PySide6 vs. pyqt: Finding Qt Plugins

__main__.py

import os
from pathlib import Path
import sys
import sysconfig
from PySide6.QtCore import QCoreApplication
from PySide6.QtWidgets import QApplication
from .main_win import MainWin


def main() -> int:
    # If you're trying to install a wheel that depends on PySide6
    # in a conda environment that already has conda's pyqt, the
    # wheel's code may crash when instantiating QApplication:
    #   Found invalid metadata in lib \
    #     /path/to/conda/env/plugins/platforms/libqcocoa.dylib: \
    #     Invalid metadata version
    #
    # A workaround: before instantiating QApplication, set QT_PLUGIN_PATH
    # to point to the PySide6 package in the currently running Python:

    site_pkgs = Path(sysconfig.get_path("platlib"))
    ps6_qt_plugins = site_pkgs / "PySide6" / "Qt" / "plugins"
    if ps6_qt_plugins.is_dir() and ("QT_PLUGIN_PATH" not in os.environ):
        os.environ["QT_PLUGIN_PATH"] = os.fspath(ps6_qt_plugins)

    app = QApplication(sys.argv)
    mainWin = MainWin()
    mainWin.show()
    return app.exec()


if __name__ == "__main__":
    main()