def find_plugins():
    load_plugins()
    plugins = []
    for cls in _classes:
        # Only instantiate each plugin class once.
        if cls not in _instances:
            _instances[cls] = cls()
        plugins.append(_instances[cls])
    return plugins


# Communication with plugins.
Add parse action to expression's list of parse actions. See L{I{setParseAction}<setParseAction>}.
dataset/ETHPy150Open beetbox/beets/beets/plugins.py/find_plugins--crossover with--dataset/ETHPy150Open pypa/pip/pip/_vendor/pyparsing.py/ParserElement.addParseAction