Bump version to 0.0.64

Cargo.lock

@@ -1907,7 +1907,7 @@ dependencies = [
 
 [[package]]
 name = "ruff"
-version = "0.0.62"
+version = "0.0.64"
 dependencies = [
  "anyhow",
  "bincode",
@@ -1926,6 +1926,7 @@ dependencies = [
  "libcst",
  "log",
  "notify",
+ "num-bigint",
  "once_cell",
  "path-absolutize",
  "rayon",
@@ -1957,7 +1958,7 @@ dependencies = [
 [[package]]
 name = "rustpython-ast"
 version = "0.1.0"
-source = "git+https://github.com/charliermarsh/RustPython.git?rev=4f457893efc381ad5c432576b24bcc7e4a08c641#4f457893efc381ad5c432576b24bcc7e4a08c641"
+source = "git+https://github.com/charliermarsh/RustPython.git?rev=778ae2aeb521d0438d2a91bd11238bb5c2bf9d4f#778ae2aeb521d0438d2a91bd11238bb5c2bf9d4f"
 dependencies = [
  "num-bigint",
  "rustpython-common",
@@ -1967,7 +1968,7 @@ dependencies = [
 [[package]]
 name = "rustpython-common"
 version = "0.0.0"
-source = "git+https://github.com/charliermarsh/RustPython.git?rev=4f457893efc381ad5c432576b24bcc7e4a08c641#4f457893efc381ad5c432576b24bcc7e4a08c641"
+source = "git+https://github.com/charliermarsh/RustPython.git?rev=778ae2aeb521d0438d2a91bd11238bb5c2bf9d4f#778ae2aeb521d0438d2a91bd11238bb5c2bf9d4f"
 dependencies = [
  "ascii",
  "cfg-if 1.0.0",
@@ -1990,7 +1991,7 @@ dependencies = [
 [[package]]
 name = "rustpython-compiler-core"
 version = "0.1.2"
-source = "git+https://github.com/charliermarsh/RustPython.git?rev=4f457893efc381ad5c432576b24bcc7e4a08c641#4f457893efc381ad5c432576b24bcc7e4a08c641"
+source = "git+https://github.com/charliermarsh/RustPython.git?rev=778ae2aeb521d0438d2a91bd11238bb5c2bf9d4f#778ae2aeb521d0438d2a91bd11238bb5c2bf9d4f"
 dependencies = [
  "bincode",
  "bitflags",
@@ -2007,7 +2008,7 @@ dependencies = [
 [[package]]
 name = "rustpython-parser"
 version = "0.1.2"
-source = "git+https://github.com/charliermarsh/RustPython.git?rev=4f457893efc381ad5c432576b24bcc7e4a08c641#4f457893efc381ad5c432576b24bcc7e4a08c641"
+source = "git+https://github.com/charliermarsh/RustPython.git?rev=778ae2aeb521d0438d2a91bd11238bb5c2bf9d4f#778ae2aeb521d0438d2a91bd11238bb5c2bf9d4f"
 dependencies = [
  "ahash",
  "anyhow",

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "ruff"
-version = "0.0.62"
+version = "0.0.64"
 edition = "2021"
 
 [lib]
@@ -27,9 +27,9 @@ 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-ast = { features = ["unparse"], git = "https://github.com/charliermarsh/RustPython.git", rev = "4f457893efc381ad5c432576b24bcc7e4a08c641" }
-rustpython-parser = { features = ["lalrpop"], git = "https://github.com/charliermarsh/RustPython.git", rev = "4f457893efc381ad5c432576b24bcc7e4a08c641" }
-rustpython-common = { git = "https://github.com/charliermarsh/RustPython.git", rev = "4f457893efc381ad5c432576b24bcc7e4a08c641" }
+rustpython-ast = { features = ["unparse"], git = "https://github.com/charliermarsh/RustPython.git", rev = "778ae2aeb521d0438d2a91bd11238bb5c2bf9d4f" }
+rustpython-parser = { features = ["lalrpop"], git = "https://github.com/charliermarsh/RustPython.git", rev = "778ae2aeb521d0438d2a91bd11238bb5c2bf9d4f" }
+rustpython-common = { git = "https://github.com/charliermarsh/RustPython.git", rev = "778ae2aeb521d0438d2a91bd11238bb5c2bf9d4f" }
 serde = { version = "1.0.143", features = ["derive"] }
 serde_json = { version = "1.0.83" }
 toml = { version = "0.5.9" }
@@ -37,6 +37,7 @@ update-informer = { version = "0.5.0", default_features = false, features = ["py
 walkdir = { version = "2.3.2" }
 strum = { version = "0.24.1", features = ["strum_macros"] }
 strum_macros = "0.24.3"
+num-bigint = "0.4.3"
 
