正则表达式不正确的输出由python。

import os,re
def test():
    list  = re.findall(r'(255\.){2}','255.255.252.255.255.12')
    print list
if __name__ == '__main__':
test()

the output ：“['255.', '255.']”

输出:“(255年。”、“255年。””

why not 【255.255，255.255】？

为什么不【255.255,255.255】呢?

the mactch object should is "255.255"

mactch对象应该是“255.255”

How can i get the correct output result?

如何得到正确的输出结果?

2 个解决方案

#1

Mm, not quite. First off, you'll want a non-capturing group - the capturing group you have there will only capture '255.', and use that as the output for re.findall.

嗯,不完全是。首先，您需要一个非捕获组——您拥有的捕获组将只捕获'255。，并将其用作re.findall的输出。

Example:

例子:

re.findall(r'(?:255\.){2}', '255.255.252.255.255.12')

The (?:) construct is a non-capturing group - and without any capturing groups, re.findall returns the entire matching string.

构造(?:)是一个非捕获组——没有任何捕获组，re.findall返回整个匹配的字符串。

Note that this won't actually return ['255.255', '255.255'] - it will actually return ['255.255.', '255.255.'].

注意，它实际上不会返回['255.255'，'255.255']-它实际上会返回['255.255']。”、“255.255。”)。

#2

In your regex, you're only capturing the first 255.. You need to wrap everything you want to capture in a capturing group:

在您的regex中，您只捕获了前255..你需要把你想要捕捉的每一件东西都包裹起来:

>>> re.findall(r'((?:255\.){2})','255.255.252.255.255.12')
['255.255.', '255.255.']

(?:...) is a non-capturing group. It basically lets you group things without having them show up as a captured group.

是一个不抓人的群体。它基本上允许你对事物进行分组，而不让它们作为一个捕获的组显示出来。

#1