[Tutor] Read from large text file, parse, find string, print string + line number to second text file.

[Steven D'Aprano]

On 02/02/13 15:31, Scurvy Scott wrote:
> One question related to the instruction aspect- does this make sense to you?
>
> If len(sys.argv) == 0:
>      print "usage: etc etc etc"


Right idea, but not quite correct.

sys.argv always includes at least one item, the name of the script being called. This is why you will often see code like this, to extract the actual arguments:


argv = sys.argv[1:]  # slice excluding the first item
if len(argv) == 0:
     usage()
else:
     main(argv)


or similar.


-- 
Steven