 [dev-dependencies]
 insta = { version = "1.19.1", features = ["yaml"] }

README.md

@@ -286,6 +286,7 @@ The 🛠 emoji indicates that a rule is automatically fixable by the `--fix` com
 | C405 | UnnecessaryLiteralSet | Unnecessary <list/tuple> literal - rewrite as a set literal |  |  |
 | C406 | UnnecessaryLiteralDict | Unnecessary <list/tuple> literal - rewrite as a dict literal |  |  |
 | C408 | UnnecessaryCollectionCall | Unnecessary <dict/list/tuple> call - rewrite as a literal |  |  |
+| C415 | UnnecessarySubscriptReversal | Unnecessary subscript reversal of iterable within <reversed/set/sorted>() |  |  |
 | SPR001 | SuperCallWithParameters | Use `super()` instead of `super(__class__, self)` |  | 🛠 |
 | T201 | PrintFound | `print` found |  | 🛠 |
 | T203 | PPrintFound | `pprint` found |  | 🛠 |
@@ -295,7 +296,7 @@ The 🛠 emoji indicates that a rule is automatically fixable by the `--fix` com
 | U004 | UselessObjectInheritance | Class `...` inherits from object |  | 🛠 |
 | U005 | NoAssertEquals | `assertEquals` is deprecated, use `assertEqual` instead |  | 🛠 |
 | U006 | UsePEP585Annotation | Use `list` instead of `List` for type annotations |  | 🛠 |
-| U007 | UsePEP604Annotation | Use `X | Y` for type annotations |  | 🛠 |
+| U007 | UsePEP604Annotation | Use `X \| Y` for type annotations |  | 🛠 |
 | M001 | UnusedNOQA | Unused `noqa` directive |  | 🛠 |
 
 ## Integrations

examples/generate_rules_table.rs

@@ -18,7 +18,7 @@ fn main() {
             "| {} | {} | {} | {} | {} |",
             check_kind.code().as_ref(),
             check_kind.as_ref(),
-            check_kind.body(),
+            check_kind.body().replace("|", r"\|"),
             default_token,
             fix_token
         );

resources/test/fixtures/C415.py

@@ -0,0 +1,9 @@
+lst = [2, 1, 3]
+a = set(lst[::-1])
+b = reversed(lst[::-1])
+c = sorted(lst[::-1])
+d = sorted(lst[::-1], reverse=True)
+e = set(lst[2:-1])
+f = set(lst[:1:-1])
+g = set(lst[::1])
+h = set(lst[::-2])

resources/test/fixtures/F401.py

@@ -65,3 +65,24 @@ b = Union["Nut", None]
 c = cast("Vegetable", b)
 
 Field = lambda default=MISSING: field(default=default)
+
+
+# Test: access a sub-importation via an alias.
+import pyarrow as pa
+import pyarrow.csv
+
+print(pa.csv.read_csv("test.csv"))
+
+
+# Test: referencing an import via TypeAlias.
+import sys
+
+import numpy as np
+
+if sys.version_info >= (3, 10):
+    from typing import TypeAlias
+else:
+    from typing_extensions import TypeAlias
+
+
+CustomInt: TypeAlias = "np.int8 | np.int16"

src/ast/checks.rs

@@ -1,6 +1,7 @@
 use std::collections::BTreeSet;
 
 use itertools::izip;
+use num_bigint::BigInt;
 use regex::Regex;
 use rustpython_parser::ast::{
     Arg, ArgData, Arguments, Cmpop, Constant, Excepthandler, ExcepthandlerKind, Expr, ExprKind,
@@ -985,6 +986,44 @@ pub fn unnecessary_collection_call(
     None
 }
 
