Using variables in Python regular expression [duplicate]

This question already has answers here: How to use a variable inside a regular expression? (12 answers) Closed 2 years ago.

I'm parsing a file and looking in the lines for userna开发者_如何学运维me-# where the username will change and there can be any number of digits [0-9] after the dash.

I have tried nearly every combination trying to use the variable username in the regular expression.

Am I even close with something like re.compile('%s-\d*'%user)?

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Working as it should:

>>> user = 'heinz'
>>> import re
>>> regex = re.compile('%s-\d*'%user)
>>> regex.match('heinz-1')
<_sre.SRE_Match object at 0x2b27a18e3f38>
>>> regex.match('heinz-11')
<_sre.SRE_Match object at 0x2b27a2f7c030>
>>> regex.match('heinz-12345')
<_sre.SRE_Match object at 0x2b27a18e3f38>
>>> regex.match('foo-12345')

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You could create the string using .format() method of string:

re.compile('{}-\d*'.format(user))

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Yes, concatenate the regex yourself, or use string formatting. But don't forget to use re.escape() if your variable could contain characters that have special meaning in regular expressions.

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What about:

re.compile(user + '-\d*')