[red-knot] Method calls and descriptor protocol
This commit is contained in:
@@ -73,12 +73,12 @@ qux = (foo, bar)
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reveal_type(qux) # revealed: tuple[Literal["foo"], Literal["bar"]]
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# TODO: Infer "LiteralString"
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reveal_type(foo.join(qux)) # revealed: @Todo(Attribute access on `StringLiteral` types)
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reveal_type(foo.join(qux)) # revealed: @Todo(decorated method)
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template: LiteralString = "{}, {}"
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reveal_type(template) # revealed: Literal["{}, {}"]
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# TODO: Infer `LiteralString`
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reveal_type(template.format(foo, bar)) # revealed: @Todo(Attribute access on `StringLiteral` types)
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reveal_type(template.format(foo, bar)) # revealed: @Todo(decorated method)
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```
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### Assignability
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@@ -1005,8 +1005,8 @@ reveal_type(f.__kwdefaults__) # revealed: @Todo(generics) | None
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Some attributes are special-cased, however:
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```py
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reveal_type(f.__get__) # revealed: @Todo(`__get__` method on functions)
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reveal_type(f.__call__) # revealed: @Todo(`__call__` method on functions)
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reveal_type(f.__get__) # revealed: <method-wrapper `__get__` of `f`>
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reveal_type(f.__call__) # revealed: <bound method `__call__` of `Literal[f]`>
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```
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### Int-literal attributes
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@@ -1015,7 +1015,7 @@ Most attribute accesses on int-literal types are delegated to `builtins.int`, si
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integers are instances of that class:
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```py
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reveal_type((2).bit_length) # revealed: @Todo(bound method)
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reveal_type((2).bit_length) # revealed: <bound method `bit_length` of `Literal[2]`>
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reveal_type((2).denominator) # revealed: @Todo(@property)
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```
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@@ -1029,11 +1029,11 @@ reveal_type((2).real) # revealed: Literal[2]
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### Bool-literal attributes
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Most attribute accesses on bool-literal types are delegated to `builtins.bool`, since all literal
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bols are instances of that class:
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bools are instances of that class:
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```py
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reveal_type(True.__and__) # revealed: @Todo(bound method)
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reveal_type(False.__or__) # revealed: @Todo(bound method)
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reveal_type(True.__and__) # revealed: @Todo(decorated method)
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reveal_type(False.__or__) # revealed: @Todo(decorated method)
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```
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Some attributes are special-cased, however:
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@@ -1048,8 +1048,8 @@ reveal_type(False.real) # revealed: Literal[0]
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All attribute access on literal `bytes` types is currently delegated to `buitins.bytes`:
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```py
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reveal_type(b"foo".join) # revealed: @Todo(bound method)
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reveal_type(b"foo".endswith) # revealed: @Todo(bound method)
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reveal_type(b"foo".join) # revealed: <bound method `join` of `Literal[b"foo"]`>
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reveal_type(b"foo".endswith) # revealed: <bound method `endswith` of `Literal[b"foo"]`>
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```
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## Instance attribute edge cases
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@@ -1136,6 +1136,42 @@ class C:
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reveal_type(C().x) # revealed: Unknown
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```
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### Builtin types attributes
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This test can probably be removed eventually, but we currently include it because we do not yet
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understand generic bases and protocols, and we want to make sure that we can still use builtin types
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in our tests in the meantime. See the corresponding TODO in `Type::static_member` for more
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information.
