|check| check.location);
@@ -376,12 +360,7 @@ mod tests {
    fn f407() -> Result<()> {
        let mut checks = check_path(
            Path::new("./resources/test/fixtures/F407.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F407]),
-            },
+            &settings::Settings::for_rule(CheckCode::F407),
            &fixer::Mode::Generate,
        )?;
        checks.sort_by_key(|check| check.location);
@@ -393,12 +372,7 @@ mod tests {
    fn f541() -> Result<()> {
        let mut checks = check_path(
            Path::new("./resources/test/fixtures/F541.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F541]),
-            },
+            &settings::Settings::for_rule(CheckCode::F541),
            &fixer::Mode::Generate,
        )?;
        checks.sort_by_key(|check| check.location);
@@ -410,12 +384,7 @@ mod tests {
    fn f601() -> Result<()> {
        let mut checks = check_path(
            Path::new("./resources/test/fixtures/F601.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F601]),
-            },
+            &settings::Settings::for_rule(CheckCode::F601),
            &fixer::Mode::Generate,
        )?;
        checks.sort_by_key(|check| check.location);
@@ -427,12 +396,7 @@ mod tests {
    fn f602() -> Result<()> {
        let mut checks = check_path(
            Path::new("./resources/test/fixtures/F602.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F602]),
-            },
+            &settings::Settings::for_rule(CheckCode::F602),
            &fixer::Mode::Generate,
        )?;
        checks.sort_by_key(|check| check.location);
@@ -444,12 +408,7 @@ mod tests {
    fn f622() -> Result<()> {
        let mut checks = check_path(
            Path::new("./resources/test/fixtures/F622.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F622]),
-            },
+            &settings::Settings::for_rule(CheckCode::F622),
            &fixer::Mode::Generate,
        )?;
        checks.sort_by_key(|check| check.location);
@@ -461,12 +420,7 @@ mod tests {
    fn f631() -> Result<()> {
        let mut checks = check_path(
            Path::new("./resources/test/fixtures/F631.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F631]),
-            },
+            &settings::Settings::for_rule(CheckCode::F631),
            &fixer::Mode::Generate,
        )?;
        checks.sort_by_key(|check| check.location);
@@ -478,12 +432,7 @@ mod tests {
    fn f632() -> Result<()> {
        let mut checks = check_path(
            Path::new("./resources/test/fixtures/F632.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F632]),
-            },
+            &settings::Settings::for_rule(CheckCode::F632),
            &fixer::Mode::Generate,
        )?;
        checks.sort_by_key(|check| check.location);
@@ -495,12 +444,7 @@ mod tests {
    fn f633() -> Result<()> {
        let mut checks = check_path(
            Path::new("./resources/test/fixtures/F633.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F633]),
-            },
+            &settings::Settings::for_rule(CheckCode::F633),
            &fixer::Mode::Generate,
        )?;
        checks.sort_by_key(|check| check.location);
@@ -512,12 +456,7 @@ mod tests {
    fn f634() -> Result<()> {
        let mut checks = check_path(
            Path::new("./resources/test/fixtures/F634.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F634]),
-            },
+            &settings::Settings::for_rule(CheckCode::F634),
            &fixer::Mode::Generate,
        )?;
        checks.sort_by_key(|check| check.location);
@@ -529,12 +468,7 @@ mod tests {
    fn f701() -> Result<()> {
        let mut checks = check_path(
            Path::new("./resources/test/fixtures/F701.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F701]),
-            },
+            &settings::Settings::for_rule(CheckCode::F701),
            &fixer::Mode::Generate,
        )?;
        checks.sort_by_key(|check| check.location);
@@ -546,12 +480,7 @@ mod tests {
    fn f702() -> Result<()> {
        let mut checks = check_path(
            Path::new("./resources/test/fixtures/F702.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F702]),
-            },
+            &settings::Settings::for_rule(CheckCode::F702),
            &fixer::Mode::Generate,
        )?;
        checks.sort_by_key(|check| check.location);
@@ -563,12 +492,7 @@ mod tests {
    fn f704() -> Result<()> {
        let mut checks = check_path(
            Path::new("./resources/test/fixtures/F704.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F704]),
-            },
+            &settings::Settings::for_rule(CheckCode::F704),
            &fixer::Mode::Generate,
        )?;
        checks.sort_by_key(|check| check.location);
@@ -580,12 +504,7 @@ mod tests {
    fn f706() -> Result<()> {
        let mut checks = check_path(
            Path::new("./resources/test/fixtures/F706.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F706]),
-            },
+            &settings::Settings::for_rule(CheckCode::F706),
            &fixer::Mode::Generate,
        )?;
        checks.sort_by_key(|check| check.location);
@@ -597,12 +516,7 @@ mod tests {
    fn f707() -> Result<()> {
        let mut checks = check_path(
            Path::new("./resources/test/fixtures/F707.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F707]),
-            },
+            &settings::Settings::for_rule(CheckCode::F707),
            &fixer::Mode::Generate,
        )?;
        checks.sort_by_key(|check| check.location);
@@ -614,12 +528,7 @@ mod tests {
    fn f722() -> Result<()> {
        let mut checks = check_path(
            Path::new("./resources/test/fixtures/F722.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F722]),
-            },
+            &settings::Settings::for_rule(CheckCode::F722),
            &fixer::Mode::Generate,
        )?;
        checks.sort_by_key(|check| check.location);
@@ -631,12 +540,7 @@ mod tests {
    fn f821() -> Result<()> {
        let mut checks = check_path(
            Path::new("./resources/test/fixtures/F821.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F821]),
-            },
+            &settings::Settings::for_rule(CheckCode::F821),
            &fixer::Mode::Generate,
        )?;
        checks.sort_by_key(|check| check.location);
@@ -648,12 +552,7 @@ mod tests {
    fn f822() -> Result<()> {
        let mut checks = check_path(
            Path::new("./resources/test/fixtures/F822.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F822]),
-            },
+            &settings::Settings::for_rule(CheckCode::F822),
            &fixer::Mode::Generate,
        )?;
        checks.sort_by_key(|check| check.location);
@@ -665,12 +564,7 @@ mod tests {
    fn f823() -> Result<()> {
        let mut checks = check_path(
            Path::new("./resources/test/fixtures/F823.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F823]),
-            },
+            &settings::Settings::for_rule(CheckCode::F823),
            &fixer::Mode::Generate,
        )?;
        checks.sort_by_key(|check| check.location);
@@ -682,12 +576,7 @@ mod tests {
    fn f831() -> Result<()> {
        let mut checks = check_path(
            Path::new("./resources/test/fixtures/F831.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F831]),
-            },
+            &settings::Settings::for_rule(CheckCode::F831),
            &fixer::Mode::Generate,
        )?;
        checks.sort_by_key(|check| check.location);
@@ -699,12 +588,7 @@ mod tests {
    fn f841() -> Result<()> {
        let mut checks = check_path(
            Path::new("./resources/test/fixtures/F841.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F841]),
-            },
+            &settings::Settings::for_rule(CheckCode::F841),
            &fixer::Mode::Generate,
        )?;
        checks.sort_by_key(|check| check.location);
@@ -716,12 +600,19 @@ mod tests {
    fn f901() -> Result<()> {
        let mut checks = check_path(
            Path::new("./resources/test/fixtures/F901.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F901]),
-            },
+            &settings::Settings::for_rule(CheckCode::F901),
+            &fixer::Mode::Generate,
+        )?;
+        checks.sort_by_key(|check| check.location);
+        insta::assert_yaml_snapshot!(checks);
+        Ok(())
+    }
+
+    #[test]
+    fn m001() -> Result<()> {
+        let mut checks = check_path(
+            Path::new("./resources/test/fixtures/M001.py"),
+            &settings::Settings::for_rules(vec![CheckCode::M001, CheckCode::E501, CheckCode::F841]),
            &fixer::Mode::Generate,
        )?;
        checks.sort_by_key(|check| check.location);
@@ -733,12 +624,7 @@ mod tests {
    fn r001() -> Result<()> {
        let mut checks = check_path(
            Path::new("./resources/test/fixtures/R001.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::R001]),
-            },
+            &settings::Settings::for_rule(CheckCode::R001),
            &fixer::Mode::Generate,
        )?;
        checks.sort_by_key(|check| check.location);
@@ -750,12 +636,7 @@ mod tests {
    fn r002() -> Result<()> {
        let mut checks = check_path(
            Path::new("./resources/test/fixtures/R002.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::R002]),
-            },
+            &settings::Settings::for_rule(CheckCode::R002),
            &fixer::Mode::Generate,
        )?;
        checks.sort_by_key(|check| check.location);
@@ -767,12 +648,7 @@ mod tests {
    fn init() -> Result<()> {
        let mut checks = check_path(
            Path::new("./resources/test/fixtures/__init__.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F821, CheckCode::F822]),
-            },
+            &settings::Settings::for_rules(vec![CheckCode::F821, CheckCode::F822]),
            &fixer::Mode::Generate,
        )?;
        checks.sort_by_key(|check| check.location);
@@ -784,12 +660,7 @@ mod tests {
    fn future_annotations() -> Result<()> {
        let mut checks = check_path(
            Path::new("./resources/test/fixtures/future_annotations.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F401, CheckCode::F821]),
-            },
+            &settings::Settings::for_rules(vec![CheckCode::F401, CheckCode::F821]),
            &fixer::Mode::Generate,
        )?;
        checks.sort_by_key(|check| check.location);
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,6 +1,7 @@
 extern crate core;

