15 lines
762 B
Text
15 lines
762 B
Text
This was originally a backport of the standard library 'typing' module to
|
|
Python versions older than 3.5.
|
|
|
|
Typing defines a standard notation for Python function and variable type
|
|
annotations. The notation can be used for documenting code in a concise,
|
|
standard format, and it has been designed to also be used by static and runtime
|
|
type checkers, static analyzers, IDEs and other tools.
|
|
|
|
Today, 'typing_extensions' serves two related purposes:
|
|
|
|
- Enable use of new type system features on older Python versions. For example,
|
|
'typing.TypeGuard' is new in Python 3.10, but 'typing_extensions' allows
|
|
users on Python 3.6 through 3.9 to use it too.
|
|
- Enable experimentation with new type system PEPs before they are accepted and
|
|
added to the 'typing' module.
|