python - python在文本文件中搜索字符串并将值添加到变量

Question

我有一个这样的文本文件

PC Name : Sarah , IP : x.x.x.x
ID : AC:AC LP
PC Name : Moh, IP : x.x.x.x
ID : AC:AC LP

我想从文件末尾向上搜索以找到字符串“ AC：AC LP”的第一个匹配项
然后我要复制上一行中的ip并将其添加到名为ip的新变量中

我搜索了代码，但它们都使用常规搜索并复制了相同的字符串，请您帮忙

Answer 1

with open(in_file) as f:
     lines = reversed(f.readlines()) # start from end of file
     for line in lines:
         if "AC:AC LP" in line: # if AC:AC LP is in the line 
             print( next(lines).rsplit(":",1)[-1]) # go to  next line, split, get ip and break the loop
             break

在函数中：

def find_ip(in_file,sub_s):
    with open(in_file) as f:
        lines = reversed(f.readlines())
        for line in lines:
            if sub_s in line:
                return next(lines).rsplit(":", 1)[-1]

如果ip并不总是最后一个元素，请使用re：

def find_ip(in_file,sub_s):
    import re
    with open(in_file) as f:
        lines = reversed(f.readlines())
        for line in lines:
            if sub_s in line:
                return re.findall(r"[0-9]+(?:\.[0-9]+){3}",next(lines))[0]