改变案例以降低[关闭]

Question

我是 python 新手，正在尝试将许多字符串的大小写更改为小写。

许多字符串作为列表的元素包含，列表本身是字典的键（字符串数据类型）的值。

这是字典：

{
'1000268201_693b08cb0e'  :  ['A child in a pink dress is climbing up a set  of stairs in an entry way .', 'A girl going into a wooden building .', 'A little girl climbing into a wooden playhouse .', 'A little girl climbing the stairs to her playhouse .', 'A little girl in a pink dress going into a wooden cabin .'],
'101654506_8eb26cfb60'   :  ['A brown and white dog is running through the snow .', 'A dog is running in the snow', 'A dog running through snow .', 'a white and brown dog is running through a snow covered field .', 'The white and brown dog is running over the surface of the snow .']
}

我为上述字典编写的代码，键为1000268201_693b08cb0e 和101654506_8eb26cfb60，作为句子列表的值是：

for i in mapping:
    for j in range(0,len(mapping[i])):
        mapping[i][j]=mapping[i][j].lower();

什么是完成上述工作的有效而简洁的方法？

Answer 1

你可以再简化一点：

my_dict = {'some_key': ['A', 'B', 'C'], 'another_key': ['D', 'E', 'F']}

for key in my_dict:
    my_dict[key] = [x.lower() for x in my_dict[key]]

这样您就不必致电len()。