+pub fn unnecessary_subscript_reversal(expr: &Expr, func: &Expr, args: &[Expr]) -> Option<Check> {
+    if let Some(first_arg) = args.first() {
+        if let ExprKind::Name { id, .. } = &func.node {
+            if id == "set" || id == "sorted" || id == "reversed" {
+                if let ExprKind::Subscript { slice, .. } = &first_arg.node {
+                    if let ExprKind::Slice { lower, upper, step } = &slice.node {
+                        if lower.is_none() && upper.is_none() {
+                            if let Some(step) = step {
+                                if let ExprKind::UnaryOp {
+                                    op: Unaryop::USub,
+                                    operand,
+                                } = &step.node
+                                {
+                                    if let ExprKind::Constant {
+                                        value: Constant::Int(val),
+                                        ..
+                                    } = &operand.node
+                                    {
+                                        if *val == BigInt::from(1) {
+                                            return Some(Check::new(
+                                                CheckKind::UnnecessarySubscriptReversal(
+                                                    id.to_string(),
+                                                ),
+                                                Range::from_located(expr),
+                                            ));
+                                        }
+                                    }
+                                }
+                            }
+                        }
+                    }
+                }
+            }
+        }
+    }
+    None
+}
+
 // flake8-super
 /// Check that `super()` has no args
 pub fn check_super_args(

src/ast/helpers.rs

@@ -1,4 +1,69 @@
-use rustpython_ast::{Expr, ExprKind};
+use once_cell::sync::Lazy;
+use regex::Regex;
+use rustpython_ast::{Expr, ExprKind, StmtKind};
+
+use crate::python::typing;
+
+static DUNDER_REGEX: Lazy<Regex> = Lazy::new(|| Regex::new(r"__[^\s]+__").unwrap());
+
+pub enum SubscriptKind {
+    AnnotatedSubscript,
+    PEP593AnnotatedSubscript,
+}
+
+pub fn match_annotated_subscript(expr: &Expr) -> Option<SubscriptKind> {
+    match &expr.node {
+        ExprKind::Attribute { attr, .. } => {
+            if typing::is_annotated_subscript(attr) {
+                Some(SubscriptKind::AnnotatedSubscript)
+            } else if typing::is_pep593_annotated_subscript(attr) {
+                Some(SubscriptKind::PEP593AnnotatedSubscript)
+            } else {
+                None
+            }
+        }
+        ExprKind::Name { id, .. } => {
+            if typing::is_annotated_subscript(id) {
+                Some(SubscriptKind::AnnotatedSubscript)
+            } else if typing::is_pep593_annotated_subscript(id) {
+                Some(SubscriptKind::PEP593AnnotatedSubscript)
+            } else {
+                None
+            }
+        }
+        _ => None,
+    }
+}
+
+pub fn is_assignment_to_a_dunder(node: &StmtKind) -> bool {
+    // Check whether it's an assignment to a dunder, with or without a type annotation.
+    // This is what pycodestyle (as of 2.9.1) does.
+    match node {
+        StmtKind::Assign {
+            targets,
+            value: _,
+            type_comment: _,
+        } => {
+            if targets.len() != 1 {
+                return false;
+            }
+            match &targets[0].node {
+                ExprKind::Name { id, ctx: _ } => DUNDER_REGEX.is_match(id),
+                _ => false,
+            }
+        }
+        StmtKind::AnnAssign {
+            target,
+            annotation: _,
+            value: _,
+            simple: _,
+        } => match &target.node {
+            ExprKind::Name { id, ctx: _ } => DUNDER_REGEX.is_match(id),
+            _ => false,
+        },
+        _ => false,
+    }
+}
 
 pub fn match_name_or_attr(expr: &Expr, target: &str) -> bool {
     match &expr.node {

src/ast/types.rs

@@ -74,9 +74,9 @@ pub enum BindingKind {
     Export(Vec<String>),
     FutureImportation,
     StarImportation,
-    Importation(String, BindingContext),
-    FromImportation(String, BindingContext),
-    SubmoduleImportation(String, BindingContext),
+    Importation(String, String, BindingContext),
+    FromImportation(String, String, BindingContext),
+    SubmoduleImportation(String, String, BindingContext),
 }
 
