Replace typing_extensions -> typing in examples (#1987)

Author: smheidrich

docs/guides/unreachable.rst

@@ -54,7 +54,7 @@ As an example, consider this simple calculator:
 .. code:: python
 
    import enum
-   from typing_extensions import Never
+   from typing import Never
 
    def assert_never(arg: Never) -> Never:
        raise AssertionError("Expected code to be unreachable")
@@ -72,6 +72,11 @@ As an example, consider this simple calculator:
            case _:
                assert_never(op)
 
+.. note::
+
+   To use this feature on Python versions earlier than 3.11, you will need to
+   import ``Never`` from ``typing_extensions`` (version 4.1 or newer).
+
 The ``match`` statement covers all members of the ``Op`` enum,
 so the ``assert_never()`` call is unreachable and the type checker
 will accept this code. However, if you add another member to the

docs/reference/generics.rst

@@ -651,8 +651,7 @@ for a more faithful type annotation:
 
 .. code-block:: python
 
-   from typing import Callable, TypeVar
-   from typing_extensions import ParamSpec
+   from typing import Callable, ParamSpec, TypeVar
 
    P = ParamSpec('P')
    T = TypeVar('T')
@@ -663,13 +662,17 @@ for a more faithful type annotation:
            return func(*args, **kwds)
        return wrapper
 
+.. note::
+
+   To use this feature on Python versions earlier than 3.10, you will need to
+   import ``ParamSpec`` and ``Concatenate`` from ``typing_extensions``.
+
 Parameter specifications also allow you to describe decorators that
 alter the signature of the input function:
 
 .. code-block:: python
 
-   from typing import Callable, TypeVar
-   from typing_extensions import ParamSpec
+   from typing import Callable, ParamSpec, TypeVar
 
    P = ParamSpec('P')
    T = TypeVar('T')
@@ -692,8 +695,7 @@ Or insert an argument:
 
 .. code-block:: python
 
-    from typing import Callable, TypeVar
-    from typing_extensions import Concatenate, ParamSpec
+    from typing import Callable, Concatenate, ParamSpec, TypeVar
 
     P = ParamSpec('P')
     T = TypeVar('T')
@@ -774,8 +776,7 @@ Example:
 
 .. code-block:: python
 
-   from typing import TypeVar
-   from typing_extensions import Protocol
+   from typing import Protocol, TypeVar
 
    T = TypeVar('T')
 

docs/reference/protocols.rst

@@ -71,8 +71,7 @@ You can define your own protocol class by inheriting from the special
 
 .. code-block:: python
 
-   from typing import Iterable
-   from typing_extensions import Protocol
+   from typing import Iterable, Protocol
 
    class SupportsClose(Protocol):
        # Empty method body (explicit '...')
@@ -231,8 +230,7 @@ such as trees and linked lists:
 
 .. code-block:: python
 
-   from typing import TypeVar, Optional
-   from typing_extensions import Protocol
+   from typing import TypeVar, Optional, Protocol
 
    class TreeLike(Protocol):
        value: int
@@ -260,7 +258,7 @@ rudimentary support for runtime structural checks:
 
 .. code-block:: python
 
-   from typing_extensions import Protocol, runtime_checkable
+   from typing import Protocol, runtime_checkable
 
    @runtime_checkable
    class Portable(Protocol):
@@ -303,8 +301,7 @@ member:
 
 .. code-block:: python
 
-   from typing import Optional, Iterable
-   from typing_extensions import Protocol
+   from typing import Optional, Iterable, Protocol
 
    class Combiner(Protocol):
        def __call__(self, *vals: bytes, maxlen: Optional[int] = None) -> list[bytes]: ...
@@ -328,8 +325,7 @@ a double underscore prefix is used. For example:
 
 .. code-block:: python
 
-   from typing import Callable, TypeVar
-   from typing_extensions import Protocol
+   from typing import Callable, TypeVar, Protocol
 
    T = TypeVar('T')
 

docs/reference/quality.rst

@@ -40,10 +40,15 @@ then the following file tests ``foo.py``:
 
 .. code-block:: python
 
-    from typing_extensions import assert_type
+    from typing import assert_type
 
     assert_type(bar(42), str)
 
+.. note::
+
+   To use this feature on Python versions earlier than 3.11, you will need to
+   import ``assert_type`` from ``typing_extensions`` (version 4.2 or newer).
+
 Clever use of ``mypy --warn-unused-ignores`` can be used to check that certain
 expressions are or are not well-typed. The idea is to have valid expressions along
 with invalid expressions annotated with ``type: ignore`` comments. When