Replace ",**" with a linebreak using RegEx (or something else)

Question

I'm getting started with RegEx and I was wondering if anyone could help me craft a statement to convert coordinates as follows:

145.00694,-37.80421,9 145.00686,-37.80382,9 145.00595,-37.8035,16 145.00586,-37.80301,16

to

145.00694,-37.80421
145.00686,-37.80382
145.00595,-37.8035 
145.00586,-37.80301

(Strip off the last comma and value and turn it into a line break.)

I can't figure out how to use wildcards to do something like that. Any help would be greatly appreciated! Thanks.

Answer 1

>>> import re
>>> s="145.00694,-37.80421,9 145.00686,-37.80382,9 145.00595,-37.8035,16 145.00586,-37.80301,16"
>>> print re.sub(",\d*\w","\n",s)
145.00694,-37.80421
145.00686,-37.80382
145.00595,-37.8035
145.00586,-37.80301

Answer 2

"Some people, when confronted with a problem, think 'I know, I'll use regular expressions.' Now they have two problems." --Jamie Zawinski

Avoid that problem and use string methods:

s="145.00694,-37.80421,9 145.00686,-37.80382,9 145.00595,-37.8035,16 145.00586,37.80301,16"

lines = s.split(' ') # each line is separated by ' '
for line in lines:
    a,b,c=line.split(',') # three parts, separated by ','
    print a,b

Regex have their uses, but this is not one of them.

Answer 3

String methods seem to suffice here, regex are overkill:

>>> s='145.00694,-37.80421,9 145.00686,-37.80382,9 145.00595,-37.8035,16 145.00586,-37.80301,16'
>>> print('\n'.join(line.rpartition(',')[0] for line in s.split()))
145.00694,-37.80421
145.00686,-37.80382
145.00595,-37.8035
145.00586,-37.80301

Answer 4

>>> s = '145.00694,37.80421,9 145.00686,-37.80382,9 145.00595,-37.8035,16 145.00586,-37.80301,16
>>> patt = '(%s,%s),%s' % (('[+-]?\d+\.?\d*', )*3)
>>> m = re.findall(patt, s)   
>>> m
['145.00694,37.80421', '145.00686,-37.80382', '145.00595,-37.8035', '145.00586,-37.80301']
>>> print '\n'.join(m)
145.00694,37.80421
145.00686,-37.80382
145.00595,-37.8035
145.00586,-37.80301

but I prefer not use regular expressions in this case

I like SilentGhost solution