查找列表中项目的平均长度.蟒蛇

Question

my_list = [['abcdefg','awdawdawd'],['awdwer'],[],'rtgerfwed','wederfrtg']]

所以我有一个列表,我想找到列表中每个子列表的平均长度

我试过这个,但它似乎没有用

lengths = []
lengths = my_list

for k in lengths:
    k = len(k)

print lengths

# i get this again -> [['abcdefg','awdawdawd'],['awdwer'],[],'rtgerfwed','wederfrtg']]

我希望输出

lengths = [8,6,0,9]

Answer 1

列表中每个元素的长度列表:

lengths = [len(i) for i in my_list]

对于平均值:

def averageLen(lst):
    lengths = [len(i) for i in lst]
    return 0 if len(lengths) == 0 else (float(sum(lengths)) / len(lengths)) 

如果是列表清单:

lengths = [averageLen(i) for i in my_list]