import types

class Plugin(object):
    pass

def getPlugins(subclassof=Plugin):
    import sys, os
    dirname = os.path.join(sys.path[0], *__path__)
    files = os.listdir(dirname)
    modules = filter(lambda f: f.split('.')[-1] in ('py', 'pyc') and not f.startswith('__'), files)
    modulenames = set(['.'.join(filename.split('.')[:-1]) for filename in modules])
    ret = []
    for modulename in modulenames:
        module = __import__(modulename, globals(), locals(), ['plugins'])
        for obj in [getattr(module, x) for x in dir(module)]:
            if type(obj) == type and issubclass(obj, subclassof):
                ret.append(obj)
    return ret