python拆分空字符串 [英] python split empty string

问题描述

有人可以在 python 2.7.8 上解释这种行为吗:

Could someone explain this behaviour on python 2.7.8:

Python 2.7.8 (default, Nov 12 2014, 02:03:09)
[GCC 4.8.2 20140120 (Red Hat 4.8.2-16)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> a = ''
>>> a.split()
[]
>>> a.split('\n')
['']

被任何空格分割会得到一个空列表，但被新行分割会得到一个带有空字符串的列表.为什么?

split by any white space gives an empty list, but split by new line gives a list with an empty string. WHY?

谢谢

推荐答案

基于 python 维基 :

str.split([sep[, maxsplit]])

如果给出了 sep，则连续的分隔符不会组合在一起并被视为分隔空字符串(例如，'1,,2'.split(',') 返回 ['1', '', '2']).sep 参数可能由多个字符组成(例如，'1<>2<>3'.split('<>') 返回 ['1', '2', '3']).用指定的分隔符拆分空字符串返回 [''].

If sep is given, consecutive delimiters are not grouped together and are deemed to delimit empty strings (for example, '1,,2'.split(',') returns ['1', '', '2']). The sep argument may consist of multiple characters (for example, '1<>2<>3'.split('<>') returns ['1', '2', '3']). Splitting an empty string with a specified separator returns [''].

如果 sep 未指定或为 None，则应用不同的拆分算法:将连续空白的运行视为单个分隔符，结果将不包含如果字符串有前导或尾随空格，则在开头或结尾处为空字符串.因此，用 None 分隔符分割空字符串或仅由空格组成的字符串将返回 [].

If sep is not specified or is None, a different splitting algorithm is applied: runs of consecutive whitespace are regarded as a single separator, and the result will contain no empty strings at the start or end if the string has leading or trailing whitespace. Consequently, splitting an empty string or a string consisting of just whitespace with a None separator returns [].

有关更多解释，请阅读此答案https://stackoverflow.com/a/16645307/2867928

For more explanation read this answer too https://stackoverflow.com/a/16645307/2867928

这篇关于python拆分空字符串的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！