"John Machin" <[EMAIL PROTECTED]> wrote in message news:[EMAIL PROTECTED] > Markus wrote: > > You know you're guilty of early/over optimisation, when it's almost two > > in the morning and the file open in front of you reads as follows. > > <snip> > > > > from timeit import Timer > > > > if __name__=='__main__': > > t = Timer('len(argv)==1','from sys import argv') > > print "%f usec/pass" % (1000000 * t.timeit(number=100000)/100000) > > t = Timer('argv[0]==argv[-1]','from sys import argv') > > print "%f usec/pass" % (1000000 * t.timeit(number=100000)/100000) > > > > [-snip-]
You're worried about the performance of len(sys.argv)?! Is your command line processing *really* your program bottleneck? If so, I'd say making a better len is the least of your problems. Hard to imagine you'll do better than len, especially for lists as short as command line args. If you are *really* doing lots of len'ning, copy len to a local to cut down on lookup costs: C:\Documents and Settings\Paul>python -mtimeit -s"a=['abc','abc']" "len(a)" 1000000 loops, best of 3: 0.218 usec per loop C:\Documents and Settings\Paul>python -mtimeit -s"a=['abc','abc'];len_=len" "len_(a)" 10000000 loops, best of 3: 0.172 usec per loop But honestly, do some profiling before adding these maintenance-hindering and readability-impairing "optimizations." -- Paul -- http://mail.python.org/mailman/listinfo/python-list
