CODEWITHSUNDEEP
pythonregexstring
roger
roger

Reputation: 9933

python regex can not match if newline exists in string?

I am using regex to find time in a string:

re.match('.*(\d{2}-\d{2} \d{2}:\d{2})', "09-22 13:27")

anyway, this is ok, but if \n exists, this return None:

re.match('.*(\d{2}-\d{2} \d{2}:\d{2})', "\n09-22 13:27")

so why .* can not match \n? and how to deal with this?

Upvotes: 0

Views: 574

Answers (3)

LetzerWille
LetzerWille

Reputation: 5668

You can exclude newline by using (? 

st =  "\n\n09-22 13:27\n"
import re
mo = re.findall(r'(?<!\S)\d{2}-\d{2}\D+\d{2}:\d{2}(?!\S)',st)
print(mo)

Results in:

['09-22 13:27']

Upvotes: 1

vks
vks

Reputation: 67988

print re.match('.*(\d{2}-\d{2} \d{2}:\d{2})', "\n09-22 13:27".strip())

                                                              ^^^^^^^^

You can simply strip the newline.

Upvotes: 0

Wiktor Stribiżew
Wiktor Stribiżew

Reputation: 627468

why .* can not match \n? and how to deal with this?

re documentation says:

re.DOTALL
Make the . special character match any character at all, including a newline; without this flag, . will match anything except a newline.

You should note that . matches any symbol but a newline. Use re.S (re.DOTALL) flag to match a newline with .:

import re
obj = re.match('.*(\d{2}-\d{2} \d{2}:\d{2})', "\n09-22 13:27", re.S)
if obj:
    print(obj.group(1))

See IDEONE demo

Upvotes: 4

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