problem with lists

[Manuel Hendel]

I want to create a list of domains, every domain only once.

So long I did the following, but it didn't work:

#!/usr/bin/env python
#
import sys, string, re

inputfile = open(sys.argv[-1], "r")

lines = inputfile.readlines()
lines = lines[3:]

for line in lines:
        line = string.strip(line)[1:-1]
        fields = string.split(line, "|")

        domains = []

        if not domains.index(fields[3:4]):
            domains.append(fields[3:4])

print domains

This brings the following error message:

:!./pop3create.py pop3data
[No write since last change]
Traceback (most recent call last):
File "./pop3create.py", line 22, in ?
if domains.index(fields[3:4]):
ValueError: list.index(x): x not in list

Can someone explain this to me?

Thanks,
    Manuel

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Immature love says, "I love you because I need you." Mature love says, "I need 
you because I love you." 
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