CODEWITHSUNDEEP
pythonregex
helloworld1234
helloworld1234

Reputation: 327

Python regex to exclude email pattern but include @string pattern

Consider I have the string of the following:

string = "Hello, please send message to @david, @nick, @jack, but do not send message to any email address like [email protected] or [email protected], thanks!"
matches = re.findall("\@\w+", string)
print(macthes)

#return ['@david', '@nick', '@jack', '@google', '@yahoo']

However, I would only want to return ['@david', '@nick', '@jack']

How can I exclude the pattern for email address so that it only return me the name tag using @. Thanks.

Upvotes: 1

Views: 240

Answers (1)

Wiktor Stribiżew
Wiktor Stribiżew

Reputation: 626689

Since emails contain a word char before @ you may use \B:

r'\B@\w+'

The \B here matches at the start of the string or if there is a non-word char before @ (punctuation other than _ or whitespace). See the regex demo.

If you know the strings you need to extract are after whitespace/start of string use

r'(?<!\S)@\w+'

The (?<!\S) negative lookahead fails the match if there is no whitespace immediately to the left of the current location. Hence, @\w+ only matches at the start of the string or after a whitespace. See this regex demo.

Python demo:

import re    
s = 'Hello, please send message to @david, @nick, @jack, but do not send message to any email address like [email protected] or [email protected], thanks!'
print( re.findall(r'\B@\w+', s) )
# => ['@david', '@nick', '@jack']
print( re.findall(r'(?<!\S)@\w+', s) )
# => ['@david', '@nick', '@jack']

Upvotes: 2

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