Python: Why is functools.partial necessary?

Partial application is cool. What functionality does functools.partial offer that you can’t get through lambdas?

>>> sum = lambda x, y : x + y
>>> sum(1, 2)
3
>>> incr = lambda y : sum(1, y)
>>> incr(2)
3
>>> def sum2(x, y):
    return x + y

>>> incr2 = functools.partial(sum2, 1)
>>> incr2(4)
5

Is functools somehow more efficient, or readable?

6 Answers
6

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