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From: ram@zedat.fu-berlin.de (Stefan Ram)
Newsgroups: comp.lang.python
Subject: Re: Code improvement question
Date: 19 Nov 2023 10:04:06 GMT
Organization: Stefan Ram
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Expires: 1 Dec 2024 11:59:58 GMT
Message-ID: <regexp-20231119110325@ram.dialup.fu-berlin.de>
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ram@zedat.fu-berlin.de (Stefan Ram) writes:
>Thomas Passin <list1@tompassin.net> writes:
>>>>>>>> re.findall(r'\b[0-9]{2,7}-[0-9]{2}-[0-9]{2}\b', txt)
>Or,

def repeat_preceding( min=None, max=None, count=None ):
    ''' require that the preceding regexp is repeated
    a certain number of times, use either min and max
    or count '''
    return '{' + str( count )+ '}' if count else \
    '{' + str( min )+ ',' + str( max )+ '}'

digit = '[0-9]' # match a decimal digit
word_boundary = r'\b' # match a word boundary
a_hyphen = '-' # match a literal hyphen character

def digits( **kwargs ):
    ''' A certain number of digits. See 'repeat_preceding' for
    the possible kwargs. '''
    return digit + repeat_preceding( **kwargs )

def word( regexp: str ):
    ''' something that starts and ends with a word boundary '''
    return word_boundary + regexp + word_boundary

my_regexp = \
word \
( digits( min=2, max=7 ) + a_hyphen + 
  digits( count=2 ) + a_hyphen +
  digits( count=2 ))