-use std::path::PathBuf;
+use std::io;
+use std::path::{Path, PathBuf};
 use std::process::ExitCode;
 use std::sync::mpsc::channel;
 use std::time::Instant;
@@ -24,6 +25,7 @@ use ::ruff::printer::{Printer, SerializationFormat};
 use ::ruff::pyproject;
 use ::ruff::settings::{FilePattern, Settings};
 use ::ruff::tell_user;
+use ruff::linter::add_noqa_to_path;

 const CARGO_PKG_NAME: &str = env!("CARGO_PKG_NAME");
 const CARGO_PKG_VERSION: &str = env!("CARGO_PKG_VERSION");
@@ -56,9 +58,15 @@ struct Cli {
    /// List of error codes to enable.
    #[clap(long, multiple = true)]
    select: Vec<CheckCode>,
+    /// Like --select, but adds additional error codes on top of the selected ones.
+    #[clap(long, multiple = true)]
+    extend_select: Vec<CheckCode>,
    /// List of error codes to ignore.
    #[clap(long, multiple = true)]
    ignore: Vec<CheckCode>,
+    /// Like --ignore, but adds additional error codes on top of the ignored ones.
+    #[clap(long, multiple = true)]
+    extend_ignore: Vec<CheckCode>,
    /// List of paths, used to exclude files and/or directories from checks.
    #[clap(long, multiple = true)]
    exclude: Vec<String>,
@@ -68,6 +76,15 @@ struct Cli {
    /// Output serialization format for error messages.
    #[clap(long, arg_enum, default_value_t=SerializationFormat::Text)]
    format: SerializationFormat,
+    /// See the files ruff will be run against with the current settings.
+    #[clap(long, action)]
+    show_files: bool,
+    /// See ruff's settings.
+    #[clap(long, action)]
+    show_settings: bool,
+    /// Enable automatic additions of noqa directives to failing lines.
+    #[clap(long, action)]
+    add_noqa: bool,
 }

 #[cfg(feature = "update-informer")]
@@ -94,6 +111,22 @@ fn check_for_updates() {
    }
 }

+fn show_settings(settings: &Settings) {
+    println!("{:#?}", settings);
+}
+
+fn show_files(files: &[PathBuf], settings: &Settings) {
+    let mut entries: Vec<DirEntry> = files
+        .iter()
+        .flat_map(|path| iter_python_files(path, &settings.exclude, &settings.extend_exclude))
+        .flatten()
+        .collect();
+    entries.sort_by(|a, b| a.path().cmp(b.path()));
+    for entry in entries {
+        println!("{}", entry.path().to_string_lossy());
+    }
+}
+
 fn run_once(
    files: &[PathBuf],
    settings: &Settings,
@@ -102,7 +135,7 @@ fn run_once(
 ) -> Result<Vec<Message>> {
    // Collect all the files to check.
    let start = Instant::now();
-    let paths: Vec<DirEntry> = files
+    let paths: Vec<Result<DirEntry, walkdir::Error>> = files
        .iter()
        .flat_map(|path| iter_python_files(path, &settings.exclude, &settings.extend_exclude))
        .collect();
@@ -113,16 +146,33 @@ fn run_once(
    let mut messages: Vec<Message> = paths
        .par_iter()
        .map(|entry| {
-            lint_path(entry.path(), settings, &cache.into(), &autofix.into()).unwrap_or_else(|e| {
-                if settings.select.contains(&CheckCode::E999) {
-                    vec![Message {
-                        kind: CheckKind::SyntaxError(e.to_string()),
-                        fixed: false,
-                        location: Default::default(),
-                        filename: entry.path().to_string_lossy().to_string(),
-                    }]
+            match entry {
+                Ok(entry) => {
+                    let path = entry.path();
+                    lint_path(path, settings, &cache.into(), &autofix.into())
+                        .map_err(|e| (Some(path.to_owned()), e.to_string()))
+                }
+                Err(e) => Err((
+                    e.path().map(Path::to_owned),
+                    e.io_error()
+                        .map_or_else(|| e.to_string(), io::Error::to_string),
+                )),
+            }
+            .unwrap_or_else(|(path, message)| {
+                if let Some(path) = path {
+                    if settings.select.contains(&CheckCode::E902) {
+                        vec![Message {
+                            kind: CheckKind::IOError(message),
+                            fixed: false,
+                            location: Default::default(),
+                            filename: path.to_string_lossy().to_string(),
+                        }]
+                    } else {
+                        error!("Failed to check {}: {message}", path.to_string_lossy());
+                        vec![]
+                    }
                } else {
-                    error!("Failed to check {}: {e:?}", entry.path().to_string_lossy());
+                    error!("{message}");
                    vec![]
                }
            })
@@ -130,19 +180,6 @@ fn run_once(
        .flatten()
        .collect();

-    if settings.select.contains(&CheckCode::E902) {
-        for file in files {
-            if !file.exists() {
-                messages.push(Message {
-                    kind: CheckKind::IOError(file.to_string_lossy().to_string()),
-                    fixed: false,
-                    location: Default::default(),
-                    filename: file.to_string_lossy().to_string(),
-                })
-            }
-        }
-    }
-
    messages.sort_unstable();
    let duration = start.elapsed();
    debug!("Checked files in: {:?}", duration);
@@ -150,6 +187,35 @@ fn run_once(
    Ok(messages)
 }

+fn add_noqa(files: &[PathBuf], settings: &Settings) -> Result<usize> {
+    // Collect all the files to check.
+    let start = Instant::now();
+    let paths: Vec<Result<DirEntry, walkdir::Error>> = files
+        .iter()
+        .flat_map(|path| iter_python_files(path, &settings.exclude, &settings.extend_exclude))
+        .collect();
+    let duration = start.elapsed();
+    debug!("Identified files to lint in: {:?}", duration);
+
+    let start = Instant::now();
+    let modifications: usize = paths
+        .par_iter()
+        .map(|entry| match entry {
+            Ok(entry) => {
+                let path = entry.path();
+                add_noqa_to_path(path, settings)
+            }
+            Err(_) => Ok(0),
+        })
+        .flatten()
+        .sum();
+
+    let duration = start.elapsed();
+    debug!("Added noqa to files in: {:?}", duration);
+
+    Ok(modifications)
+}
+
 fn inner_main() -> Result<ExitCode> {
    let cli = Cli::parse();

