The PyInstaller project follows the PEP 8 Style Guide for Python Code for new code.
Please check your code with a style guide checker, e.g. flake8.
Please abstain from reformatting existing code, even it it doesn’t follow PEP 8. We will not accept reformatting changes since they make it harder to review the changes and to follow changes in the long run. For a complete rational please see #2727.