typeshed

About

Typeshed models function types for the Python standard library and Python builtins, as well as third party packages.

This data can e.g. be used for static analysis, type checking or type inference.

Format

Each Python module is represented by a .pyi "stub". This is a normal Python file (i.e., it can be interpreted by Python 3), except all the methods are empty. Python function annotations (PEP 3107) are used to describe the types the function has. See PEP 484 for the exact syntax of the stub files.

Directory structure

We store stubs for both Python 2 as well as Python 3. We also distinguish between minor versions (E.g. 3.2 <-> 3.3). To accomplish not having to duplicate modules that are the same between all minor versions, we have e.g. a top-level directory 3/ that contains all the stubs for Python 3. More specialized stubs go into e.g. 3.3/ and supersede the more generic stubs in 3/. (And, if needed, a directory 3.3.1/ would be able to supersede stubs in 3.3/):

Directory
2.7/	Stubs for Python 2.7
3/	Stubs for Python 3
3.3/	Some specialized stubs for Python 3.3 (replacing generic stubs in 3/)

Example

The below is an excerpt from the types for the datetime module.

MAXYEAR = ...  # type: int
MINYEAR = ...  # type: int
__doc__ = ...  # type: str
__file__ = ...  # type: str
__name__ = ...  # type: str
__package__ = ...  # type: None

class date(object):
    def __init__(self, year: int, month: int, day: int): ...
    @classmethod
    def fromtimestamp(cls, timestamp: int or float) -> date: ...
    @classmethod
    def fromordinal(cls, ordinal: int) -> date: ...
    @classmethod
    def today(self) -> date: ...
    def ctime(self) -> str: ...
    def weekday(self) -> int: ...

Contributions

We're welcoming contributions (pull requests) for types of third party packages. They'll go under {2.7,3}/dist-packages/.