 #[derive(Clone, Debug)]

src/ast/visitor.rs

@@ -1,3 +1,4 @@
+use crate::ast::helpers::match_name_or_attr;
 use rustpython_parser::ast::{
     Alias, Arg, Arguments, Boolop, Cmpop, Comprehension, Constant, Excepthandler,
     ExcepthandlerKind, Expr, ExprContext, ExprKind, Keyword, MatchCase, Operator, Pattern,
@@ -148,7 +149,11 @@ pub fn walk_stmt<'a, V: Visitor<'a> + ?Sized>(visitor: &mut V, stmt: &'a Stmt) {
         } => {
             visitor.visit_annotation(annotation);
             if let Some(expr) = value {
-                visitor.visit_expr(expr);
+                if match_name_or_attr(annotation, "TypeAlias") {
+                    visitor.visit_annotation(expr);
+                } else {
+                    visitor.visit_expr(expr);
+                }
             }
             visitor.visit_expr(target);
         }

src/check_ast.rs

@@ -3,8 +3,6 @@ use std::ops::Deref;
 use std::path::Path;
 
 use log::error;
-use once_cell::sync::Lazy;
-use regex::Regex;
 use rustpython_ast::Location;
 use rustpython_parser::ast::{
     Arg, Arguments, Constant, Excepthandler, ExcepthandlerKind, Expr, ExprContext, ExprKind,
@@ -12,7 +10,7 @@ use rustpython_parser::ast::{
 };
 use rustpython_parser::parser;
 
-use crate::ast::helpers::match_name_or_attr;
+use crate::ast::helpers::{match_name_or_attr, SubscriptKind};
 use crate::ast::operations::{extract_all_names, SourceCodeLocator};
 use crate::ast::relocate::relocate_expr;
 use crate::ast::types::{
@@ -20,19 +18,16 @@ use crate::ast::types::{
     ScopeKind,
 };
 use crate::ast::visitor::{walk_excepthandler, Visitor};
-use crate::ast::{checks, operations, visitor};
+use crate::ast::{checks, helpers, operations, visitor};
 use crate::autofix::{fixer, fixes};
 use crate::checks::{Check, CheckCode, CheckKind};
 use crate::plugins;
 use crate::python::builtins::{BUILTINS, MAGIC_GLOBALS};
 use crate::python::future::ALL_FEATURE_NAMES;
-use crate::python::typing;
 use crate::settings::{PythonVersion, Settings};
 
 pub const GLOBAL_SCOPE_INDEX: usize = 0;
 
-static DUNDER_REGEX: Lazy<Regex> = Lazy::new(|| Regex::new(r"__[^\s]+__").unwrap());
-
 pub struct Checker<'a> {
     // Input data.
     path: &'a Path,
@@ -102,65 +97,6 @@ impl<'a> Checker<'a> {
     }
 }
 
-enum SubscriptKind {
-    AnnotatedSubscript,
-    PEP593AnnotatedSubscript,
-}
-
-fn match_annotated_subscript(expr: &Expr) -> Option<SubscriptKind> {
-    match &expr.node {
-        ExprKind::Attribute { attr, .. } => {
-            if typing::is_annotated_subscript(attr) {
-                Some(SubscriptKind::AnnotatedSubscript)
-            } else if typing::is_pep593_annotated_subscript(attr) {
-                Some(SubscriptKind::PEP593AnnotatedSubscript)
-            } else {
-                None
-            }
-        }
-        ExprKind::Name { id, .. } => {
-            if typing::is_annotated_subscript(id) {
-                Some(SubscriptKind::AnnotatedSubscript)
-            } else if typing::is_pep593_annotated_subscript(id) {
-                Some(SubscriptKind::PEP593AnnotatedSubscript)
-            } else {
-                None
-            }
-        }
-        _ => None,
-    }
-}
-
-fn is_assignment_to_a_dunder(node: &StmtKind) -> bool {
-    // Check whether it's an assignment to a dunder, with or without a type annotation.
-    // This is what pycodestyle (as of 2.9.1) does.
-    match node {
-        StmtKind::Assign {
-            targets,
-            value: _,
-            type_comment: _,
-        } => {
-            if targets.len() != 1 {
-                return false;
-            }
-            match &targets[0].node {
-                ExprKind::Name { id, ctx: _ } => DUNDER_REGEX.is_match(id),
-                _ => false,
-            }
-        }
-        StmtKind::AnnAssign {
-            target,
-            annotation: _,
-            value: _,
-            simple: _,
-        } => match &target.node {
-            ExprKind::Name { id, ctx: _ } => DUNDER_REGEX.is_match(id),
-            _ => false,
-        },
-        _ => false,
-    }
-}
-
 impl<'a, 'b> Visitor<'b> for Checker<'a>
 where
     'b: 'a,
@@ -221,7 +157,7 @@ where
                 self.futures_allowed = false;
 
                 if !self.seen_non_import
-                    && !is_assignment_to_a_dunder(node)
+                    && !helpers::is_assignment_to_a_dunder(node)
                     && !operations::in_nested_block(&self.parent_stack, &self.parents)
                 {
                     self.seen_non_import = true;
@@ -428,13 +364,16 @@ where
 
