Python’s collections module has some of the most consistently useful collection data structures you will need for everyday programming. Here’s one I didn’t know about, collections.Counter (Python 2.7 only!). It is designed to keep “tallies” or count instances of something. The example will make it all clear:
from collections import Counter
cars = Counter()
# I see one go past, it is red
cars['red'] += 1
# And a green one
cars['blue'] += 1
# etcThis is pretty much like a defaultdict with an integer value, but it is convenient and neat, with a useful constructor.
There’s more. “Are two strings anagrams?”
are_anagrams = lambda s1, s2: Counter(s1) == Counter(s2)Replied the smartass.
