Regex to extract top level domain from email address

Question

From email address like

xxx@site.co.uk
xxx@site.uk
xxx@site.me.uk

I want to write a regex which should return 'uk' is all the cases.

I have tried

'+@([^.]+)\..+'

which gives only the domain name. I have tried using

'[^/.]+$'

but it is giving error.

What error are you getting for the last one? And could you show the actual code you're using? — Jerry, Apr 01 '14 at 12:03
Is a regex necessary? How about `email_address.rsplit(".", 1)[1]`? — Blckknght, Apr 01 '14 at 12:10
This is part of big code, which supports regex only. But somehow `\w+$` is working, thnks @UlugbekUmirov — amitbisai, Apr 01 '14 at 12:47
@amitbisai Your second regex is almost correct. You just used wrong escaping symbol. It should be `\`` - `[^\.]+$`. — Ulugbek Umirov, Apr 01 '14 at 13:02

Ammar · Answer 1 · 2014-04-01T12:24:12.453

The regex to extract what you are asking for is:

\.([^.\n\s]*)$  with /gm modifiers

explanation:

    \. matches the character . literally
1st Capturing group ([^.\n\s]*)
    [^.\n\s]* match a single character not present in the list below
        Quantifier: Between zero and unlimited times, as many times as possible, giving back as needed [greedy]
        . the literal character .
        \n matches a fine-feed (newline) character (ASCII 10)
        \s match any white space character [\r\n\t\f ]
$ assert position at end of a line
m modifier: multi-line. Causes ^ and $ to match the begin/end of each line (not only begin/end of string)
g modifier: global. All matches

for your input example, it will be:

import re
m = re.compile(r'\.([^.\n\s]*)$', re.M)                                             
f = re.findall(m, data)                                                             
print f

output:

['uk', 'uk', 'uk']

hope this helps.

score 2 · Answer 2 · answered Apr 01 '14 at 12:18

2

As myemail@com is a valid address, you can use:

@.*([^.]+)$

answered Apr 01 '14 at 12:18

Toto

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score 2 · Answer 3 · answered Apr 01 '14 at 19:57

2

You don't need regex. This would always give you 'uk' in your examples:

>>> url = 'foo@site.co.uk'
>>> url.split('.')[-1]
'uk'

answered Apr 01 '14 at 19:57

alan

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score 0 · Answer 4 · edited Apr 01 '14 at 13:54

0

Simply .*\.(\w+) won't help?

Can add more validations for "@" to the regular expression if needed.

edited Apr 01 '14 at 13:54

Jeroen

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answered Apr 01 '14 at 12:51

Murli

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Regex to extract top level domain from email address

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