python-打印包含正则表达式匹配项的行和列表

Question

我有一个日志文件，至少有一千行

abc.txt:
1. example eg, ham, cheese 350.122.345.8
2. cheese ham eg, example 231.242.1.2
3. Ham cheese, example,e.g 100.200.100.200
4.
5. Ham cheese, example,e.g 100.200.100.200
1000. 

我想要的最终结果：

仅打印与ip地址范围内的数字匹配的那些行。 因此，它应该仅打印：

2. cheese ham eg, example 231.242.1.2
3. Ham cheese, example,e.g 100.200.100.200
5. Ham cheese, example,e.g 100.200.100.200

我尝试了以下代码，但无法获得所需的结果：

import re

txt=open('/sdcard/Download/abc.txt','r')

pattern=re.compile('(^[2][0-5][0-5]|^[1]{0,1}[0-9]{1,2})\.([0-2][0-5][0-5]|[1]{0,1}[0-9]{1,2})\.([0-2][0-5][0-5]|[1]{0,1}[0-9]{1,2})\.([0-2][0-5][0-5]|[1]{0,1}[0-9]{1,2})$', re.DOTALL)

for line in txt:
    if str(pattern) in line:
        print line
    else:
        print 'WRONG LINE:',line

返回的结果是打印出的完整行列表，并显示我的else WRONG LINE消息。

我用在线检查器检查了我的正则表达式，它显示正确的行为，匹配不超过.255的所有ipv4地址

请指出我的错误。

Answer 1

这是更正后的正则表达式和代码：

import re

txt= {"1. example eg, ham, cheese 350.122.345.8",
      "2. cheese ham eg, example 231.242.1.2",
      "3. Ham cheese, example,e.g 100.200.100.200",
      "4.",
      "5. Ham cheese, example,e.g 100.200.100.200"}


pattern=re.compile('([2][0-5][0-5]|[1]{0,1}[0-9]{1,2})\.([0-2][0-5][0-5]|[1]{0,1}[0-9]{1,2})\.([0-2][0-5][0-5]|[1]{0,1}[0-9]{1,2})\.([0-2][0-5][0-5]|[1]{0,1}[0-9]{1,2})', re.DOTALL)

for line in txt:
    if pattern.search(line):
        print line
    else:
        print 'WRONG LINE:',line

Answer 2

来自：@RudyTheHunter

import re

txt=open('/sdcard/Download/abc.txt','r')

pattern=re.compile('([2][0-5][0-5]|[1]{0,1}[0-9]{1,2})\.([0-2][0-5][0-5]|[1]{0,1}[0-9]{1,2})\.([0-2][0-5][0-5]|[1]{0,1}[0-9]{1,2})\.([0-2][0-5][0-5]|[1]{0,1}[0-9]{1,2})', re.DOTALL)

for line in txt:
    if pattern.search(line):
        print line
    else: 
        print 'WRONG LINE:',line