wxPython

wxPython is a wrapper for the cross-platform GUI API (often referred to as a "toolkit") wxWidgets (which is written in C++) for the Python programming language.

In 1995, Robin Dunn needed a GUI application to be deployed on HP-UX systems but also run Windows 3.1 within short time frame.

While evaluating free and commercial solutions, he ran across Python bindings on the wxWidgets toolkit webpage (known as wxWindows at the time).

[2] In 2010, the Project Phoenix began; an effort to clean up the wxPython implementation and in the process make it compatible with Python 3.

[7] wxPython enables Python to be used for cross-platform GUI applications requiring very little, if any, platform-specific code.

Close button with wxPython shown on Windows 10