first, regex part:
I am new to regexes and have come up with the following expression:
((1[0-4]|[1-9]),(1[0-4]|[1-9])/){5}(1[0-4]|[1-9]),(1[0-4]|[1-9])
to exactly match strings which look like this:
1,2/3,4/5,6/7,8/9,10/11,12
i.e. 6 comma-delimited pairs of integer numbers separated by the
backslash character + constraint that numbers must be in range 1-14.
i should add that i am only interested in finding exact matches (doing
some kind of command line validation).
this seems to work fine, although i would welcome any advice about how
to shorten the above. it seems to me that there should exist some
shorthand for (1[0-4]|[1-9]) once i have defined it once?
also (and this is where my total beginner status brings me here
looking for help :)) i would like to add one more constraint to the
above regex. i want to match strings *iff* each pair of numbers are
different. e.g: 1,1/3,4/5,6/7,8/9,10/11,12 or
1,2/3,4/5,6/7,8/9,10/12,12 should fail to be matched by my final
regex whereas 1,2/3,4/5,6/7,8/9,10/11,12 should match OK.
any tips would be much appreciated - especially regarding preceding
paragraph!
and now for the python part:
results = "1,2/3,4/5,6/7,8/9,10/11,12"
match = re.match("((1[0-4]|[1-9]),(1[0-4]|[1-9])/){5}(1[0-4]|[1-9]),
(1[0-4]|[1-9])", results)
if match == None or match.group(0) != results:
raise FormatError("Error in format of input string: %s" %
(results))
results = [leg.split(',') for leg in results.split('/')]
# => [['1', '2'], ['3', '4'], ['5', '6'], ['7', '8'], ['9', '10'],
['11', '12']]
.
.
.
the idea in the above code being that i want to use the regex match as
a test of whether or not the input string (results) is correctly
formatted. if the string results is not exactly matched by the regex,
i want my program to barf an exception and bail out. apart from
whether or not the regex is good idiom, is my approach suitably
pythonic?
TIA for any help here.
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