For循环正在跳过一些内容！ Python [英] For loop is skipping some stuff! Python

问题描述

我正在尝试运行此代码，以便它为列表的所有元素运行一个函数.出于说明目的，基本上应该打印:

I'm trying to run this code so that it runs a function for all elements of a list. For illustrative purposes here, basically it should print:

'----------Possible Word:', possible_word

我列表中的所有项目.因此，如果我要输入['p'，'r'，'s']，它将打印3次，其中每个项目一次.我的代码在下面-当我运行它时，它只运行p和s，而不运行r，这确实很奇怪.有什么想法吗?

for all items in my list. So, if I were to input ['p', 'r', 's'] it would run that print 3 times, one for each of those items. My code is below - when I run it it only runs for p and s, not r, which is really odd. Any ideas?

def check_matches(input):
print 'Input:', input
for possible_word in input:
    print '----------Possible Word:', possible_word
    valid = True
    for real_word in word_dictionary:
        possible_word_list = list(possible_word)
        real_word_list = list(real_word)
        print possible_word_list
        print real_word_list
        number_of_characters_to_check = len(possible_word_list)
        for x in range(0, number_of_characters_to_check):
            print possible_word_list[x] + real_word_list[x]
            if (possible_word_list[x] != real_word_list[x]):
                valid = False
    if (valid == False):
        input.remove(possible_word)
print all_possible
return input

推荐答案

运行input.remove(possible_word)时，您正在更改恰好要遍历的列表的大小，这将导致特殊的结果.通常，请勿更改要迭代的任何内容.

When you run input.remove(possible_word) you're changing the size of the list which you happen to be iterating over, which leads to peculiar results. In general, don't mutate anything that you're iterating over.

更简洁的示例:

>>> lst = ['a', 'b', 'c']
>>> for el in lst:
    print el
    lst.remove(el)

a
c

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