Typeshed contains external type annotations 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.
For information on how to use
typeshed, read below. Information for
contributors can be found in CONTRIBUTING.md. Please read
it before submitting pull requests.
Typeshed supports Python versions 2.7 and 3.3 and up.
If you're just using mypy (or pytype or PyCharm), as opposed to developing it, you don't need to interact with the typeshed repo at all: a copy of typeshed is bundled with mypy.
When you use a checked-out clone of the mypy repo, a copy of typeshed should be included as a submodule, using
$ git clone --recurse-submodules https://github.com/python/mypy.git
$ git clone https://github.com/python/mypy.git $ cd mypy $ git submodule init $ git submodule update
and occasionally you will have to repeat the final command (
git submodule update) to pull in changes made in the upstream typeshed
PyCharm and pytype similarly include a copy of typeshed. The one in pytype can be updated in the same way if you are working with the pytype repo.
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.
The below is an excerpt from the types for the
from typing import Union MAXYEAR = ... # type: int MINYEAR = ... # type: int class date(object): def __init__(self, year: int, month: int, day: int) -> None: ... @classmethod def fromtimestamp(cls, timestamp: Union[int, float]) -> date: ... @classmethod def fromordinal(cls, ordinal: int) -> date: ... @classmethod def today(self) -> date: ... def ctime(self) -> str: ... def weekday(self) -> int: ...
This contains stubs for modules the Python standard library -- which includes pure Python modules, dynamically loaded extension modules, hard-linked extension modules, and the builtins.
Modules that are not shipped with Python but have a type description in Python
third_party. Since these modules can behave differently for different
versions of Python,
third_party has version subdirectories, just like
NOTE: When you're contributing a new stub for a package that you did not develop, please obtain consent of the package owner (this is specified in PEP 484). The best way to obtain consent is to file an issue in the third-party package's tracker and include the link to a positive response in your PR for typeshed.
For more information on directory structure and stub versioning, see the relevant section of CONTRIBUTING.md.
Running the tests
The tests are automatically run by Travis CI on every PR and push to
the repo. There are several sets of tests:
runs tests against mypy, while
tests/pytype_test.py runs tests against
Both sets of tests are shallow -- they verify that all stubs can be imported but they don't check whether stubs match their implementation (in the Python standard library or a third-party package). Also note that each set of tests has a blacklist of modules that are not tested at all. The blacklists also live in the tests directory.
In addition, you can run
tests/mypy_selftest.py to run mypy's own
test suite using the typeshed code in your repo. This will sometimes
catch issues with incorrectly typed stubs, but is much slower than the
To manually run the mypy tests, you need to have Python 3.5 or higher; Python 3.6.1 or higher is recommended.
$ python3.6 -m venv .venv3 $ source .venv3/bin/activate (.venv3)$ pip3 install -r requirements-tests-py3.txt
This will install mypy (you need the latest master branch from GitHub), typed-ast, and flake8. You can then run mypy tests and flake8 tests by invoking:
(.venv3)$ python3 tests/mypy_test.py ... (.venv3)$ python3 tests/mypy_selftest.py ... (.venv3)$ flake8 ...
(Note that flake8 only works with Python 3.6 or higher.)
To run the pytype tests, you need a separate virtual environment with Python 2.7. Run:
$ virtualenv --python=python2.7 .venv2 $ source .venv2/bin/activate (.venv2)$ pip install -r requirements-tests-py2.txt
This will install pytype from its GitHub repo. You can then run pytype tests by running:
(.venv2)$ python tests/pytype_test.py
For mypy, if you are in the typeshed repo that is submodule of the
mypy repo (so
.. refers to the mypy repo), there's a shortcut to run
the mypy tests that avoids installing mypy:
$ PYTHONPATH=.. python3 tests/mypy_test.py
You can mypy tests to a single version by passing
$ PYTHONPATH=.. python3 tests/mypy_test.py -p3.5 running mypy --python-version 3.5 --strict-optional # with 342 files