看这一行:

sublist = sublist.insert(len(sublist), i+1)

insert None ,所以在下面的迭代中

the_list.extend(sublist)

sublist 是 虽然 extend 函数需要iterable参数。固定代码:

def make_list_of_lists(n):
    the_list = []
    sublist = []
    for i in range(n):
        print(sublist)
        the_list.extend(sublist)
        sublist.insert(len(sublist), i + 1)
    return the_list

make_list_of_lists(3)

[一]

[1,2]

python2和python3中都没有这样的函数,因此必须自己添加代码:

def decapitalize(s):
    if not s:  # check that s is not empty string
        return s
    return s[0].lower() + s[1:]