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```py
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class C:
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a_int: int = 1
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a_str: str = "a"
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a_bytes: bytes = b"a"
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a_bool: bool = True
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a_float: float = 1.0
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a_complex: complex = 1 + 1j
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a_tuple: tuple[int] = (1,)
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a_range: range = range(1)
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a_slice: slice = slice(1)
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a_memoryview: memoryview = memoryview(b"a")
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a_type: type = int
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a_none: None = None
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reveal_type(C.a_int) # revealed: int
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reveal_type(C.a_str) # revealed: str
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reveal_type(C.a_bytes) # revealed: bytes
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reveal_type(C.a_bool) # revealed: bool
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reveal_type(C.a_float) # revealed: int | float
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reveal_type(C.a_complex) # revealed: int | float | complex
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reveal_type(C.a_tuple) # revealed: tuple[int]
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reveal_type(C.a_range) # revealed: range
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reveal_type(C.a_slice) # revealed: slice
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reveal_type(C.a_memoryview) # revealed: memoryview
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reveal_type(C.a_type) # revealed: type
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reveal_type(C.a_none) # revealed: None
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```
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## References
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Some of the tests in the *Class and instance variables* section draw inspiration from
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@@ -0,0 +1,73 @@
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# `inspect.getattr_static`
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`inspect.getattr_static` is a function that returns attributes of an object without invoking the
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descriptor protocol (for caveats, see the [official documentation]).
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Consider the following example:
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```py
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import inspect
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class Descriptor:
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def __get__(self, instance, owner) -> str:
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return 1
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class C:
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normal: int = 1
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descriptor: Descriptor = Descriptor()
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```
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If we access attributes on an instance of `C` as usual, the descriptor protocol is invoked, and we
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get a type of `str` for the `descriptor` attribute:
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```py
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c = C()
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reveal_type(c.normal) # revealed: int
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reveal_type(c.descriptor) # revealed: str
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```
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However, if we use `inspect.getattr_static`, we can see the underlying `Descriptor` type:
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```py
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reveal_type(inspect.getattr_static(c, "normal")) # revealed: int
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reveal_type(inspect.getattr_static(c, "descriptor")) # revealed: Descriptor
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```
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For non-existent attributes, a default value can be provided:
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```py
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reveal_type(inspect.getattr_static(C, "normal", "default-arg")) # revealed: int
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reveal_type(inspect.getattr_static(C, "non_existent", "default-arg")) # revealed: Literal["default-arg"]
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```
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When a non-existent attribute is accessed without a default value, the runtime raises an
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`AttributeError`. We could emit a diagnostic for this case, but that is currently not supported:
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```py
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# TODO: we could emit a diagnostic here
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reveal_type(inspect.getattr_static(C, "non_existent")) # revealed: Never
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```
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We can access attributes on objects of all kinds:
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```py
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import sys
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reveal_type(inspect.getattr_static(sys, "platform")) # revealed: LiteralString
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reveal_type(inspect.getattr_static(inspect, "getattr_static")) # revealed: Literal[getattr_static]
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reveal_type(inspect.getattr_static(1, "real")) # revealed: Literal[1]
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```
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(Implicit) instance attributes can also be accessed through `inspect.getattr_static`:
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```py
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class D:
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def __init__(self) -> None:
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self.instance_attr: int = 1
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reveal_type(inspect.getattr_static(D(), "instance_attr")) # revealed: int
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```
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[official documentation]: https://docs.python.org/3/library/inspect.html#inspect.getattr_static
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192
crates/red_knot_python_semantic/resources/mdtest/call/methods.md
Normal file
192
crates/red_knot_python_semantic/resources/mdtest/call/methods.md
Normal file
@@ -0,0 +1,192 @@
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# Methods
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## Background: Functions as descriptors
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Say we have a simple class `C` with a function definition `f` inside its body:
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```py
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class C:
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def f(self, x: int) -> str:
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return "a"
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```
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Whenever we access the `f` attribute through the class object itself (`C.f`) or through an instance
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(`C().f`), this access happens via the descriptor protocol. Functions are (non-data) descriptors
