Python - strip - lstrip - rstrip

忘是亡心i 2023-02-16 01:56 7阅读 0赞

# **Python - strip - lstrip - rstrip** #

**Built-in Types - 内置类型**  
[https://docs.python.org/3/library/stdtypes.html][https_docs.python.org_3_library_stdtypes.html]  
[https://docs.python.org/zh-cn/3/library/stdtypes.html][https_docs.python.org_zh-cn_3_library_stdtypes.html]

## 1. `str.strip([chars])` ##

Return a copy of the string with the leading and trailing characters removed. The chars argument is a string specifying the set of characters to be removed. If omitted or `None`, the chars argument defaults to removing whitespace. The chars argument is not a prefix or suffix; rather, all combinations of its values are stripped:  
返回原字符串的副本，移除其中的前导和末尾字符。chars 参数为指定要移除字符的字符串。如果省略或为 None，则 chars 参数默认移除空格符。**实际上 chars 参数并非指定单个前缀或后缀，而是会移除参数值的所有组合。前导和末尾的单个前缀或后缀依次取出对比，只要在 chars 参数里面，就移除。**

>>> '   spacious   '.strip()
    'spacious'
    >>> 'www.example.com'.strip('cmowz.')
    'example'

The outermost leading and trailing chars argument values are stripped from the string. Characters are removed from the leading end until reaching a string character that is not contained in the set of characters in chars. A similar action takes place on the trailing end. For example:  
最外侧的前导和末尾 chars 参数值将从字符串中移除。开头端的字符的移除将在遇到一个未包含于 chars 所指定字符集的字符时停止。类似的操作也将在结尾端发生。

>>> comment_string = '#....... Section 3.2.1 Issue #32 .......'
    >>> comment_string.strip('.#! ')
    'Section 3.2.1 Issue #32'

## 2. `str.lstrip([chars])` ##

Return a copy of the string with leading characters removed. The chars argument is a string specifying the set of characters to be removed. If omitted or `None`, the chars argument defaults to removing whitespace. The chars argument is not a prefix; rather, all combinations of its values are stripped:  
返回原字符串的副本，移除其中的前导字符。chars 参数为指定要移除字符的字符串。如果省略或为 `None`，则 chars 参数默认移除空格符。**实际上 chars 参数并非指定单个前缀或后缀，而是会移除参数值的所有组合。前导和末尾的单个前缀或后缀依次取出对比，只要在 chars 参数里面，就移除。**

>>> '   spacious   '.lstrip()
    'spacious   '
    >>> 'www.example.com'.lstrip('cmowz.')
    'example.com'

## 3. `str.rstrip([chars])` ##

Return a copy of the string with trailing characters removed. The chars argument is a string specifying the set of characters to be removed. If omitted or `None`, the chars argument defaults to removing whitespace. The chars argument is not a suffix; rather, all combinations of its values are stripped:  
返回原字符串的副本，移除其中的末尾字符。chars 参数为指定要移除字符的字符串。如果省略或为 None，则 chars 参数默认移除空格符。**实际上 chars 参数并非指定单个前缀或后缀，而是会移除参数值的所有组合。前导和末尾的单个前缀或后缀依次取出对比，只要在 chars 参数里面，就移除。**

>>> '   spacious   '.rstrip()
    '   spacious'
    >>> 'mississippi'.rstrip('ipz')
    'mississ'

## 4. example ##

(base) yongqiang@yongqiang:~$ python
    Python 3.7.6 (default, Jan  8 2020, 19:59:22)
    [GCC 7.3.0] :: Anaconda, Inc. on linux
    Type "help", "copyright", "credits" or "license" for more information.
    >>> str = "0000000this is string example....wow!!!0000000"
    >>> str.strip('0')
    'this is string example....wow!!!'
    >>> exit()
    (base) yongqiang@yongqiang:~$
    (base) yongqiang@yongqiang:~$ python
    Python 3.7.6 (default, Jan  8 2020, 19:59:22)
    [GCC 7.3.0] :: Anaconda, Inc. on linux
    Type "help", "copyright", "credits" or "license" for more information.
    >>> str = "\t\n\rqiang\n\r\t"
    >>> str.strip()
    'qiang'
    >>>
    >>> str = "2112cheng12yong12qiang1221"
    >>> str.strip("12")
    'cheng12yong12qiang'
    >>>
    >>> str = "2112cheng12yong12qiang1221"
    >>> str.strip("21")
    'cheng12yong12qiang'
    >>>
    >>> str = "2122212cheng12yong12qiang1211121"
    >>> str.strip("21")
    'cheng12yong12qiang'
    >>> exit()
    (base) yongqiang@yongqiang:~$

[https_docs.python.org_3_library_stdtypes.html]: https://docs.python.org/3/library/stdtypes.html
[https_docs.python.org_zh-cn_3_library_stdtypes.html]: https://docs.python.org/zh-cn/3/library/stdtypes.html