typeshed
About
Typeshed contains external type annotations for the Python standard library and Python builtins, as well as third party packages as contributed by people external to those projects.
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; do not report issues with annotations to
the project the stubs are for, but instead report them here to typeshed.
Typeshed supports Python versions 2.7 and 3.5 and up.
Using
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
or
$ 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
repo.
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.
Format
Each Python module is represented by a .pyi
"stub file". This is a
syntactically valid Python file, although it usually cannot be run by
Python 3 (since forward references don't require string quotes). All
the methods are empty.
Python function annotations (PEP 3107) are used to describe the signature of each function or method.
See PEP 484 for the exact syntax of the stub files and CONTRIBUTING.md for the coding style used in typeshed.
Directory structure
stdlib
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.
third_party
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
.
For more information on directory structure and stub versioning, see the relevant section of CONTRIBUTING.md.
Contributing
Please read CONTRIBUTING.md before submitting pull requests. If you have questions related to contributing, drop by the typing Gitter.
Running the tests
The tests are automatically run by Travis CI on every PR and push to the repo. Note that it can be useful to enable Travis CI on your own fork of typeshed.
There are several tests:
tests/mypy_test.py
runs tests against mypytests/pytype_test.py
runs tests against pytype.tests/mypy_selftest.py
runs mypy's test suite using this version of typeshed.tests/check_consistent.py
checks certain files in typeshed remain consistent with each other.tests/stubtest_test.py
checks stubs against the objects at runtime.flake8
enforces a style guide.
Setup
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, flake8 (and plugins), pytype, black and isort.
mypy_test.py
This test requires Python 3.5 or higher; Python 3.6.1 or higher is recommended.
Run using:(.venv3)$ python3 tests/mypy_test.py
This test is shallow โ it verifies that all stubs can be imported but doesn't check whether stubs match their implementation (in the Python standard library or a third-party package). It has a blacklist of modules that are not tested at all, which also lives in the tests directory.
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 restrict mypy tests to a single version by passing -p2
or -p3.5
:
$ PYTHONPATH=../.. python3 tests/mypy_test.py -p3.5
running mypy --python-version 3.5 --strict-optional # with 342 files
pytype_test.py
This test requires Python 2.7 and Python 3.6. Pytype will
find these automatically if they're in PATH
, but otherwise you must point to
them with the --python27-exe
and --python36-exe
arguments, respectively.
Run using: (.venv3)$ python3 tests/pytype_test.py
This test works similarly to mypy_test.py
, except it uses pytype
.
mypy_selftest.py
This test requires Python 3.5 or higher; Python 3.6.1 or higher is recommended.
Run using: (.venv3)$ python3 tests/mypy_selftest.py
This test runs 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 other tests.
check_consistent.py
Run using: python3 tests/check_consistent.py
stubtest_test.py
This test requires Python 3.5 or higher.
Run using (.venv3)$ python3 tests/stubtest_test.py
This test compares the stdlib stubs against the objects at runtime. Because of this, the output depends on which version of Python it is run with. If you need a specific version of Python to repro a CI failure, pyenv can help (as can enabling Travis CI on your fork).
Due to its dynamic nature, you may run into false positives. In this case, you
can add to the whitelists for each affected Python version in
tests/stubtest_whitelists
. Please file issues for stubtest false positives
at mypy.
To run stubtest against third party stubs, it's easiest to use stubtest directly. stubtest can also help you find things missing from the stubs.
flake8
flake8 requires Python 3.6 or higher. Run using: (.venv3)$ flake8
Note typeshed uses the flake8-pyi
and flake8-bugbear
plugins.