https://zhuanlan.zhihu.com/p/114371624

正则表达式-python：split的用法

在python种split的作用：修改字符串（Modifying a string）
In almost every language, you can find the split operation in strings.
在python3中使用split特别注意两点：

  • 正则表达式（pattern）带不带括号的区别

  • 第一个字符就与正则表达式匹配，结果中的第一个位置会包含一个空字符（Note that when a group matches the start of the string, the result will contain the empty string as a first result.）

    正则表达式（pattern）带不带括号的区别

    image.png

    第一个字符就与正则表达式匹配

    image.png

    参数maxsplit的用法：

    image.png

    需要多个分隔符时用中括号[]

    image.png
    最后附上所有源码：

    Modifying a string

  • In almost every language, you can find the split operation in strings.

import re

  • Note that when a group matches the start of the string, the result will contain the empty string as a first result:

re.split(r”\n”, “Beautiful is better than ugly.\nExplicit is better than implicit.”) [‘Beautiful is better than ugly.’, ‘Explicit is better than implicit.’] re.split(r”(\n)”, “Beautiful is better than ugly.\nExplicit is better than implicit.”) [‘Beautiful is better than ugly.’, ‘\n’, ‘Explicit is better than implicit.’] pattern = re.compile(r”(-)”) #注意此处的括号，与groups有关 pattern.split(“-hello-word”) [‘’, ‘-‘, ‘hello’, ‘-‘, ‘word’] pattern = re.compile(r”(-)”) #注意此处的括号，与groups有关 pattern.split(“hello-word”) [‘hello’, ‘-‘, ‘word’] pattern = re.compile(r”\W”) pattern.split(“Beautiful is better than ugly”, 2) #The maxsplit parameter specifies how many splits can be done at maximum [‘Beautiful’, ‘is’, ‘better than ugly’] pattern = re.compile(r”\W”) pattern.split(“Beautiful is better than ugly”) #The maxsplit parameter specifies how many splits can be done at maximum [‘Beautiful’, ‘is’, ‘better’, ‘than’, ‘ugly’] pattern = re.compile(r”(\W)”) pattern.split(“⇢hello⇢word”) [‘’, ‘⇢’, ‘hello’, ‘⇢’, ‘word’] pattern = re.compile(r”([\W,l])”) pattern.split(“⇢hello⇢word”) [‘’, ‘⇢’, ‘he’, ‘l’, ‘’, ‘l’, ‘o’, ‘⇢’, ‘word’]
发布于 2020-03-19 14:28