有条件的python正则表达式

Question

I am trying to parse the nmap output for service discovery with the following regex.

regex = "(?P<ports>[\d]+)\/(?P<protocol>tcp|udp)\s+(?P<state>open|filtered|closed)\s+(?P<service>[\w\S]*)\s+(?P<reason>\S*\s+\S+\s+\S*(?=\w)\w)(?:\n|(?P<version>.*))"

It could parse the output with the following pattern.

PORT    STATE    SERVICE    REASON         VERSION
80/tcp   open     http     str1 str2 str3    version string here

But is not able to correctly parse the following output.

PORT    STATE    SERVICE    REASON         VERSION
161/tcp filtered snmp       no-response

Is there any single regex which can parse both the above patterns?

Answer 1

You can add an alternative for hardcoded no-response , would it help?

(?P<ports>[\d]+)\/(?P<protocol>tcp|udp)\s+(?P<state>open|filtered|closed)\s+(?P<service>[\w\S]*)\s+(?P<reason>(:?\S*\s+\S+\s+\S*(?=\w)\w)|(:?no-response))(?:\n|(?P<version>.*))

Demo