                 for alias in names {
                     if alias.node.name.contains('.') && alias.node.asname.is_none() {
-                        // TODO(charlie): Multiple submodule imports with the same parent module
-                        // will be merged into a single binding.
+                        // Given `import foo.bar`, `name` would be "foo", and `full_name` would be
+                        // "foo.bar".
+                        let name = alias.node.name.split('.').next().unwrap();
+                        let full_name = &alias.node.name;
                         self.add_binding(
-                            alias.node.name.split('.').next().unwrap().to_string(),
+                            name.to_string(),
                             Binding {
                                 kind: BindingKind::SubmoduleImportation(
-                                    alias.node.name.to_string(),
+                                    name.to_string(),
+                                    full_name.to_string(),
                                     self.binding_context(),
                                 ),
                                 used: None,
@@ -446,19 +385,17 @@ where
                             self.check_builtin_shadowing(asname, Range::from_located(stmt), false);
                         }
 
+                        // Given `import foo`, `name` and `full_name` would both be `foo`.
+                        // Given `import foo as bar`, `name` would be `bar` and `full_name` would
+                        // be `foo`.
+                        let name = alias.node.asname.as_ref().unwrap_or(&alias.node.name);
+                        let full_name = &alias.node.name;
                         self.add_binding(
-                            alias
-                                .node
-                                .asname
-                                .clone()
-                                .unwrap_or_else(|| alias.node.name.clone()),
+                            name.to_string(),
                             Binding {
                                 kind: BindingKind::Importation(
-                                    alias
-                                        .node
-                                        .asname
-                                        .clone()
-                                        .unwrap_or_else(|| alias.node.name.clone()),
+                                    name.to_string(),
+                                    full_name.to_string(),
                                     self.binding_context(),
                                 ),
                                 used: None,
@@ -487,14 +424,10 @@ where
                 }
 
                 for alias in names {
-                    let name = alias
-                        .node
-                        .asname
-                        .clone()
-                        .unwrap_or_else(|| alias.node.name.clone());
                     if let Some("__future__") = module.as_deref() {
+                        let name = alias.node.asname.as_ref().unwrap_or(&alias.node.name);
                         self.add_binding(
-                            name,
+                            name.to_string(),
                             Binding {
                                 kind: BindingKind::FutureImportation,
                                 used: Some((
@@ -573,18 +506,26 @@ where
                             self.check_builtin_shadowing(asname, Range::from_located(stmt), false);
                         }
 
-                        let binding = Binding {
-                            kind: BindingKind::FromImportation(
-                                match module {
-                                    None => name.clone(),
-                                    Some(parent) => format!("{}.{}", parent, name),
-                                },
-                                self.binding_context(),
-                            ),
-                            used: None,
-                            range: Range::from_located(stmt),
+                        // Given `from foo import bar`, `name` would be "bar" and `full_name` would
+                        // be "foo.bar". Given `from foo import bar as baz`, `name` would be "baz"
+                        // and `full_name` would be "foo.bar".
+                        let name = alias.node.asname.as_ref().unwrap_or(&alias.node.name);
+                        let full_name = match module {
+                            None => alias.node.name.to_string(),
+                            Some(parent) => format!("{}.{}", parent, alias.node.name),
                         };
-                        self.add_binding(name, binding)
+                        self.add_binding(
+                            name.to_string(),
+                            Binding {
+                                kind: BindingKind::FromImportation(
+                                    name.to_string(),
+                                    full_name,
+                                    self.binding_context(),
+                                ),
+                                used: None,
+                                range: Range::from_located(stmt),
+                            },
+                        )
                     }
                 }
             }
@@ -847,6 +788,12 @@ where
                     };
                 }
 
+                if self.settings.enabled.contains(&CheckCode::C415) {
+                    if let Some(check) = checks::unnecessary_subscript_reversal(expr, func, args) {
+                        self.checks.push(check);
+                    };
+                }
+
                 // pyupgrade
                 if self.settings.enabled.contains(&CheckCode::U002)
                     && self.settings.target_version >= PythonVersion::Py310
@@ -1131,7 +1078,7 @@ where
                 }
             }
             ExprKind::Subscript { value, slice, ctx } => {
-                match match_annotated_subscript(value) {
+                match helpers::match_annotated_subscript(value) {
                     Some(subscript) => match subscript {
                         // Ex) Optional[int]
                         SubscriptKind::AnnotatedSubscript => {
@@ -1313,6 +1260,47 @@ impl CheckLocator for Checker<'_> {
     }
 }
 
