Am 10.10.21 um 10:49 schrieb Steve Keller:
I have found the sum() function to be much slower than to loop over the
operands myself:
def sum_products(seq1, seq2):
return sum([a * b for a, b in zip(seq1, seq2)])
def sum_products2(seq1, seq2):
sum = 0
for a, b in zip(seq1, seq2):
sum += a * b
return sum
In a program I generate about 14 million pairs of sequences of ints each
of length 15 which need to be summed. The first version with sum() needs
44 seconds while the second version runs in 37 seconds.
The first version constructs a list, sums it up and throws the list
away, while the second version only keeps the running sum in memory. How
about a generator expression instead, i.e.
sum((a * b for a, b in zip(seq1, seq2)))
(untested) ?
Christian
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