CODEWITHSUNDEEP
pythonarrayslistlist-comprehension
diplosaurus
diplosaurus

Reputation: 2588

Python list comprehension nested loop

Right now I'm "removing" emails from a list by mapping a new list excluding the things I don't want. This looked like:

    pattern = re.compile('b\.com')

    emails = ['[email protected]', '[email protected]', '[email protected]', '[email protected]']
    emails = [e for e in emails if pattern.search(e) == None]
    # resulting list:  ['[email protected]', '[email protected]']

However, now I need to filter out multiple domains, so I have a list of domains that need to be filtered out.

    pattern_list = ['b.com', 'c.com']

Is there a way to do this still in list comprehension form or am I going to have to revert back to nested for loops?

Note: splitting the string at the @ and doing word[1] in pattern_list won't work because c.com needs to catch sub.c.com as well.

Upvotes: 2

Views: 178

Answers (2)

BrenBarn
BrenBarn

Reputation: 251598

There are a few ways to do this, even without using a regex. One is:

[e for e in emails if not any(pat in e for pat in pattern_list)]

This will also exclude emails like [email protected] and [email protected], but so does your original solution. It does not, however, exclude cases like user@bocom, which your existing solution does. Again, it's not clear if your existing solution actually does what you think it does.

Another possibility is to combine your patterns into one with rx = '|'.join(pattern_list) and then match on that regex. Again, though, you'll need to use a more complex regex if you want to only match b.com as a full domain (not as just part of the domain or as part of the username).

Upvotes: 2

abhishekgarg
abhishekgarg

Reputation: 1473

import re

pattern = re.compile('b.com$|c.com$')

emails = ['[email protected]', '[email protected]', '[email protected]', '[email protected]']

emails = [e for e in emails if pattern.search(e) == None]

print emails

what about this

Upvotes: 2

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