+fn try_mark_used(scope: &mut Scope, scope_id: usize, id: &str, expr: &Expr) -> bool {
+    let alias = if let Some(binding) = scope.values.get_mut(id) {
+        // Mark the binding as used.
+        binding.used = Some((scope_id, Range::from_located(expr)));
+
+        // If the name of the sub-importation is the same as an alias of another importation and the
+        // alias is used, that sub-importation should be marked as used too.
+        //
+        // This handles code like:
+        //   import pyarrow as pa
+        //   import pyarrow.csv
+        //   print(pa.csv.read_csv("test.csv"))
+        if let BindingKind::Importation(name, full_name, _)
+        | BindingKind::FromImportation(name, full_name, _)
+        | BindingKind::SubmoduleImportation(name, full_name, _) = &binding.kind
+        {
+            let has_alias = full_name
+                .split('.')
+                .last()
+                .map(|segment| segment != name)
+                .unwrap_or_default();
+            if has_alias {
+                // Clone the alias. (We'll mutate it below.)
+                full_name.to_string()
+            } else {
+                return true;
+            }
+        } else {
+            return true;
+        }
+    } else {
+        return false;
+    };
+
+    // Mark the sub-importation as used.
+    if let Some(binding) = scope.values.get_mut(&alias) {
+        binding.used = Some((scope_id, Range::from_located(expr)));
+    }
+    true
+}
+
 impl<'a> Checker<'a> {
     pub fn add_check(&mut self, check: Check) {
         self.checks.push(check);
@@ -1396,7 +1384,11 @@ impl<'a> Checker<'a> {
                     && matches!(binding.kind, BindingKind::LoopVar)
                     && matches!(
                         existing.kind,
-                        BindingKind::Importation(_, _) | BindingKind::FromImportation(_, _)
+                        BindingKind::Importation(_, _, _)
+                            | BindingKind::FromImportation(_, _, _)
+                            | BindingKind::SubmoduleImportation(_, _, _)
+                            | BindingKind::StarImportation
+                            | BindingKind::FutureImportation
                     )
                 {
                     self.checks.push(Check::new(
@@ -1435,8 +1427,8 @@ impl<'a> Checker<'a> {
                         continue;
                     }
                 }
-                if let Some(binding) = scope.values.get_mut(id) {
-                    binding.used = Some((scope_id, Range::from_located(expr)));
+
+                if try_mark_used(scope, scope_id, id, expr) {
                     return;
                 }
 
@@ -1771,7 +1763,7 @@ impl<'a> Checker<'a> {
 
                     if !used {
                         match &binding.kind {
-                            BindingKind::FromImportation(full_name, context) => {
+                            BindingKind::FromImportation(_, full_name, context) => {
                                 let full_names = unused
                                     .entry((
                                         ImportKind::ImportFrom,
@@ -1781,8 +1773,8 @@ impl<'a> Checker<'a> {
                                     .or_default();
                                 full_names.push(full_name);
                             }
-                            BindingKind::Importation(full_name, context)
-                            | BindingKind::SubmoduleImportation(full_name, context) => {
+                            BindingKind::Importation(_, full_name, context)
+                            | BindingKind::SubmoduleImportation(_, full_name, context) => {
                                 let full_names = unused
                                     .entry((
                                         ImportKind::Import,

src/check_lines.rs

@@ -1,8 +1,8 @@
 use std::collections::BTreeMap;
 
-use crate::ast::types::Range;
 use rustpython_parser::ast::Location;
 
+use crate::ast::types::Range;
 use crate::autofix::fixer;
 use crate::checks::{Check, CheckCode, CheckKind, Fix};
 use crate::noqa;

