How does defaultdict work?

1.  defaultdict will automatically create a dictionary for you that has keys which are the integers 0-10.
2.  defaultdict forces a dictionary to only accept keys that are of the data type specified when you created the defaultdict (such as strings or integers).
3.  If you try to read from a defaultdict with a nonexistent key, a new default key-value pair will be created for you instead of throwing a KeyError.
4.  defaultdict stores a copy of a dictionary in memory that you can default to if the original gets unintentionally modified.

Correct Answer:

•  If you try to read from a defaultdict with a nonexistent key, a new default key-value pair will be created for you instead of throwing a KeyError.