A.deepcopy() returns a deep copy of athing. That means, that if athing is a nested data structure such as a list, dict or tuple, its elements will be deep copied as well.
dict(K.deepcopy(V) adict, int level) returns a deep copy of adict. level specifies the level up to which elements are copied. a.deepcopy(0) does not copy a, but returns a itself. If level is negative, the deep copy level is unlimited.