计算列表列表中有空白列表的次数 [英] Counting how many times there are blank lists in a list of list

问题描述

我有一个列表:

l = [['a', []], ['b', []], ['c', []], ['d', ['e']], ['f', []], ['g', ['h']], ['i', ['j']]]

我想计算多少个列表的第一个元素旁边有元素[]. 例如，在此列表中，我们有4个列表，其第一个元素旁边有一个空白列表.

I want to count how many lists have the element [] next to the first element. for example, in this list we have 4 lists that have a blank list next to its first element.

另一个例子可能是:

l2 = [['a', []], ['b', []], ['c', []], ['d', ['e', 'f']], ['g', ['h', 'i']], ['j', ['k', 'l']], ['m', ['n', 'o']]]

在这里，我们有3个列表，这些列表的元素在列表的第一个元素旁边[

Here we have 3 lists that have elements that are [] next to the first element of a list.

I tried doing something like, but it returns 0
`````````````
def counting(l):
    c = sum(x.count("[]")for x in L)
    return c

推荐答案

这是一个单行解决方案，可以满足您的需求

Here is a single line solution doing what you want

def counting(l):
    return sum(x.count([]) for x in l)

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