@@ -168,36 +234,63 @@ fn inner_main() -> Result<ExitCode> {
    };

    // Parse the settings from the pyproject.toml and command-line arguments.
-    let mut settings = Settings::from_pyproject(&pyproject, &project_root);
+    let exclude: Vec<FilePattern> = cli
+        .exclude
+        .iter()
+        .map(|path| FilePattern::from_user(path, &project_root))
+        .collect();
+    let extend_exclude: Vec<FilePattern> = cli
+        .extend_exclude
+        .iter()
+        .map(|path| FilePattern::from_user(path, &project_root))
+        .collect();
+
+    let mut settings = Settings::from_pyproject(pyproject, project_root);
+    if !exclude.is_empty() {
+        settings.exclude = exclude;
+    }
+    if !extend_exclude.is_empty() {
+        settings.extend_exclude = extend_exclude;
+    }
    if !cli.select.is_empty() {
+        settings.clear();
        settings.select(cli.select);
    }
+    if !cli.extend_select.is_empty() {
+        settings.select(cli.extend_select);
+    }
    if !cli.ignore.is_empty() {
        settings.ignore(&cli.ignore);
    }
-    if !cli.exclude.is_empty() {
-        settings.exclude = cli
-            .exclude
-            .iter()
-            .map(|path| FilePattern::from_user(path, &project_root))
-            .collect();
+    if !cli.extend_ignore.is_empty() {
+        settings.ignore(&cli.extend_ignore);
    }
-    if !cli.extend_exclude.is_empty() {
-        settings.extend_exclude = cli
-            .extend_exclude
-            .iter()
-            .map(|path| FilePattern::from_user(path, &project_root))
-            .collect();
+
+    if cli.show_settings && cli.show_files {
+        println!("Error: specify --show-settings or show-files (not both).");
+        return Ok(ExitCode::FAILURE);
+    }
+    if cli.show_settings {
+        show_settings(&settings);
+        return Ok(ExitCode::SUCCESS);
+    }
+    if cli.show_files {
+        show_files(&cli.files, &settings);
+        return Ok(ExitCode::SUCCESS);
    }

    cache::init()?;

-    let mut printer = Printer::new(cli.format);
+    let mut printer = Printer::new(cli.format, cli.verbose);
    if cli.watch {
        if cli.fix {
            println!("Warning: --fix is not enabled in watch mode.");
        }

