471,349 Members | 1,438 Online
Bytes | Software Development & Data Engineering Community
Post +

Home Posts Topics Members FAQ

Join Bytes to post your question to a community of 471,349 software developers and data experts.

regex with specific list of string

hi,

how do I regex that could check on any of the value that match any one
of these ... 'jan', 'feb', 'mar', 'apr', 'may', 'jun', 'jul', 'aug',
'sep', 'oct', 'nov', 'dec'

Thanks
james

Sep 26 '07 #1
8 6219
On Wed, 2007-09-26 at 15:42 +0000, james_027 wrote:
hi,

how do I regex that could check on any of the value that match any one
of these ... 'jan', 'feb', 'mar', 'apr', 'may', 'jun', 'jul', 'aug',
'sep', 'oct', 'nov', 'dec'
Why regex? You can simply check if the given value is contained in the
set of allowed values:
>>s = set(['jan', 'feb', 'mar', 'apr', 'may', 'jun', 'jul', 'aug',
'sep', 'oct', 'nov', 'dec'])
>>'jan' in s
True
>>'spam' in s
False

HTH,

--
Carsten Haese
http://informixdb.sourceforge.net
Sep 26 '07 #2
james_027 wrote:
hi,

how do I regex that could check on any of the value that match any one
of these ... 'jan', 'feb', 'mar', 'apr', 'may', 'jun', 'jul', 'aug',
'sep', 'oct', 'nov', 'dec'

Thanks
>>patr = re.compile('jan|feb|mar|apr|may|jun|jul|aug|sep|no v|oct|dec')
patr.match("jul")
<_sre.SRE_Match object at 0x7ff28ad8>
>>patr.match("nosuch")
regards
Steve
--
Steve Holden +1 571 484 6266 +1 800 494 3119
Holden Web LLC/Ltd http://www.holdenweb.com
Skype: holdenweb http://del.icio.us/steve.holden

Sorry, the dog ate my .sigline

Sep 26 '07 #3
Carsten Haese wrote:
On Wed, 2007-09-26 at 15:42 +0000, james_027 wrote:
>hi,

how do I regex that could check on any of the value that match any one
of these ... 'jan', 'feb', 'mar', 'apr', 'may', 'jun', 'jul', 'aug',
'sep', 'oct', 'nov', 'dec'

Why regex? You can simply check if the given value is contained in the
set of allowed values:

>>>s = set(['jan', 'feb', 'mar', 'apr', 'may', 'jun', 'jul', 'aug',
'sep', 'oct', 'nov', 'dec'])
>>>'jan' in s
Also, check calendar for a locale aware (vs hardcoded) version:
>>import calendar
[calendar.month_abbr[i].lower() for i in range(1,13)]
['jan', 'feb', 'mar', 'apr', 'may', 'jun', 'jul', 'aug', 'sep', 'oct', 'nov', 'dec']

If you still want to use regexes, you can do something like:
>>import re
pattern = '(?:%s)' % '|'.join(calendar.month_abbr[1:13])
pattern
'(?:Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|De c)'
>>re.search(pattern, "we are in september", re.IGNORECASE)
<_sre.SRE_Match object at 0xb7ced640>
>>re.search(pattern, "we are in september", re.IGNORECASE).group()
'sep'

If you want to make sure that the month name begins a word, use the following pattern instead:
>>pattern = r'(?:\b%s)' % r'|\b'.join(calendar.month_abbr[1:13])
pattern
'(?:\\bJan|\\bFeb|\\bMar|\\bApr|\\bMay|\\bJun|\\bJ ul|\\bAug|\\bSep|\\bOct|\\bNov|\\bDec)'

If in doubt, Google for "regular expressions in python" or go to http://docs.python.org/lib/module-re.html
Regards,
Pablo

Sep 26 '07 #4
On Wed, 2007-09-26 at 12:49 -0400, Steve Holden wrote:
james_027 wrote:
hi,

how do I regex that could check on any of the value that match any one
of these ... 'jan', 'feb', 'mar', 'apr', 'may', 'jun', 'jul', 'aug',
'sep', 'oct', 'nov', 'dec'

Thanks
>>patr = re.compile('jan|feb|mar|apr|may|jun|jul|aug|sep|no v|oct|dec')
>>patr.match("jul")
<_sre.SRE_Match object at 0x7ff28ad8>
>>patr.match("nosuch")
Unfortunately, that also matches margarine, mayonnaise, and octopus,
just to name a few ;-)

--
Carsten Haese
http://informixdb.sourceforge.net
Sep 26 '07 #5
Carsten Haese wrote:
On Wed, 2007-09-26 at 12:49 -0400, Steve Holden wrote:
>james_027 wrote:
>>hi,

how do I regex that could check on any of the value that match any one
of these ... 'jan', 'feb', 'mar', 'apr', 'may', 'jun', 'jul', 'aug',
'sep', 'oct', 'nov', 'dec'

