haystack1 = '''**GS***RL*CITGO*JJ*20090518*1036*25110*X*00405
ST*423*2511*RT**GS***08247'''
haystack2 = '''**#**UPT     0000SWSAM001203081454NS      /
GS*QM*TRSC*UPDS  *20120309*0820*0309***#***004010'''
 
fail3 = 'G#' # should only match the '#'
 
import re
needle = re.compile(r'GS|#')
 
def test(**kwargs):
    for k, v in kwargs.items():
        m = needle.search(v)
        if m:
            print '{name}: {chars} characters at {start}..{end}'.format(name=k, start=m.start(), end=m.end(), chars=len(m.group()))
        else:
            print '{name}: no match'.format(name=k)
 
test(haystack1=haystack1, haystack2=haystack2, fail3=fail3)

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