+        if cli.add_noqa {
+            println!("Warning: --no-qa is not enabled in watch mode.");
+        }
+
        if cli.format != SerializationFormat::Text {
            println!("Warning: --format 'text' is used in watch mode.");
        }
@@ -236,6 +329,11 @@ fn inner_main() -> Result<ExitCode> {
                Err(e) => return Err(e.into()),
            }
        }
+    } else if cli.add_noqa {
+        let modifications = add_noqa(&cli.files, &settings)?;
+        if modifications > 0 {
+            println!("Added {modifications} noqa directives.");
+        }
    } else {
        let messages = run_once(&cli.files, &settings, !cli.no_cache, cli.fix)?;
        if !cli.quiet {
--- a/src/noqa.rs
+++ b/src/noqa.rs
@@ -0,0 +1,280 @@
+use std::cmp::{max, min};
+
+use crate::checks::{Check, CheckCode};
+use anyhow::Result;
+use once_cell::sync::Lazy;
+use regex::Regex;
+use rustpython_parser::lexer::{LexResult, Tok};
+use std::collections::{BTreeMap, BTreeSet};
+use std::fs;
+use std::path::Path;
+
+static NO_QA_REGEX: Lazy<Regex> = Lazy::new(|| {
+    Regex::new(r"(?i)(?P<noqa>\s*# noqa(?::\s?(?P<codes>([A-Z]+[0-9]+(?:[,\s]+)?)+))?)")
+        .expect("Invalid regex")
+});
+static SPLIT_COMMA_REGEX: Lazy<Regex> = Lazy::new(|| Regex::new(r"[,\s]").expect("Invalid regex"));
+
+#[derive(Debug)]
+pub enum Directive<'a> {
+    None,
+    All(usize),
+    Codes(usize, Vec<&'a str>),
+}
+
+pub fn extract_noqa_directive(line: &str) -> Directive {
+    match NO_QA_REGEX.captures(line) {
+        Some(caps) => match caps.name("noqa") {
+            Some(noqa) => match caps.name("codes") {
+                Some(codes) => Directive::Codes(
+                    noqa.start(),
+                    SPLIT_COMMA_REGEX
+                        .split(codes.as_str())
+                        .map(|code| code.trim())
+                        .filter(|code| !code.is_empty())
+                        .collect(),
+                ),
+                None => Directive::All(noqa.start()),
+            },
+            None => Directive::None,
+        },
+        None => Directive::None,
+    }
+}
+
+pub fn extract_noqa_line_for(lxr: &[LexResult]) -> Vec<usize> {
+    let mut noqa_line_for: Vec<usize> = vec![];
+
+    let mut last_is_string = false;
+    let mut last_seen = usize::MIN;
+    let mut min_line = usize::MAX;
+    let mut max_line = usize::MIN;
+
+    for (start, tok, end) in lxr.iter().flatten() {
+        if matches!(tok, Tok::EndOfFile) {
+            break;
+        }
+
+        if matches!(tok, Tok::Newline) {
+            min_line = min(min_line, start.row());
+            max_line = max(max_line, start.row());
+
+            // For now, we only care about preserving noqa directives across multi-line strings.
+            if last_is_string {
+                noqa_line_for.extend(vec![max_line; (max_line + 1) - min_line]);
+            } else {
+                for i in (min_line - 1)..(max_line) {
+                    noqa_line_for.push(i + 1);
+                }
+            }
+
+            min_line = usize::MAX;
+            max_line = usize::MIN;
+        } else {
+            // Handle empty lines.
+            if start.row() > last_seen {
+                for i in last_seen..(start.row() - 1) {
+                    noqa_line_for.push(i + 1);
+                }
+            }
+
+            min_line = min(min_line, start.row());
+            max_line = max(max_line, end.row());
+        }
+        last_seen = start.row();
+        last_is_string = matches!(tok, Tok::String { .. });
+    }
+
+    noqa_line_for
+}
+
+fn add_noqa_inner(
+    checks: &Vec<Check>,
+    contents: &str,
+    noqa_line_for: &[usize],
+) -> Result<(usize, String)> {
+    let lines: Vec<&str> = contents.lines().collect();
+    let mut matches_by_line: BTreeMap<usize, BTreeSet<&CheckCode>> = BTreeMap::new();
+    for lineno in 0..lines.len() {
+        let mut codes: BTreeSet<&CheckCode> = BTreeSet::new();
+        for check in checks {
+            if check.location.row() == lineno + 1 {
+                codes.insert(check.kind.code());
+            }
+        }
+
+        // Grab the noqa (logical) line number for the current (physical) line.
+        // If there are newlines at the end of the file, they won't be represented in
+        // `noqa_line_for`, so fallback to the current line.
+        let noqa_lineno = noqa_line_for
+            .get(lineno)
+            .map(|lineno| lineno - 1)
+            .unwrap_or(lineno);
+
+        if !codes.is_empty() {
+            let matches = matches_by_line
+                .entry(noqa_lineno)
+                .or_insert_with(BTreeSet::new);
+            matches.append(&mut codes);
+        }
+    }
+
+    let mut count: usize = 0;
+    let mut output = "".to_string();
+    for (lineno, line) in lines.iter().enumerate() {
