PEP 484

lastmod 2022-12-21created 2021-02-245 edits

PEP 484 -- Type Hints.

Exceptions

• # type: ignore comment
• @no_type_check decorator on a class or function
• Custom class or Function decorator marked with @no_type_check_decorator

Stub Files

• PEP 484 – Type Hints | peps.python.org # Stub Files

Stub files are files containing type hints that are only for use by the type checker, not at runtime. There are several use cases for stub files:

• Extension modules
• Third-party modules whose authors have not yet added type hints
• Standard library modules for which type hints have not yet been written
• Modules that must be compatible with Python 2 and 3
• Modules that use annotations for other purposes

How to create them

• python - Create .pyi files automatically? - Stack Overflow

Simply, if mypy is installed:

mkdir out
stubgen -m cv2 -o out

See mypy:stubgen for details.

Other libraries include:

• make-stub-files
• Typeshed

This is typically used when PyCharm cannot find cv2 symbols.

See also

• Python
• mypy

Favorite site

• PEP 484 -- Type Hints