[Python-Dev] string find(substring) vs. substring in string

Batista, Facundo FBatista at uniFON.com.ar
Wed Feb 16 21:23:59 CET 2005


[Fredrik Lundh]

#- any special reason why "in" is faster if the substring is found, but
#- a lot slower if it's not in there?

Maybe because it stops searching when it finds it?

The time seems to be very dependant of the position of the first match:

  fbatista at pytonisa ~/ota> python /usr/local/lib/python2.3/timeit.py -s "s =
'not there'*100" "'not there' in s"
  1000000 loops, best of 3: 0.222 usec per loop

  fbatista at pytonisa ~/ota> python /usr/local/lib/python2.3/timeit.py -s "s =
'blah blah'*20 + 'not there'*100" "'not there' in s"
  100000 loops, best of 3: 5.54 usec per loop

  fbatista at pytonisa ~/ota> python /usr/local/lib/python2.3/timeit.py -s "s =
'blah blah'*40 + 'not there'*100" "'not there' in s"
  100000 loops, best of 3: 10.8 usec per loop


.    Facundo

Bitácora De Vuelo: http://www.taniquetil.com.ar/plog
PyAr - Python Argentina: http://pyar.decode.com.ar/



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