条件中的python正则表达式匹配 [英] Python regex matching in conditionals

问题描述

我正在解析文件，我想针对一些复杂的正则表达式检查每一行.像这样

I am parsing file and I want to check each line against a few complicated regexs. Something like this

if re.match(regex1, line): do stuff
elif re.match(regex2, line): do other stuff
elif re.match(regex3, line): do still more stuff
...

当然，要做这些事情，我需要匹配对象.我只能想到三种可能性，每种可能性都有待改进.

Of course, to do the stuff, I need the match objects. I can only think of three possibilities, each of which leaves something to be desired.

if re.match(regex1, line): 
    m = re.match(regex1, line)
    do stuff
elif re.match(regex2, line):
    m = re.match(regex2, line)
    do other stuff
...

这需要进行两次复杂的匹配(这些都是长文件和长正则表达式:/)

which requires doing the complicated matching twice (these are long files and long regex :/)

m = re.match(regex1, line)
if m: do stuff
else:
    m = re.match(regex2, line)
    if m: do other stuff
    else:
       ...

随着我越来越缩进，这变得很糟糕.

which gets terrible as I indent further and further.

while True:
    m = re.match(regex1, line)
    if m:
        do stuff
        break
    m = re.match(regex2, line)
    if m:
        do other stuff
        break
    ...

看起来很奇怪.

什么是正确的方法?

推荐答案

您可以为每个正则表达式所需的操作定义一个函数，并执行类似的操作

You could define a function for the action required by each regex and do something like

def dostuff():
    stuff

def dootherstuff():
    otherstuff

def doevenmorestuff():
    evenmorestuff

actions = ((regex1, dostuff), (regex2, dootherstuff), (regex3, doevenmorestuff))

for regex, action in actions:
    m = re.match(regex, line)
    if m: 
        action()
        break

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