How to add or increment a dictionary entry?

Question

I\'m currently re-engaging with Python after a long absence and loving it. However, I find myself coming across a pattern over and over. I keep thinking that there must be a

Answer 1

Use a defaultdict:

from collections import defaultdict

foo = defaultdict(int)
foo[bar] += 1

In Python >= 2.7, you also have a separate Counter class for these purposes. For Python 2.5 and 2.6, you can use its backported version.