a type inferencer for Python

pushedAt 2 years ago


PySonar2 - a type inferencer for Python

PySonar2 is a type inferencer for Python. It performs whole-project interprocedural analysis to infer types.

Get the code

git clone https://github.com/yinwang0/pysonar2.git
git checkout tags/v2.1.1

How to build

mvn package

How to use

You can build a simple "code-browser" of the Python 2.7 standard library with the following command line:

java -jar target/pysonar-<version>.jar /usr/lib/python2.7 ./html

This will take a few minutes. You should find some interactive HTML files inside the html directory after this process.

Note that this is just a demo program. PySonar2 is not an end-user tool. It is mainly designed as a library for Python IDEs, other developer tools and code search engines, so its interface may not be as appealing as an end-user tool.

System requirements

  • Python 2.7.x
  • Python 3.x
  • Java 8
  • maven

Environment variables

PySonar2 uses CPython's ast package to parse Python code, so please make sure you have python or python3 installed and pointed to by the PATH environment variable. If you have them in different names, please make symbol links.

PYTHONPATH environment variable is used for locating the Python standard libraries. It is important to point it to the correct Python library, for example

export PYTHONPATH=/usr/lib/python2.7

If this is not set up correctly, references to library code will not be found.


If you hope to contribute to PySonar2, please contact me first before making big changes.

For development, you can run the unit tests. PySonar2 has a test framework. You can run the tests using this command:

mvn test

If you modify the code or tests, you need to generate new expected results. Run these command lines:

mvn package -DskipTests
java -classpath target/pysonar-<version>.jar org.yinwang.pysonar.TestInference -generate tests

To write new tests, you just need to write relevant Python files, put them into a directory named tests/testname.test(test directory name must end with ".test"). Please look at the tests directory for examples.


Apache 2.0 License. See LICENSE file.

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