Is there an easier way to express this list slicing?

John Henry john106henry at hotmail.com
Thu Nov 30 20:49:08 CET 2006


Paul McGuire wrote:
> "Paul McGuire" <ptmcg at austin.rr._bogus_.com> wrote in message
> news:MmGbh.10434$Gk5.6762 at tornado.texas.rr.com...
> > "John Henry" <john106henry at hotmail.com> wrote in message
> > news:1164913125.509492.54060 at 79g2000cws.googlegroups.com...
> snip
>
> Grrrr... that's what I get for not keeping editor and interpreter windows in
> sync.  My post was referencing vars I had defined in the interpreter, but
> which the function had no clue of. !!!  Here's a working version.
>
> -- Paul
>
>
> def splitUp(src,lens):
>     ret = []
>     cur = 0
>     for length in lens:
>         if length is not None:
>             ret.append( src[cur:cur+length] )
>             cur += length
>         else:
>             ret.append( src[cur:] )
>     return ret
>
> origlist = list("ABCDEFGHIJ")
> alist, blist, clist, dlist = splitUp( origlist, (1,1,3,None) )
> print alist, blist, clist, dlist


Nice.

While we are at it, why not:

class splitUp(object):
   def __init__(self,src):
       self._src=list(src)
   def slice(self, lens):
     ret = []
     cur = 0
     for length in lens:
         if length is not None:
             ret.append( self._src[cur:cur+length] )
             cur += length
         else:
             ret.append( self._src[cur:] )
     return ret

alist, blist, clist, dlist = splitUp("ABCDEFGHIJ").slice((1,1,3,None))
print alist, blist, clist, dlist

Now, that's readable!




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