gnychis / typing

typing: Type Hints for Python

What Is typing?

This is a backport of the typing module introduced in Python 3.5 beta 1 to Python 3.2, 3.3 and 3.4. The eventual goal is to also provide a stripped-down implementation for Python 2.7. typing allows you to add type annotations to your code in a standard format that will be understood by static type checkers and IDEs.

Here is a small example:

from typing import Iterator

def fib(n: int) -> Iterator[int]:
    a, b = 0, 1
    while a < n:
        yield a
        a, b = b, a + b

Documentation about typing in general is hosted everywhere (see the links below).

Status

This is work in progress. The typing module may still undergo small changes before Python 3.5 is finalized.

The Python 2 version is woefully out of date.

Useful Links

• https://www.python.org/dev/peps/pep-0484/: PEP 484 is a specification of the typing module.
• https://github.com/ambv/typehinting: Discussion about future improvements to typing happen here. If you want to contribute a new feature or fix that is not specific to pre-3.5 Python version, do it here.
• https://github.com/JukkaL/mypy: Mypy is a type checker that aims to conform to PEP 484.

License

Since typing is lifted from Python 3.5, it's distributed under the PSF license. The current Python 2 version (which does not conform to PEP 484 yet) is distributed under the MIT license, but it will be replaced by a version that is derived from the Python 3.5 version soon.