+        match matches_by_line.get(&lineno) {
+            None => {
+                output.push_str(line);
+                output.push('\n');
+            }
+            Some(codes) => {
+                match extract_noqa_directive(line) {
+                    Directive::None => {
+                        output.push_str(line);
+                    }
+                    Directive::All(start) => output.push_str(&line[..start]),
+                    Directive::Codes(start, _) => output.push_str(&line[..start]),
+                };
+                let codes: Vec<&str> = codes.iter().map(|code| code.as_str()).collect();
+                output.push_str("  # noqa: ");
+                output.push_str(&codes.join(", "));
+                output.push('\n');
+                count += 1;
+            }
+        }
+    }
+
+    Ok((count, output))
+}
+
+pub fn add_noqa(
+    checks: &Vec<Check>,
+    contents: &str,
+    noqa_line_for: &[usize],
+    path: &Path,
+) -> Result<usize> {
+    let (count, output) = add_noqa_inner(checks, contents, noqa_line_for)?;
+    fs::write(path, output)?;
+    Ok(count)
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::checks::{Check, CheckKind};
+    use anyhow::Result;
+    use rustpython_parser::ast::Location;
+    use rustpython_parser::lexer;
+    use rustpython_parser::lexer::LexResult;
+
+    use crate::noqa::{add_noqa_inner, extract_noqa_line_for};
+
+    #[test]
+    fn extraction() -> Result<()> {
+        let lxr: Vec<LexResult> = lexer::make_tokenizer(
+            "x = 1
+y = 2
+z = x + 1",
+        )
+        .collect();
+        println!("{:?}", extract_noqa_line_for(&lxr));
+        assert_eq!(extract_noqa_line_for(&lxr), vec![1, 2, 3]);
+
+        let lxr: Vec<LexResult> = lexer::make_tokenizer(
+            "
+x = 1
+y = 2
+z = x + 1",
+        )
+        .collect();
+        println!("{:?}", extract_noqa_line_for(&lxr));
+        assert_eq!(extract_noqa_line_for(&lxr), vec![1, 2, 3, 4]);
+
+        let lxr: Vec<LexResult> = lexer::make_tokenizer(
+            "x = 1
+y = 2
+z = x + 1
+        ",
+        )
+        .collect();
+        println!("{:?}", extract_noqa_line_for(&lxr));
+        assert_eq!(extract_noqa_line_for(&lxr), vec![1, 2, 3]);
+
+        let lxr: Vec<LexResult> = lexer::make_tokenizer(
+            "x = 1
+
+y = 2
+z = x + 1
+        ",
+        )
+        .collect();
+        println!("{:?}", extract_noqa_line_for(&lxr));
+        assert_eq!(extract_noqa_line_for(&lxr), vec![1, 2, 3, 4]);
+
+        let lxr: Vec<LexResult> = lexer::make_tokenizer(
+            "x = '''abc
+def
+ghi
+'''
+y = 2
+z = x + 1",
+        )
+        .collect();
+        assert_eq!(extract_noqa_line_for(&lxr), vec![4, 4, 4, 4, 5, 6]);
+
+        Ok(())
+    }
+
+    #[test]
+    fn modification() -> Result<()> {
+        let checks = vec![];
+        let contents = "x = 1";
+        let noqa_line_for = vec![1];
+        let (count, output) = add_noqa_inner(&checks, contents, &noqa_line_for)?;
+        assert_eq!(count, 0);
+        assert_eq!(output.trim(), contents.trim());
+
+        let checks = vec![Check::new(
+            CheckKind::UnusedVariable("x".to_string()),
+            Location::new(1, 1),
+        )];
+        let contents = "x = 1";
+        let noqa_line_for = vec![1];
+        let (count, output) = add_noqa_inner(&checks, contents, &noqa_line_for)?;
+        assert_eq!(count, 1);
+        assert_eq!(output.trim(), "x = 1  # noqa: F841".trim());
+
+        let checks = vec![
+            Check::new(
+                CheckKind::AmbiguousVariableName("x".to_string()),
+                Location::new(1, 1),
+            ),
+            Check::new(
+                CheckKind::UnusedVariable("x".to_string()),
+                Location::new(1, 1),
+            ),
+        ];
+        let contents = "x = 1  # noqa: E741";
+        let noqa_line_for = vec![1];
+        let (count, output) = add_noqa_inner(&checks, contents, &noqa_line_for)?;
+        assert_eq!(count, 1);
+        assert_eq!(output.trim(), "x = 1  # noqa: E741, F841".trim());
+
+        let checks = vec![
+            Check::new(
+                CheckKind::AmbiguousVariableName("x".to_string()),
+                Location::new(1, 1),
+            ),
+            Check::new(
+                CheckKind::UnusedVariable("x".to_string()),
+                Location::new(1, 1),
+            ),
+        ];
+        let contents = "x = 1  # noqa";
+        let noqa_line_for = vec![1];
+        let (count, output) = add_noqa_inner(&checks, contents, &noqa_line_for)?;
+        assert_eq!(count, 1);
+        assert_eq!(output.trim(), "x = 1  # noqa: E741, F841".trim());
+
+        Ok(())
+    }
+}
--- a/src/printer.rs
+++ b/src/printer.rs
@@ -1,7 +1,6 @@
-use colored::Colorize;
-
 use anyhow::Result;
 use clap::ValueEnum;
+use colored::Colorize;

