No strides? (was Re: List mapping?)

David Smith drs at labs.agilent.com
Fri Apr 14 20:12:13 CEST 2000


Why aren't strides implemented for slices of lists and tuples?  I would
have liked to suggest

	map( None, a[0::2], a[1::2] )

			David Smith


Nick Trout wrote:
> 
> Is there a nice way of pairing up the members to form tuple pairs in another
> list? ie. like you might to processing input args.
> 
> ie. changing ['/a','1','/b','2','/c','3'] into [ ('/a','1'), ('/b','2'),
> ('/c','3') ]
> 
> eg:
> 
> args = '/a 1 /b 2 /c 3'
> listargs= string.split(args)
> tuplist = []
> i=0
> while i < len(listargs):
>     tuplist.append( (listargs[i],listargs[i+1]) )
>     i = i+2
> for i in tuplist:
>     processargs(i)
> 
> or:
> 
> args = '/a 1 /b 2 /c 3'
> for i in string.split(args):
>     i = argflag
>     # i want next arg now as a parameter!!!
> 
> Can I (you!) get rid of the long winded while loop cleverly?!!  :-)
> 
> Thanks in advance,
> Nick.



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