Probably expecting something like you get from collections.defaultdict: "dict subclass that calls a factory function to supply missing values": https://docs.pyt

Probably expecting something like you get from collections.defaultdict: "dict subclass that calls a factory function to supply missing values": https://docs.python.org/2/library/collections.html#collections.defaultdict https://docs.python.org/2/library/collections.html#collectio...