 use crate::message::Message;
 use crate::tell_user;
@@ -14,11 +13,12 @@ pub enum SerializationFormat {

 pub struct Printer {
    format: SerializationFormat,
+    verbose: bool,
 }

 impl Printer {
-    pub fn new(format: SerializationFormat) -> Self {
-        Self { format }
+    pub fn new(format: SerializationFormat, verbose: bool) -> Self {
+        Self { format, verbose }
    }

    pub fn write_once(&mut self, messages: &[Message]) -> Result<()> {
@@ -40,7 +40,7 @@ impl Printer {
                        outstanding.len(),
                        fixed.len()
                    )
-                } else {
+                } else if !outstanding.is_empty() || self.verbose {
                    println!("Found {} error(s).", outstanding.len())
                }

--- a/src/pyproject.rs
+++ b/src/pyproject.rs
@@ -1,9 +1,8 @@
-use std::ops::Deref;
 use std::path::{Path, PathBuf};

 use anyhow::Result;
 use common_path::common_path_all;
-use path_absolutize::path_dedot;
+use path_absolutize::Absolutize;
 use serde::Deserialize;

 use crate::checks::CheckCode;
@@ -78,8 +77,10 @@ fn find_user_pyproject_toml() -> Option<PathBuf> {
 }

 pub fn find_project_root(sources: &[PathBuf]) -> Option<PathBuf> {
-    let cwd = path_dedot::CWD.deref();
-    let absolute_sources: Vec<PathBuf> = sources.iter().map(|source| cwd.join(source)).collect();
+    let absolute_sources: Vec<PathBuf> = sources
+        .iter()
+        .flat_map(|source| source.absolutize().map(|path| path.to_path_buf()))
+        .collect();
    if let Some(prefix) = common_path_all(absolute_sources.iter().map(PathBuf::as_path)) {
        for directory in prefix.ancestors() {
            if directory.join(".git").is_dir() {
--- a/src/python/typing.rs
+++ b/src/python/typing.rs
@@ -1,6 +1,7 @@
-use once_cell::sync::Lazy;
 use std::collections::BTreeSet;

+use once_cell::sync::Lazy;
+
 static ANNOTATED_SUBSCRIPTS: Lazy<BTreeSet<&'static str>> = Lazy::new(|| {
    BTreeSet::from([
        "AbstractAsyncContextManager",
--- a/src/settings.rs
+++ b/src/settings.rs
@@ -5,7 +5,7 @@ use std::path::{Path, PathBuf};
 use glob::Pattern;
 use once_cell::sync::Lazy;

-use crate::checks::{CheckCode, ALL_CHECK_CODES};
+use crate::checks::{CheckCode, DEFAULT_CHECK_CODES};
 use crate::fs;
 use crate::pyproject::load_config;

