def load_hashers(password_hashers=None):
    global HASHERS
    global PREFERRED_HASHER
    hashers = []
    if not password_hashers:
        password_hashers = settings.PASSWORD_HASHERS
    for backend in password_hashers:
        try:
            mod_path, cls_name = backend.rsplit('.', 1)
            mod = importlib.import_module(mod_path)
            hasher_cls = getattr(mod, cls_name)
        except (AttributeError, __HOLE__, ValueError):
            raise ImproperlyConfigured("hasher not found: %s" % backend)
        hasher = hasher_cls()
        if not getattr(hasher, 'algorithm'):
            raise ImproperlyConfigured("hasher doesn't specify an "
                                       "algorithm name: %s" % backend)
        hashers.append(hasher)
    HASHERS = dict([(hasher.algorithm, hasher) for hasher in hashers])
    PREFERRED_HASHER = hashers[0]
dataset/ETHPy150Open AppScale/appscale/AppServer/lib/django-1.4/django/contrib/auth/hashers.py/load_hashers