Pls, help me with re

Eric Brunel eric.brunel at pragmadev.com
Mon Mar 3 11:20:50 CET 2003


Lexy Zhitenev wrote:
> Hi, All.
> 
> I want to match a number if it is the only one in the string, and the second
> one, if '=' preceeds it.
> 
> Example
> 
> 'Course: 23,95' - matches '23,95'
> '$1 = 23,95 y' - matches '23,95'.

So what you want is the following:
- either a sequence of characters that are not equal signs, digits or commas, 
followed by a number, followed by a group of characters that are not equal 
signs, digits or commas
- or a group of any characters, followed by an equal sign, followed by a group 
of characters that are not digits or commas, followed by a number, followed by 
anything

Is that correct?

If it is, here is my solution:

-----------------------------------------------
import re
myREs = {
   'notEqualsDigitsOrCommas' : '[^=0-9,]',
   'number'                  : '[0-9]+(?:,[0-9]*)?',
   'notDigitOrCommas'        : '[^0-9]'
}
ptn1 = \
   "^%(notEqualsDigitsOrCommas)s*(%(number)s)%(notEqualsDigitsOrCommas)s*$" \
   % myREs
ptn2 = "^.*=%(notDigitOrCommas)s*(%(number)s)" % myREs
ptn = "%s|%s" % (ptn1, ptn2)

print re.match(ptn, 'Course: 23,95').groups()
print re.match(ptn, '$1 = 23,95 y').groups()
-----------------------------------------------

HTH
-- 
- Eric Brunel <eric.brunel at pragmadev.com> -
PragmaDev : Real Time Software Development Tools - http://www.pragmadev.com





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