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because they implement a `__get__` method. This is crucial in making sure that method calls work as
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expected. In general, the signature of the `__get__` method in the descriptor protocol is
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`__get__(self, instance, owner)`. The `self` argument is the descriptor object itself (`f`). The
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passed value for the `instance` argument depends on whether the attribute is accessed from the class
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object (in which case it is `None`), or from an instance (in which case it is the instance of type
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`C`). The `owner` argument is the class itself (`C` of type `Literal[C]`). To summarize:
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- `C.f` is equivalent to `getattr_static(C, "f").__get__(None, C)`
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- `C().f` is equivalent to `getattr_static(C, "f").__get__(C(), C)`
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Here, `inspect.getattr_static` is used to bypass the descriptor protocol and directly access the
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function attribute. The way the special `__get__` method *on functions* works like is as follows. In
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the former case, if the `instance` attribute is `None`, it simply returns the function itself. In
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the latter case, it returns a *bound method* object:
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```py
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from inspect import getattr_static
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reveal_type(getattr_static(C, "f")) # revealed: Literal[f]
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reveal_type(getattr_static(C, "f").__get__) # revealed: <method-wrapper `__get__` of `f`>
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reveal_type(getattr_static(C, "f").__get__(None, C)) # revealed: Literal[f]
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reveal_type(getattr_static(C, "f").__get__(C(), C)) # revealed: <bound method `f` of `C`>
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```
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In conclusion, this is why we see the following two types when accessing the `f` attribute on the
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class object `C` and on an instance `C()`:
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```py
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reveal_type(C.f) # revealed: Literal[f]
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reveal_type(C().f) # revealed: <bound method `f` of `C`>
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```
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A bound method is a callable object that contains a reference to the `instance` that it was called
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on (can be inspected via `__self__`), and the function object that it refers to (can be inspected
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via `__func__`):
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```py
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bound_method = C().f
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reveal_type(bound_method.__self__) # revealed: C
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reveal_type(bound_method.__func__) # revealed: Literal[f]
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```
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When we call the bound method, the `instance` is implicitly passed as the first argument (`self`):
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```py
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reveal_type(C().f(1)) # revealed: str
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reveal_type(bound_method(1)) # revealed: str
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```
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When we call the function object itself, we need to pass the `instance` explicitly:
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```py
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C.f(1) # error: [missing-argument]
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reveal_type(C.f(C(), 1)) # revealed: str
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```
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When we access methods from derived classes, they will be bound to instances of the derived class:
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```py
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class D(C):
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pass
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reveal_type(D().f) # revealed: <bound method `f` of `D`>
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```
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If we access an attribute on a bound method object itself, it will defer to `types.MethodType`:
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```py
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reveal_type(bound_method.__hash__) # revealed: <bound method `__hash__` of `MethodType`>
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```
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## Basic method calls on class objects and instances
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```py
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class Base:
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def method_on_base(self, x: int | None) -> str:
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return "a"
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class Derived(Base):
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def method_on_derived(self, x: bytes) -> tuple[int, str]:
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return (1, "a")
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reveal_type(Base().method_on_base(1)) # revealed: str
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reveal_type(Base.method_on_base(Base(), 1)) # revealed: str
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Base().method_on_base("incorrect") # error: [invalid-argument-type]
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Base().method_on_base() # error: [missing-argument]
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Base().method_on_base(1, 2) # error: [too-many-positional-arguments]
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reveal_type(Derived().method_on_base(1)) # revealed: str
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reveal_type(Derived().method_on_derived(b"abc")) # revealed: tuple[int, str]
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reveal_type(Derived.method_on_base(Derived(), 1)) # revealed: str
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reveal_type(Derived.method_on_derived(Derived(), b"abc")) # revealed: tuple[int, str]
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```
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## Method calls on literals
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### Boolean literals
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```py
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reveal_type(True.bit_length()) # revealed: int
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reveal_type(True.as_integer_ratio()) # revealed: tuple[int, Literal[1]]
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```
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### Integer literals
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```py
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reveal_type((42).bit_length()) # revealed: int
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```
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### String literals
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```py
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reveal_type("abcde".find("abc")) # revealed: int
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reveal_type("foo".encode(encoding="utf-8")) # revealed: bytes
