def set_key(self, key, value, namespace=None, expire=<NUM_LIT:0>):
with (yield from self._pool) as redis:<EOL><INDENT>if namespace is not None:<EOL><INDENT>key = self._get_key(namespace, key)<EOL><DEDENT>yield from redis.set(key, value, expire=expire)<EOL><DEDENT>
Set a key in a cache.
:param key: Key name
:param value: Value
:param namespace : Namespace to associate the key with
:param expire: expiration
:return: