typing - Support for type hints - Python 3.8.6rc1 documentation
Source code: Lib/typing.py Note The Python runtime does not enforce function and variable type annotations. They can be used by third party tools such as type checkers, IDEs, linters, etc. The function below takes and returns a string and is annotated as follows: In the function , the argument is expected to be of type and the return type .
https://docs.python.org/3/library/typing.html
