On Jan 11, 8:55 pm, "Reedick, Andrew" <[EMAIL PROTECTED]> wrote:
> > -----Original Message-----
> > From: [EMAIL PROTECTED] [mailto:python-
> > [EMAIL PROTECTED] On Behalf Of cesco
> > Sent: Wednesday, January 09, 2008 5:34 AM
> > To: [EMAIL PROTECTED]
> > Subject: alternating string replace
>
> > Hi,
>
> > say I have a string like the following:
> > s1 = 'hi_cat_bye_dog'
> > and I want to replace the even '_' with ':' and the odd '_' with ','
> > so that I get a new string like the following:
> > s2 = 'hi:cat,bye:dog'
> > Is there a common recipe to accomplish that? I can't come up with any
> > solution...
>
> For those of us who still think in Perl, here's an easy to read, lazy
> solution:
>
> s = 'hi_cat_bye_dog'
> print s
> s = re.sub(r'_(.*?(_|$))', r':\1', s) ## every odd '_' to ':'
> print s
> s = re.sub(r'_', r',', s) ## every even '_' to ','
> print s
>
> > hi_cat_bye_dog
> > hi:cat_bye:dog
> > hi:cat,bye:dog
>
> The equivalent Perl code:
> my $s = 'hi_cat_bye_dog';
>
> print $s, "\n";
> $s =~ s/_(.*?(_|$))/:$1/g;
> print $s, "\n";
> $s =~ s/_/,/g;
> print $s, "\n";
def altrep8(s):
import re
s = re.sub(r'_(.*?(_|$))', r':\1', s) ## every odd '_' to ':'
return re.sub(r'_', r',', s) ## every even '_' to ','
altrep8.author="Reedick, Andrew"
Gives:
## Program by: Reedick, Andrew
'' RETURNS ''
'1' RETURNS '1'
'2_' RETURNS '2:'
'3_4' RETURNS '3:4'
'5_6_' RETURNS '5:6,'
'7_8_9' RETURNS '7:8,9'
'10_11_12_' RETURNS '10:11,12:'
'13_14_15_16' RETURNS '13:14,15:16'
'17_18_19_20_' RETURNS '17:18,19:20,'
'_' RETURNS ':'
'_21' RETURNS ':21'
'_22_' RETURNS ':22,'
'_23_24' RETURNS ':23,24'
'_25_26_' RETURNS ':25,26:'
'_27_28_29' RETURNS ':27,28:29'
'_30_31_32_' RETURNS ':30,31:32,'
'_33_34_35_36' RETURNS ':33,34:35,36'
'__' RETURNS ':,'
'___' RETURNS ':,:'
'____' RETURNS ':,:,'
'_____' RETURNS ':,:,:'
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