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.
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 datetime
module.
MAXYEAR = ... # type: int
MINYEAR = ... # type: int
class date(object):
def __init__(self, year: int, month: int, day: int) -> None: ...
@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: ...
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
go into third_party
. Since these modules can behave differently for different
versions of Python, third_party
has version subdirectories, just like
stdlib
.
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.
Please read CONTRIBUTING.md before submitting pull requests.
The tests are automatically run by Travis CI on every PR and push to
the repo. There are two separate sets of tests: tests/mypy_test.py
runs tests against mypy, while
tests/pytype_tests.py
runs tests against
pytype.
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.
To manually run the mypy tests, you need to have Python 3.5 or higher; Python 3.6.1 or higher is recommended. Run:
$ 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)$ 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 -p2
or -p3.5
e.g.
$ PYTHONPATH=.. python3 tests/mypy_test.py -p3.5
running mypy --python-version 3.5 --strict-optional # with 342 files