正则表达式python字符串忽略特殊字符

Question

This is what i have now :

import re

x = "From: Joyce IP: 192.111.1.1 Source: 192.168.1.1"    
x = x.replace(' ', '')
m = re.findall('(?<=:)\S+', x)
print m 

And I want to have a output like this to make this $ script.py > result.txt :

Joyce 192.111.1.1 192.168.1.1

Answer 1

Instead of finding the matches of the text you want as the result, it may be easier to replace the stuff you don't want:

>>> import re
>>> x = "From: Joyce IP: 192.111.1.1 Source: 192.168.1.1"
>>> re.sub(r'\w+:\s', '', x)
'Joyce 192.111.1.1 192.168.1.1'

However, if you prefer to use re.findall() here is one option that is similar to your current approach:

>>> ' '.join(re.findall(r'(?<=:\s)\S+', x))
'Joyce 192.111.1.1 192.168.1.1'

You need the \\s in the negative lookbehind because there is a space after each of the colons in your input string.

Answer 2

a slight change to your code (don't remove the spaces, and include them in the look behind) works perfectly:

import re

x = "From: Joyce IP: 192.111.1.1 Source: 192.168.1.1"    
m = re.findall('(?<=:\s)\S+', x)
print " ".join(m) 

Answer 3

import re

x = "From: Joyce IP: 192.111.1.1 Source: 192.168.1.1"    

reg = r"\d{1,3}(?:[.]\d+){3}"

m = re.findall(reg, x)

for i in m:
  print(i)

Result : 192.111.1.1 192.168.1.1