python 字符串剥离奇怪的行为

Question

这个问题已经有答案了:

How do the .strip/.rstrip/.lstrip string methods work in Python? (4 个回答)

已关闭 4 年前。

我出现这种字符串剥离行为是否有原因？这是一个错误还是我缺少一些字符串魔法

# THIS IS CORRECT
>>> 'name.py'.rstrip('.py')
'name'


# THIS IS WRONG     
>>> 'namey.py'.rstrip('.py')
'name'

# TO FIX THE ABOVE I DID THE FOLLOWING
>>> 'namey.py'.rstrip('py').rstrip('.')
'namey'

Answer 1

这是因为 str.rstrip() 命令删除每个尾随字符，而不是整个字符串。

https://docs.python.org/2/library/string.html

string.rstrip(s[, chars]) Return a copy of the string with trailing characters removed. If chars is omitted or None, whitespace characters are removed. If given and not None, chars must be a string; the characters in the string will be stripped from the end of the string this method is called on.

This also generates same result
>>> 'nameyp.py'.rstrip('.py')
'name'

你可以尝试str().endswith

>>> name = 'namey.py'
... if name.endswith('.py'):
...     name = name[:-3]

>>> name
'namey'

或者只是str().split()

>>> 'namey.py'.split('.py')[0]
'namey'