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"abcde".find(123) # error: [invalid-argument-type]
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```
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### Bytes literals
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```py
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reveal_type(b"abcde".startswith(b"abc")) # revealed: bool
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```
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## Method calls on `LiteralString`
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```py
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from typing_extensions import LiteralString
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def f(s: LiteralString) -> None:
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reveal_type(s.find("a")) # revealed: int
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```
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## Method calls on `tuple`
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```py
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def f(t: tuple[int, str]) -> None:
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reveal_type(t.index("a")) # revealed: int
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```
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## Method calls on unions
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```py
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from typing import Any
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class A:
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def f(self) -> int:
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return 1
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class B:
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def f(self) -> str:
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return "a"
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def f(a_or_b: A | B, any_or_a: Any | A):
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reveal_type(a_or_b.f) # revealed: <bound method `f` of `A`> | <bound method `f` of `B`>
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reveal_type(a_or_b.f()) # revealed: int | str
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reveal_type(any_or_a.f) # revealed: Any | <bound method `f` of `A`>
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reveal_type(any_or_a.f()) # revealed: Any | int
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```
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## Method calls on `KnownInstance` types
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```toml
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[environment]
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python-version = "3.12"
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```
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```py
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type IntOrStr = int | str
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reveal_type(IntOrStr.__or__) # revealed: <bound method `__or__` of `typing.TypeAliasType`>
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```
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@@ -22,22 +22,25 @@ class Ten:
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pass
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class C:
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ten = Ten()
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ten: Ten = Ten()
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c = C()
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# TODO: this should be `Literal[10]`
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reveal_type(c.ten) # revealed: Unknown | Ten
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reveal_type(c.ten) # revealed: Literal[10]
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# TODO: This should `Literal[10]`
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reveal_type(C.ten) # revealed: Unknown | Ten
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reveal_type(C.ten) # revealed: Literal[10]
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# These are fine:
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c.ten = 10
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# TODO: This should not be an error
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c.ten = 10 # error: [invalid-assignment]
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C.ten = 10
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# TODO: Both of these should be errors
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# TODO: This should be an error, but the message needs to be improved.
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# error: [invalid-assignment] "Object of type `Literal[11]` is not assignable to attribute `ten` of type `Ten`"
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c.ten = 11
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# TODO: This should be an error, but the message needs to be improved.
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# error: [invalid-assignment] "Object of type `Literal[11]` is not assignable to attribute `ten` of type `Literal[10]`"
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C.ten = 11
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```
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@@ -57,24 +60,84 @@ class FlexibleInt:
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self._value = int(value)
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class C:
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flexible_int = FlexibleInt()
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flexible_int: FlexibleInt = FlexibleInt()
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c = C()
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# TODO: should be `int | None`
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reveal_type(c.flexible_int) # revealed: Unknown | FlexibleInt
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reveal_type(c.flexible_int) # revealed: int | None
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# TODO: These should not be errors
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# error: [invalid-assignment]
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c.flexible_int = 42 # okay
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# error: [invalid-assignment]
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c.flexible_int = "42" # also okay!
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# TODO: should be `int | None`
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reveal_type(c.flexible_int) # revealed: Unknown | FlexibleInt
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reveal_type(c.flexible_int) # revealed: int | None
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# TODO: should be an error
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# TODO: This should be an error, but the message needs to be improved.
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# error: [invalid-assignment] "Object of type `None` is not assignable to attribute `flexible_int` of type `FlexibleInt`"
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c.flexible_int = None # not okay
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# TODO: should be `int | None`
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reveal_type(c.flexible_int) # revealed: Unknown | FlexibleInt
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reveal_type(c.flexible_int) # revealed: int | None
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```
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## Data and non-data descriptors
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Descriptors that define `__set__` or `__delete__` are called *data descriptors* (e.g. properties),
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while those that only define `__get__` are called non-data descriptors (e.g. functions,
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`classmethod` or `staticmethod`).
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The precedence chain for attribute access is (1) data descriptors, (2) instance attributes, and (3)
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non-data descriptors.
