input().strip().split() 和 input().split() 有什么区别？

Question

Split() function uses whitespace string as separator and removes the empty strings, so I think there is no use using strip() or rstrip() function to remove extra whitespace in head or tail. And here is my example:

a = ' \n   1 2 3 4     \n\n 5 \n\n \t'
b = a.rstrip().split()
c = a.split()
print('b =',b)
print('c =',c)

The result turns out to be:

b = ['1', '2', '3', '4', '5']
c = ['1', '2', '3', '4', '5']

It seems that there is no difference in betweeen. However, the former one( intput().strip().split()) seems more widely used. So what is the difference in these two expressions?

Answer 1

There's no difference. split() ignores whitespace on the ends of the input by default. People call strip() first either because they think it's clearer or because they don't know this behavior of split().

Docs:

如果 sep 未指定或为 None，则应用不同的分割算法：连续的空格被视为单个分隔符，如果字符串具有前导或尾随空格，则结果将在开头或结尾不包含空字符串。因此，使用 None 分隔符分割空字符串或仅包含空格的字符串将返回 []。