@@ -36,12 +36,38 @@ impl FilePattern {

 #[derive(Debug)]
 pub struct Settings {
+    pub pyproject: Option<PathBuf>,
+    pub project_root: Option<PathBuf>,
    pub line_length: usize,
    pub exclude: Vec<FilePattern>,
    pub extend_exclude: Vec<FilePattern>,
    pub select: BTreeSet<CheckCode>,
 }

+impl Settings {
+    pub fn for_rule(check_code: CheckCode) -> Self {
+        Self {
+            pyproject: None,
+            project_root: None,
+            line_length: 88,
+            exclude: vec![],
+            extend_exclude: vec![],
+            select: BTreeSet::from([check_code]),
+        }
+    }
+
+    pub fn for_rules(check_codes: Vec<CheckCode>) -> Self {
+        Self {
+            pyproject: None,
+            project_root: None,
+            line_length: 88,
+            exclude: vec![],
+            extend_exclude: vec![],
+            select: BTreeSet::from_iter(check_codes),
+        }
+    }
+}
+
 impl Hash for Settings {
    fn hash<H: Hasher>(&self, state: &mut H) {
        self.line_length.hash(state);
@@ -76,8 +102,8 @@ static DEFAULT_EXCLUDE: Lazy<Vec<FilePattern>> = Lazy::new(|| {
 });

 impl Settings {
-    pub fn from_pyproject(path: &Option<PathBuf>, project_root: &Option<PathBuf>) -> Self {
-        let config = load_config(path);
+    pub fn from_pyproject(pyproject: Option<PathBuf>, project_root: Option<PathBuf>) -> Self {
+        let config = load_config(&pyproject);
        let mut settings = Settings {
            line_length: config.line_length.unwrap_or(88),
            exclude: config
@@ -85,7 +111,7 @@ impl Settings {
                .map(|paths| {
                    paths
                        .iter()
-                        .map(|path| FilePattern::from_user(path, project_root))
+                        .map(|path| FilePattern::from_user(path, &project_root))
                        .collect()
                })
                .unwrap_or_else(|| DEFAULT_EXCLUDE.clone()),
@@ -94,15 +120,17 @@ impl Settings {
                .map(|paths| {
                    paths
                        .iter()
-                        .map(|path| FilePattern::from_user(path, project_root))
+                        .map(|path| FilePattern::from_user(path, &project_root))
                        .collect()
                })
                .unwrap_or_default(),
            select: if let Some(select) = config.select {
                BTreeSet::from_iter(select)
            } else {
-                BTreeSet::from_iter(ALL_CHECK_CODES)
+                BTreeSet::from_iter(DEFAULT_CHECK_CODES)
            },
+            pyproject,
+            project_root,
        };
        if let Some(ignore) = &config.ignore {
            settings.ignore(ignore);
@@ -110,8 +138,11 @@ impl Settings {
        settings
    }

-    pub fn select(&mut self, codes: Vec<CheckCode>) {
+    pub fn clear(&mut self) {
        self.select.clear();
+    }
+
+    pub fn select(&mut self, codes: Vec<CheckCode>) {
        for code in codes {
            self.select.insert(code);
        }
--- a/src/snapshots/rufflintertests__f402.snap
+++ b/src/snapshots/rufflintertests__f402.snap
@@ -0,0 +1,21 @@
+---
+source: src/linter.rs
+expression: checks
+---
+- kind:
+    ImportShadowedByLoopVar:
+      - os
+      - 1
+  location:
+    row: 5
+    column: 5
+  fix: ~
+- kind:
+    ImportShadowedByLoopVar:
+      - path
+      - 2
+  location:
+    row: 8
+    column: 5
+  fix: ~
+
--- a/src/snapshots/rufflintertests__f403.snap
+++ b/src/snapshots/rufflintertests__f403.snap
@@ -3,13 +3,13 @@ source: src/linter.rs
 expression: checks
 ---
 - kind:
-    ImportStarUsage: F634
+    ImportStarUsed: F634
  location:
    row: 1
    column: 1
  fix: ~
 - kind:
-    ImportStarUsage: F634
+    ImportStarUsed: F634
  location:
    row: 2
    column: 1
--- a/src/snapshots/rufflintertests__f405.snap
+++ b/src/snapshots/rufflintertests__f405.snap
@@ -0,0 +1,21 @@
+---
+source: src/linter.rs
+expression: checks
+---
+- kind:
+    ImportStarUsage:
+      - name
+      - mymodule
+  location:
+    row: 5
+    column: 11
+  fix: ~
+- kind:
+    ImportStarUsage:
+      - a
+      - mymodule
+  location:
+    row: 11
+    column: 1
+  fix: ~
+
--- a/src/snapshots/rufflintertests__f821.snap
+++ b/src/snapshots/rufflintertests__f821.snap
@@ -38,4 +38,16 @@ expression: checks
    row: 83
    column: 11
  fix: ~
+- kind:
+    UndefinedName: B
+  location:
+    row: 87
+    column: 7
+  fix: ~
+- kind:
+    UndefinedName: B
+  location:
+    row: 89
+    column: 7
+  fix: ~

