将元组的迭代转换为每个元素的迭代（Python）

Question

I have an iterable delta that generates tuple of two numbers (dx, dy) , and I want to compute the sum of each. The following doesn't work since delta is disposed after the first iteration.

x = sum(dx for dx, dy in delta)
y = sum(dy for dx, dy in delta)

Any idea? I'm thinking in the direction of somehow turning delta into two iterables of dx and dy , but have reached nothing so far.

Answer 1

使用zip()和map()函数在每列上应用sum() ：

x, y = map(sum, zip(*delta))

Answer 2

This ought to do it!

ysum = 0
xsum = 0

for dx, dy in delta:
    xsum += dx
    ysum += dy

The idea with a generator is that you can exhaust it once, so why not just do all of your math in one go?