src/checks.rs

@@ -129,6 +129,7 @@ pub enum CheckCode {
     C405,
     C406,
     C408,
+    C415,
     // flake8-super
     SPR001,
     // flake8-print
@@ -219,6 +220,7 @@ pub enum CheckKind {
     UnnecessaryLiteralSet(String),
     UnnecessaryLiteralDict(String),
     UnnecessaryCollectionCall(String),
+    UnnecessarySubscriptReversal(String),
     // flake8-super
     SuperCallWithParameters,
     // flake8-print
@@ -312,6 +314,9 @@ impl CheckCode {
             CheckCode::C408 => {
                 CheckKind::UnnecessaryCollectionCall("<dict/list/tuple>".to_string())
             }
+            CheckCode::C415 => {
+                CheckKind::UnnecessarySubscriptReversal("<reversed/set/sorted>".to_string())
+            }
             // flake8-super
             CheckCode::SPR001 => CheckKind::SuperCallWithParameters,
             // flake8-print
@@ -393,6 +398,7 @@ impl CheckKind {
             CheckKind::UnnecessaryLiteralSet(_) => &CheckCode::C405,
             CheckKind::UnnecessaryLiteralDict(_) => &CheckCode::C406,
             CheckKind::UnnecessaryCollectionCall(_) => &CheckCode::C408,
+            CheckKind::UnnecessarySubscriptReversal(_) => &CheckCode::C415,
             // flake8-super
             CheckKind::SuperCallWithParameters => &CheckCode::SPR001,
             // flake8-print
@@ -579,6 +585,9 @@ impl CheckKind {
             CheckKind::UnnecessaryCollectionCall(obj_type) => {
                 format!("Unnecessary {obj_type} call - rewrite as a literal")
             }
+            CheckKind::UnnecessarySubscriptReversal(func) => {
+                format!("Unnecessary subscript reversal of iterable within {func}()")
+            }
             // flake8-super
             CheckKind::SuperCallWithParameters => {
                 "Use `super()` instead of `super(__class__, self)`".to_string()

src/linter.rs

@@ -894,6 +894,18 @@ mod tests {
         Ok(())
     }
 
+    #[test]
+    fn c415() -> Result<()> {
+        let mut checks = check_path(
+            Path::new("./resources/test/fixtures/C415.py"),
+            &settings::Settings::for_rule(CheckCode::C415),
+            &fixer::Mode::Generate,
+        )?;
+        checks.sort_by_key(|check| check.location);
+        insta::assert_yaml_snapshot!(checks);
+        Ok(())
+    }
+
     #[test]
     fn spr001() -> Result<()> {
         let mut checks = check_path(

src/noqa.rs

@@ -150,12 +150,12 @@ pub fn add_noqa(
 
 #[cfg(test)]
 mod tests {
-    use crate::ast::types::Range;
     use anyhow::Result;
     use rustpython_parser::ast::Location;
     use rustpython_parser::lexer;
     use rustpython_parser::lexer::LexResult;
 
+    use crate::ast::types::Range;
     use crate::checks::{Check, CheckKind};
     use crate::noqa::{add_noqa_inner, extract_noqa_line_for};
 

src/plugins.rs

@@ -1,16 +1,3 @@
-mod assert_equals;
-mod assert_tuple;
-mod if_tuple;
-mod invalid_print_syntax;
-mod print_call;
-mod super_call_with_parameters;
-mod type_of_primitive;
-mod unnecessary_abspath;
-mod use_pep585_annotation;
-mod use_pep604_annotation;
-mod useless_metaclass_type;
-mod useless_object_inheritance;
-
 pub use assert_equals::assert_equals;
 pub use assert_tuple::assert_tuple;
 pub use if_tuple::if_tuple;
@@ -23,3 +10,16 @@ pub use use_pep585_annotation::use_pep585_annotation;
 pub use use_pep604_annotation::use_pep604_annotation;
 pub use useless_metaclass_type::useless_metaclass_type;
 pub use useless_object_inheritance::useless_object_inheritance;
+
+mod assert_equals;
+mod assert_tuple;
+mod if_tuple;
+mod invalid_print_syntax;
+mod print_call;
+mod super_call_with_parameters;
+mod type_of_primitive;
+mod unnecessary_abspath;
+mod use_pep585_annotation;
+mod use_pep604_annotation;
+mod useless_metaclass_type;
+mod useless_object_inheritance;

src/plugins/use_pep604_annotation.rs

@@ -1,5 +1,4 @@
-use anyhow::{anyhow, Result};
-use rustpython_ast::{Expr, ExprKind};
+use rustpython_ast::{Constant, Expr, ExprKind, Operator};
 
 use crate::ast::helpers::match_name_or_attr;
 use crate::ast::types::Range;
@@ -8,15 +7,50 @@ use crate::check_ast::Checker;
 use crate::checks::{Check, CheckKind, Fix};
 use crate::code_gen::SourceGenerator;
 
