def deserialize_usage_key(usage_key_string, course_key):
 return UsageKey.from_string(usage_key_string).replace(course_key=course_key)

def deserialize_usage_key ( usage_key_string , course_key ) : return UsageKey . from_string ( usage_key_string ) . replace ( course_key = course_key )
returns the deserialized usagekey object of the given usage_key_string for the given course .