cache.py 文件源码

def import_preferred_memcache_lib(self, servers):
        """Returns an initialized memcache client.  Used by the constructor."""
        try:
            import pylibmc
        except ImportError:
            pass
        else:
            return pylibmc.Client(servers)

        try:
            from google.appengine.api import memcache
        except ImportError:
            pass
        else:
            return memcache.Client()

        try:
            import memcache
        except ImportError:
            pass
        else:
            return memcache.Client(servers)


# backwards compatibility