Thanks
patr = re.compile('jan|feb|mar|apr|may|jun|jul|aug|sep|no v|oct|dec')
patr.match("jul")
<_sre.SRE_Match object at 0x7ff28ad8>
> >>patr.match("nosuch")

Unfortunately, that also matches margarine, mayonnaise, and octopus,
just to name a few ;-)
Indeed, but I think the essential point was served. Unlike the
mayonnaise and octopus.

regards
Steve
--
Steve Holden +1 571 484 6266 +1 800 494 3119
Holden Web LLC/Ltd http://www.holdenweb.com
Skype: holdenweb http://del.icio.us/steve.holden

Sorry, the dog ate my .sigline

Sep 26 '07 #6
Carsten Haese wrote:
On Wed, 2007-09-26 at 12:49 -0400, Steve Holden wrote:
>james_027 wrote:
>>hi,

how do I regex that could check on any of the value that match any one
of these ... 'jan', 'feb', 'mar', 'apr', 'may', 'jun', 'jul', 'aug',
'sep', 'oct', 'nov', 'dec'

Thanks
patr = re.compile('jan|feb|mar|apr|may|jun|jul|aug|sep|no v|oct|dec')
patr.match("jul")
<_sre.SRE_Match object at 0x7ff28ad8>
>>patr.match("nosuch")

Unfortunately, that also matches margarine, mayonnaise, and octopus,
just to name a few ;-)
(and so does the solution you sent before :)

This is fine IMO since the OP didn't specify the opposite.

BTW in my previous post I included an example that ensures that the
search month matches the beginning of a word. That was based in that
maybe he wanted to match e.g. "dec" against "December" (BTW, it should
have been r'\b(?:Jan|Feb|...)' instead). To always match a whole word, a
trailing \b can be added to the pattern OR (much better) if the month
can appear both in its abbreviated and full form, he can use the
extensive set as follows (I hope this is clear, excuse my Thunderbird...):
>>pattern = r"\b(?:%s)\b" % '|'.join(calendar.month_name[1:13] +
calendar.month_abbr[1:13])
>>pattern
'\\b(?:January|February|March|April|May|June|July| August|September|October|November|December|Jan|Feb |Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec)\\b'
>>target = "Unlike Julia, I like apricots with mayo in august or sep"
target
'Unlike Julia, I like apricots with mayo in august or sep'
>>re.findall(pattern, target, re.IGNORECASE)
['august', 'sep']
>>re.search(pattern, target, re.IGNORECASE)
<_sre.SRE_Match object at 0xb7ced640>
>>re.findall(pattern, target, re.IGNORECASE)
['august', 'sep']
Regards,
Pablo
Sep 26 '07 #7
Hi all,
This is fine IMO since the OP didn't specify the opposite.
Thanks for all your replies, though I don't understand quite well the
going argument? What do you mean when you say "the OP didn't specify
the opposite"?

There reason for using regex is because I am going to use it in
Django's URL pattern

Thanks
james

Sep 26 '07 #8
james_027 wrote:
Hi all,
>This is fine IMO since the OP didn't specify the opposite.

Thanks for all your replies, though I don't understand quite well the
going argument? What do you mean when you say "the OP didn't specify
the opposite"?

There reason for using regex is because I am going to use it in
Django's URL pattern
Carsten was pointing out that the pattern I gave you would match any
string that *began* with one of the month names, as I didn't include an
element to force a match of the end of the string.

I did this because I assumed you were most interested in finding out how
to match one of a number of alternate strings, and this would likely
only be a part of your final pattern.

If you already have what you need you really don't need to pay much
attention to the rest: it's just geeks picking nits!

regards
Steve
--
Steve Holden +1 571 484 6266 +1 800 494 3119
Holden Web LLC/Ltd http://www.holdenweb.com
Skype: holdenweb http://del.icio.us/steve.holden

Sorry, the dog ate my .sigline

Sep 26 '07 #9

This discussion thread is closed

Replies have been disabled for this discussion.

Similar topics

3 posts views Thread by Timmy | last post: by
2 posts views Thread by FrzzMan | last post: by
3 posts views Thread by slg | last post: by
2 posts views Thread by KK | last post: by
2 posts views Thread by =?Utf-8?B?REFSVDQz?= | last post: by
reply views Thread by XIAOLAOHU | last post: by

By using Bytes.com and it's services, you agree to our Privacy Policy and Terms of Use.

To disable or enable advertisements and analytics tracking please visit the manage ads & tracking page.