--- a/src/snapshots/rufflintertests__m001.snap
+++ b/src/snapshots/rufflintertests__m001.snap
@@ -0,0 +1,89 @@
+---
+source: src/linter.rs
+expression: checks
+---
+- kind:
+    UnusedNOQA: ~
+  location:
+    row: 9
+    column: 10
+  fix:
+    content: ""
+    start:
+      row: 9
+      column: 10
+    end:
+      row: 9
+      column: 18
+    applied: false
+- kind:
+    UnusedNOQA: E501
+  location:
+    row: 13
+    column: 10
+  fix:
+    content: ""
+    start:
+      row: 13
+      column: 10
+    end:
+      row: 13
+      column: 24
+    applied: false
+- kind:
+    UnusedNOQA: E501
+  location:
+    row: 16
+    column: 10
+  fix:
+    content: "  # noqa: F841"
+    start:
+      row: 16
+      column: 10
+    end:
+      row: 16
+      column: 30
+    applied: false
+- kind:
+    UnusedNOQA: F841
+  location:
+    row: 41
+    column: 4
+  fix:
+    content: "  # noqa: E501"
+    start:
+      row: 41
+      column: 4
+    end:
+      row: 41
+      column: 24
+    applied: false
+- kind:
+    UnusedNOQA: E501
+  location:
+    row: 49
+    column: 4
+  fix:
+    content: ""
+    start:
+      row: 49
+      column: 4
+    end:
+      row: 49
+      column: 18
+    applied: false
+- kind:
+    UnusedNOQA: ~
+  location:
+    row: 57
+    column: 4
+  fix:
+    content: ""
+    start:
+      row: 57
+      column: 4
+    end:
+      row: 57
+      column: 12
+    applied: false
+
Author	SHA1	Message	Date
Charlie Marsh	b8f517c70e	Bump version to 0.0.45	2022-09-22 14:11:09 -04:00
Charlie Marsh	9f601c2abd	Document noqa workflows	2022-09-22 14:10:02 -04:00
Charlie Marsh	c0ce0b0c48	Enable automatic `noqa` insertion (#256 )	2022-09-22 13:59:06 -04:00
Charlie Marsh	e5b16973a9	Enable autofix for M001 (#255 )	2022-09-22 13:21:03 -04:00
Charlie Marsh	de9ceb2fe1	Only enforce multi-line noqa directives for strings (#258 )	2022-09-22 13:09:02 -04:00
Charlie Marsh	38b19b78b7	Enable noqa directives on logical lines (#257 )	2022-09-22 12:56:15 -04:00
Charlie Marsh	7043e15b57	Move noqa to a separate module	2022-09-22 09:04:54 -04:00
Charlie Marsh	9594079235	Add --extend-select and --extend-ignore (#254 )	2022-09-21 19:56:43 -04:00
Charlie Marsh	732f208e47	Add a lint rule to enforce noqa validity (#253 )	2022-09-21 19:56:38 -04:00
Charlie Marsh	32e62d9209	Use specific version tags	2022-09-21 15:11:53 -04:00
Charlie Marsh	d9e4b0cdc1	Implement --show-settings and --show-files (#246 )	2022-09-21 15:08:50 -04:00
Charlie Marsh	36fcfad56a	Remove empty comment	2022-09-21 13:44:49 -04:00
Charlie Marsh	65d29d9734	Adjust line numbers when reporting rules in f-strings (#244 )	2022-09-21 13:42:58 -04:00
Charlie Marsh	1e171ce0e8	Bump version to 0.0.44	2022-09-21 12:25:14 -04:00
Charlie Marsh	2bdc500c61	Re-run cargo insta	2022-09-21 12:24:46 -04:00
Charlie Marsh	f453e429b6	Add a note on parity	2022-09-21 12:24:04 -04:00
Charlie Marsh	73874f4788	Remove proof-of-concept caveat	2022-09-21 12:18:01 -04:00
Charlie Marsh	8846dcdf6a	Update README	2022-09-21 12:17:41 -04:00
Charlie Marsh	d827e6e36a	Implement F405 (#243 )	2022-09-21 12:13:40 -04:00
Harutaka Kawamura	71d9b2ac5f	Implement F402 (#221 )	2022-09-21 11:12:55 -04:00
Anders Kaseorg	401b53cc45	Handle filesystem errors more consistently (#240 )	2022-09-20 23:22:01 -04:00
Anders Kaseorg	aa9c1e255c	Simplify check_path type (#239 )	2022-09-20 21:11:42 -04:00
Anders Kaseorg	f7fc702b2c	Include specified files, even if they lack a .py[i] extension (#238 )	2022-09-20 20:53:52 -04:00
Anders Kaseorg	50ca0d7d0a	Correctly display the location of parse errors (#237 )	2022-09-20 20:53:22 -04:00
Anders Kaseorg	65e0284698	Suppress “Found 0 error(s)” message (#236 )	2022-09-20 19:32:39 -04:00
Charlie Marsh	e4f571ea61	Bump version to 0.0.43	2022-09-20 12:26:49 -04:00
Charlie Marsh	4ed88dd245	Follow-up fixes to path absolution (#235 )	2022-09-20 12:26:32 -04:00
Charlie Marsh	09b926fd59	Optimize imports	2022-09-20 09:10:39 -04:00
Charlie Marsh	a4869e4974	Update benchmark in README	2022-09-20 07:06:12 -06:00
Charlie Marsh	f53c4fc221	Bump version to 0.0.42	2022-09-19 21:14:17 -06:00
Charlie Marsh	3892a49a97	Bump version to 0.0.41	2022-09-19 21:09:33 -06:00