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|
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```py
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from typing import Literal
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|
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class DataDescriptor:
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def __get__(self, instance: object, owner: type | None = None) -> Literal["data"]:
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return "data"
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def __set__(self, instance: int, value) -> None:
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pass
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class NonDataDescriptor:
|
||||
def __get__(self, instance: object, owner: type | None = None) -> Literal["non-data"]:
|
||||
return "non-data"
|
||||
|
||||
class C:
|
||||
data_descriptor = DataDescriptor()
|
||||
non_data_descriptor = NonDataDescriptor()
|
||||
|
||||
def f(self):
|
||||
# This explains why data descriptors come first in the precendence chain. If
|
||||
# instance attributes would take priority, we would override the descriptor
|
||||
# here. Instead, this calls `DataDescriptor.__set__`, i.e. it does not affect
|
||||
# the type of the `data_descriptor` attribute.
|
||||
self.data_descriptor = 1
|
||||
|
||||
# However, for non-data descriptors, instance attributes do take precedence.
|
||||
# So it is possible to override them.
|
||||
self.non_data_descriptor = 1
|
||||
|
||||
c = C()
|
||||
|
||||
# TODO: This should ideally be `Unknown | Literal["data"]`.
|
||||
#
|
||||
# - Pyright also wrongly shows `int | Literal['data']` here
|
||||
# - Mypy shows Literal["data"] here, but also shows Literal["non-data"] below.
|
||||
#
|
||||
reveal_type(c.data_descriptor) # revealed: Unknown | Literal["data", 1]
|
||||
|
||||
reveal_type(c.non_data_descriptor) # revealed: Unknown | Literal["non-data", 1]
|
||||
|
||||
reveal_type(C.data_descriptor) # revealed: Unknown | Literal["data"]
|
||||
|
||||
reveal_type(C.non_data_descriptor) # revealed: Unknown | Literal["non-data"]
|
||||
|
||||
# It is possible to override data descriptors via class objects. The following
|
||||
# assignment does not call `DataDescriptor.__set__`. For this reason, we infer
|
||||
# `Unknown | …` for all (descriptor) attributes.
|
||||
C.data_descriptor = "something else" # This is okay
|
||||
```
|
||||
|
||||
## Built-in `property` descriptor
|
||||
@@ -101,7 +164,7 @@ c = C()
|
||||
reveal_type(c._name) # revealed: str | None
|
||||
|
||||
# Should be `str`
|
||||
reveal_type(c.name) # revealed: @Todo(bound method)
|
||||
reveal_type(c.name) # revealed: @Todo(decorated method)
|
||||
|
||||
# Should be `builtins.property`
|
||||
reveal_type(C.name) # revealed: Literal[name]
|
||||
@@ -142,7 +205,7 @@ reveal_type(c1) # revealed: @Todo(return type)
|
||||
reveal_type(C.get_name()) # revealed: @Todo(return type)
|
||||
|
||||
# TODO: should be `str`
|
||||
reveal_type(C("42").get_name()) # revealed: @Todo(bound method)
|
||||
reveal_type(C("42").get_name()) # revealed: @Todo(decorated method)
|
||||
```
|
||||
|
||||
## Descriptors only work when used as class variables
|
||||
@@ -160,9 +223,10 @@ class Ten:
|
||||
|
||||
class C:
|
||||
def __init__(self):
|
||||
self.ten = Ten()
|
||||
self.ten: Ten = Ten()
|
||||
|
||||
reveal_type(C().ten) # revealed: Unknown | Ten
|
||||
# TODO: Should be Ten
|
||||
reveal_type(C().ten) # revealed: Literal[10]
|
||||
```
|
||||
|
||||
## Descriptors distinguishing between class and instance access
|
||||
@@ -186,13 +250,115 @@ class Descriptor:
|
||||
return "called on class object"
|
||||
|
||||
class C:
|
||||
d = Descriptor()
|
||||
d: Descriptor = Descriptor()
|
||||
|
||||
# TODO: should be `Literal["called on class object"]
|
||||
reveal_type(C.d) # revealed: Unknown | Descriptor
|
||||
reveal_type(C.d) # revealed: LiteralString
|
||||
|
||||
# TODO: should be `Literal["called on instance"]
|
||||
reveal_type(C().d) # revealed: Unknown | Descriptor
|
||||
reveal_type(C().d) # revealed: LiteralString
|
||||
```
|
||||
|
||||
## Undeclared descriptor arguments
|
||||
|
||||
If a descriptor attribute is not declared, we union with `Unknown`, just like for regular
|
||||
attributes, since that attribute could be overwritten externally. Even data-descriptors with a
|
||||
`__set__` method can be overwritten when accessed through a class object.
