Python在列表列表中查找值 [英] Python finding a value in a list of lists

问题描述

最近，我不得不找到某物在哪个列表中.我曾经使用过:

Recently I had to find which list something was in. I used:

def findPoint(haystack, needle): # haystack = [[1,2,3], [4,5]...,[6,7,8,9]]
    for x in range(len(haystack)):
        if needle in haystack[x]:
            return x
    raise Exception("needle: " + str(needle) + " not in haystack")

有一个haystack.index(needle)方法. 问题是:是否有更好的方法来做到这一点?"

There is a haystack.index(needle) method. The question is: "Is there a better way to do this?"

推荐答案

是的，对于初学者来说，不需要范围

Yes, no need for range, for starters

for hay in haystack:
  if needle in hay:
    return hay

如果您确实需要索引，请使用enumerate

And if you really really need the index, use enumerate

for x, hay in enumerate(haystack):
  if needle in hay:
    return x

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