+fn optional(expr: &Expr) -> Expr {
+    Expr::new(
+        Default::default(),
+        Default::default(),
+        ExprKind::BinOp {
+            left: Box::new(expr.clone()),
+            op: Operator::BitOr,
+            right: Box::new(Expr::new(
+                Default::default(),
+                Default::default(),
+                ExprKind::Constant {
+                    value: Constant::None,
+                    kind: None,
+                },
+            )),
+        },
+    )
+}
+
+fn union(elts: &[Expr]) -> Expr {
+    if elts.len() == 1 {
+        elts[0].clone()
+    } else {
+        Expr::new(
+            Default::default(),
+            Default::default(),
+            ExprKind::BinOp {
+                left: Box::new(union(&elts[..elts.len() - 1])),
+                op: Operator::BitOr,
+                right: Box::new(elts[elts.len() - 1].clone()),
+            },
+        )
+    }
+}
+
 pub fn use_pep604_annotation(checker: &mut Checker, expr: &Expr, value: &Expr, slice: &Expr) {
     if match_name_or_attr(value, "Optional") {
         let mut check = Check::new(CheckKind::UsePEP604Annotation, Range::from_located(expr));
         if matches!(checker.autofix, fixer::Mode::Generate | fixer::Mode::Apply) {
             let mut generator = SourceGenerator::new();
-            if let Ok(()) = generator.unparse_expr(slice, 0) {
+            if let Ok(()) = generator.unparse_expr(&optional(slice), 0) {
                 if let Ok(content) = generator.generate() {
                     check.amend(Fix {
-                        content: format!("{} | None", content),
+                        content,
                         location: expr.location,
                         end_location: expr.end_location,
                         applied: false,
@@ -33,27 +67,16 @@ pub fn use_pep604_annotation(checker: &mut Checker, expr: &Expr, value: &Expr, s
                     // Invalid type annotation.
                 }
                 ExprKind::Tuple { elts, .. } => {
-                    // Multiple arguments.
-                    let parts: Result<Vec<String>> = elts
-                        .iter()
-                        .map(|expr| {
-                            let mut generator = SourceGenerator::new();
-                            generator
-                                .unparse_expr(expr, 0)
-                                .map_err(|_| anyhow!("Failed to parse."))?;
-                            generator
-                                .generate()
-                                .map_err(|_| anyhow!("Failed to generate."))
-                        })
-                        .collect();
-                    if let Ok(parts) = parts {
-                        let content = parts.join(" | ");
-                        check.amend(Fix {
-                            content,
-                            location: expr.location,
-                            end_location: expr.end_location,
-                            applied: false,
-                        })
+                    let mut generator = SourceGenerator::new();
+                    if let Ok(()) = generator.unparse_expr(&union(elts), 0) {
+                        if let Ok(content) = generator.generate() {
+                            check.amend(Fix {
+                                content,
+                                location: expr.location,
+                                end_location: expr.end_location,
+                                applied: false,
+                            })
+                        }
                     }
                 }
                 _ => {

src/pyproject.rs

@@ -154,12 +154,13 @@ mod tests {
 
     use anyhow::Result;
 
-    use super::StrCheckCodePair;
     use crate::checks::CheckCode;
     use crate::pyproject::{
         find_project_root, find_pyproject_toml, parse_pyproject_toml, Config, PyProject, Tools,
     };
 
+    use super::StrCheckCodePair;
+
     #[test]
     fn deserialize() -> Result<()> {
         let pyproject: PyProject = toml::from_str(r#""#)?;

src/snapshots/ruff__linter__tests__c415.snap

@@ -0,0 +1,41 @@
+---
+source: src/linter.rs
+expression: checks
+---
+- kind:
+    UnnecessarySubscriptReversal: set
+  location:
+    row: 2
+    column: 5
+  end_location:
+    row: 2
+    column: 19
+  fix: ~
+- kind:
+    UnnecessarySubscriptReversal: reversed
+  location:
+    row: 3
+    column: 5
+  end_location:
+    row: 3
+    column: 24
+  fix: ~
+- kind:
+    UnnecessarySubscriptReversal: sorted
+  location:
+    row: 4
+    column: 5
+  end_location:
+    row: 4
+    column: 22
+  fix: ~
+- kind:
+    UnnecessarySubscriptReversal: sorted
+  location:
+    row: 5
+    column: 5
+  end_location:
+    row: 5
+    column: 36
+  fix: ~
+