Modern Python Standard Library Cookbook

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Relying on Counter is actually not the only way to track frequencies; we already know that Counter is a special kind of dictionary, so reproducing the Counter behavior should be quite straightforward.

Probably every one of us came up with a dictionary in this form:

counts = dict(hello=0, world=0, nice=0, day=0)

Whenever we face a new occurrence of hello, world, nice, or day, we increment the associated value in the dictionary and call it a day:

for word in 'hello world this is a very nice day'.split():
    if word in counts:
        counts[word] += 1

By relying on dict.get, we can also easily adapt it to count any word, not just those we could foresee:

for word in 'hello world this is a very nice day'.split(): counts[word] = counts.get(word, ...