Want to contribute? Great! First, read this page (including the small print at the end).
Before we can use your code, you must sign the Google Individual Contributor License Agreement (CLA), which you can do online. The CLA is necessary mainly because you own the copyright to your changes, even after your contribution becomes part of our codebase, so we need your permission to use and distribute your code. We also need to be sure of various other things -- for instance that you'll tell us if you know that your code infringes on other people's patents. You don't have to sign the CLA until after you've submitted your code for review and a member has approved it, but you must do it before we can put your code into our codebase. Before you start working on a larger contribution, you should get in touch with us first through the issue tracker with your idea so that we can help out and possibly guide you. Coordinating up front makes it much easier to avoid frustration later on.
All submissions, including submissions by project members, require review. We use Github pull requests for this purpose.
Before you can build and test Pytype, you will have to install a few dependencies.
- A C++11 compiler for your platform: Pytype uses extension modules. A C++11 compiler is required to build these extension modules.
- CMake version 2.8 or higher: To build the extension modules and to run tests in parallel, Pytype makes use of a CMake based build system.
- Bison version 3.0.2 or higher: Pytype uses a custom parser to parse PYI files. This parser is implemented using Flex and Bison.
- Flex version 2.5.35 or higher
- ninja build: Pytype's test utility scripts make use of ninja as the CMake generated build system. NOTE: if you have a ninja Python distribution installed and active, you can skip installing the official ninja distribution.
- Python2.7 and Python3.x Interpreters: A large subset of Pytype's functional tests analyse the target (the Python source code that is being analyzed by Pytype) twice: once as if it were Python2.7 code, and another time as if it were in the Python 3.x version that pytype is running under. Hence, to run these tests, you will need Python 2.7 and Python 3.x (preferably 3.6+) interpreters installed on your system.
Required Python packages are listed in the requirements.txt file in this repository. They can be installed with pip with the following command:
pip install -r requirements.txt
The Pytype Git repository also contains few Git submodules. Before building
the pytype
executable or running tests, one has to ensure that the submodules
are up to date. This can be done with the following command:
git submodule update --init
There are two ways to build the executables like pytype
etc. To build them the
same way that the continuous integration tests do, use this convenience script:
python build_scripts/build.py
build.py
will build the executables in the out/bin
directory.
To emulate the way they are built when a user downloads the source code from PyPI, use:
pip install -e .
-e
makes it so that the executables will automatically pick up code edits.
This second method is useful for making sure that pytype is still packaged
correctly after changes to its code structure or dependencies. The downside is
that logging from extension modules is unavailable (see below).
One can pass the logging verbosity level option to pytype-single
to see the
logs:
out/bin/pytype-single -v<N> <other command like arguments>
For information about the logging levels, run pytype-single --help
.
The pytype-single
executable makes use of few a C extension modules. Logging
from these extension modules is enabled only in debug builds. One can build
pytype-single
in debug mode by passing the --debug
option to the build
script as follows:
python build_scripts/build.py --debug
In a debug build of pytype-single
, logging from extension modules follows the
same verbosity levels as the rest of the Python modules.
Ideally, every change should include a test. Depending on the type of your
change, you should either be adding a functional test or a unit test (some
changes might warrant both). Functional tests should be added in the
pytype/tests
directory. Unit tests should be added in a test module next to
the module that is being tested.
Since Pytype already has exhaustive tests, a change will most likely need to
add a test method to an existing test module. In such a case, there is
nothing special required, other than just adding a new test method. If adding a
new test module is more meaningful, apart from adding the new test module, your
change should also add a py_test
target to the CMakeLists.txt
file in the
directory in which the test module lives. See existing py_test
targets (in
CMakeLists.txt
files) for examples on how to do this.
NOTE: Please see pytype/tests/README.md
for more rules pertaining to adding
new functional tests.
There exists a convenience script to run Pytype tests. A typical usage of this script is as follows:
python build_scripts/run_tests.py <TARGET>
TARGET
is the fully qualified name of the test target within the root Pytype
source tree. If a target name is not specified, the script runs all py_test
and cc_test
targets in the Pytype source tree.
For more information about run_tests.py
options, run run_test.py --help
.
To also lint and type-check the code, you can use:
python build_scripts/ci_script.py
For more resources for contributors, check out our developer guide: https://google.github.io/pytype/developers/index.html.
Contributions made by corporations are covered by a different agreement than the one mentioned above; they're covered by the Software Grant and Corporate Contributor License Agreement.