|
||||
|
||||
```py
|
||||
class Descriptor:
|
||||
def __get__(self, instance: object, owner: type | None = None) -> int:
|
||||
return 1
|
||||
|
||||
def __set__(self, instance: object, value: int) -> None:
|
||||
pass
|
||||
|
||||
class C:
|
||||
descriptor = Descriptor()
|
||||
|
||||
C.descriptor = "something else"
|
||||
|
||||
reveal_type(C.descriptor) # revealed: Unknown | int
|
||||
```
|
||||
|
||||
## Descriptors with incorrect `__get__` signature
|
||||
|
||||
```py
|
||||
class Descriptor:
|
||||
# `__get__` method with missing parameters:
|
||||
def __get__(self) -> int:
|
||||
return 1
|
||||
|
||||
class C:
|
||||
descriptor: Descriptor = Descriptor()
|
||||
|
||||
# TODO: This should be an error
|
||||
reveal_type(C.descriptor) # revealed: Descriptor
|
||||
```
|
||||
|
||||
## Possibly-unbound `__get__` method
|
||||
|
||||
```py
|
||||
def _(flag: bool):
|
||||
class MaybeDescriptor:
|
||||
if flag:
|
||||
def __get__(self, instance: object, owner: type | None = None) -> int:
|
||||
return 1
|
||||
|
||||
class C:
|
||||
descriptor: MaybeDescriptor = MaybeDescriptor()
|
||||
|
||||
# TODO: This should be `MaybeDescriptor | int`
|
||||
reveal_type(C.descriptor) # revealed: int
|
||||
```
|
||||
|
||||
## Dunder methods
|
||||
|
||||
Dunder methods are looked up on the meta type, but we still need to invoke the descriptor protocol:
|
||||
|
||||
```py
|
||||
class SomeCallable:
|
||||
def __call__(self, x: int) -> str:
|
||||
return "a"
|
||||
|
||||
class Descriptor:
|
||||
def __get__(self, instance: object, owner: type | None = None) -> SomeCallable:
|
||||
return SomeCallable()
|
||||
|
||||
class B:
|
||||
__call__: Descriptor = Descriptor()
|
||||
|
||||
b_instance = B()
|
||||
reveal_type(b_instance(1)) # revealed: str
|
||||
|
||||
b_instance("bla") # error: [invalid-argument-type]
|
||||
```
|
||||
|
||||
## Functions as descriptors
|
||||
|
||||
Functions are descriptors because they implement a `__get__` method. This is crucial in making sure
|
||||
that method calls work as expected. See [this test suite](./call/methods.md) for more information.
|
||||
Here, we only demonstrate how `__get__` works on functions:
|
||||
|
||||
```py
|
||||
from inspect import getattr_static
|
||||
|
||||
def f(x: int) -> str:
|
||||
return "a"
|
||||
|
||||
reveal_type(f) # revealed: Literal[f]
|
||||
reveal_type(f.__get__) # revealed: <method-wrapper `__get__` of `f`>
|
||||
reveal_type(f.__get__(None, f)) # revealed: Literal[f]
|
||||
reveal_type(f.__get__(None, f)(1)) # revealed: str
|
||||
|
||||
reveal_type(getattr_static(f, "__get__")) # revealed: <wrapper-descriptor `__get__` of `function` objects>
|
||||
reveal_type(getattr_static(f, "__get__")(f, None, type(f))) # revealed: Literal[f]
|
||||
|
||||
# Attribute access on the method-wrapper `f.__get__` falls back to `MethodWrapperType`:
|
||||
reveal_type(f.__get__.__hash__) # revealed: <bound method `__hash__` of `MethodWrapperType`>
|
||||
|
||||
# Attribute access on the wrapper-descriptor `getattr_static(f, "__get__")` falls back to `WrapperDescriptorType`:
|
||||
reveal_type(getattr_static(f, "__get__").__qualname__) # revealed: @Todo(@property)
|
||||
```
|
||||
|
||||
[descriptors]: https://docs.python.org/3/howto/descriptor.html
|
||||
|
||||
@@ -9,7 +9,7 @@ is unbound.
