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pythonpython-3.xcounter

Sum of all counts in a collections.Counter

What is the best way of establishing the sum of all counts in a collections.Counter object?

I've tried:

sum(Counter([1,2,3,4,5,1,2,1,6]))

but this gives 21 instead of 9?

Solution

  • The code you have adds up the keys (i.e. the unique values in the list: 1+2+3+4+5+6=21).

    To add up the counts, use:

    In [4]: sum(Counter([1,2,3,4,5,1,2,1,6]).values())
Out[4]: 9

    This idiom is mentioned in the documentation, under "Common patterns".