Calculate difference in keys contained in two Python dictionaries

Question

Suppose I have two Python dictionaries - dictA and dictB. I need to find out if there are any keys which are present in dictB but not

Answer 1

If you really mean exactly what you say (that you only need to find out IF "there are any keys" in B and not in A, not WHICH ONES might those be if any), the fastest way should be:

if any(True for k in dictB if k not in dictA): ...

If you actually need to find out WHICH KEYS, if any, are in B and not in A, and not just "IF" there are such keys, then existing answers are quite appropriate (but I do suggest more precision in future questions if that's indeed what you mean;-).