|
||||
```py
|
||||
reveal_type(__name__) # revealed: str
|
||||
reveal_type(__file__) # revealed: str | None
|
||||
reveal_type(__loader__) # revealed: LoaderProtocol | None
|
||||
reveal_type(__loader__) # revealed: @Todo(instance attribute on class with dynamic base) | None
|
||||
reveal_type(__package__) # revealed: str | None
|
||||
reveal_type(__doc__) # revealed: str | None
|
||||
|
||||
@@ -54,10 +54,10 @@ inside the module:
|
||||
import typing
|
||||
|
||||
reveal_type(typing.__name__) # revealed: str
|
||||
reveal_type(typing.__init__) # revealed: @Todo(bound method)
|
||||
reveal_type(typing.__init__) # revealed: <bound method `__init__` of `ModuleType`>
|
||||
|
||||
# These come from `builtins.object`, not `types.ModuleType`:
|
||||
reveal_type(typing.__eq__) # revealed: @Todo(bound method)
|
||||
reveal_type(typing.__eq__) # revealed: <bound method `__eq__` of `ModuleType`>
|
||||
|
||||
reveal_type(typing.__class__) # revealed: Literal[ModuleType]
|
||||
|
||||
|
||||
@@ -66,6 +66,6 @@ It is [recommended](https://docs.python.org/3/library/sys.html#sys.platform) to
|
||||
```py
|
||||
import sys
|
||||
|
||||
reveal_type(sys.platform.startswith("freebsd")) # revealed: @Todo(Attribute access on `LiteralString` types)
|
||||
reveal_type(sys.platform.startswith("linux")) # revealed: @Todo(Attribute access on `LiteralString` types)
|
||||
reveal_type(sys.platform.startswith("freebsd")) # revealed: bool
|
||||
reveal_type(sys.platform.startswith("linux")) # revealed: bool
|
||||
```
|
||||
|
||||
@@ -35,7 +35,7 @@ in strict mode.
|
||||
```py
|
||||
def f(x: type):
|
||||
reveal_type(x) # revealed: type
|
||||
reveal_type(x.__repr__) # revealed: @Todo(bound method)
|
||||
reveal_type(x.__repr__) # revealed: <bound method `__repr__` of `type`>
|
||||
|
||||
class A: ...
|
||||
|
||||
@@ -50,7 +50,7 @@ x: type = A() # error: [invalid-assignment]
|
||||
```py
|
||||
def f(x: type[object]):
|
||||
reveal_type(x) # revealed: type
|
||||
reveal_type(x.__repr__) # revealed: @Todo(bound method)
|
||||
reveal_type(x.__repr__) # revealed: <bound method `__repr__` of `type`>
|
||||
|
||||
class A: ...
|
||||
|
||||
|
||||
@@ -75,3 +75,19 @@ class Boom:
|
||||
|
||||
reveal_type(bool(Boom())) # revealed: bool
|
||||
```
|
||||
|
||||
### Possibly unbound __bool__ method
|
||||
|
||||
```py
|
||||
from typing import Literal
|
||||
|
||||
def flag() -> bool:
|
||||
return True
|
||||
|
||||
class PossiblyUnboundTrue:
|
||||
if flag():
|
||||
def __bool__(self) -> Literal[True]:
|
||||
return True
|
||||
|
||||
reveal_type(bool(PossiblyUnboundTrue())) # revealed: bool
|
||||
```
|
||||
|
||||
Reference in New Issue
Block a user