def METHOD_NAME() -> Iterable[Path]:
    """Iterates over all Python source files that are part of Quod Libet"""
    import quodlibet
    root = Path(get_module_dir(quodlibet)).parent
    skip = [root / d for d in
            ("build",
             "dist",
             "docs",
             "dev-utils",
             Path("quodlibet") / "packages")
            ]
    # Path.glob() not efficient on big trees :(
    for dirpath, dirnames, filenames in os.walk(root):
        root = Path(dirpath)
        parents = root.parents
        if root.name.startswith(".") or any(s in parents for s in skip):
            # Don't test *any* subdirs of hidden / ignored parents
            dirnames.clear()
            continue
        for filename in filenames:
            if filename.endswith('.py'):
                yield root / filename