positional modifiers in python?

Eric Brunel eric.brunel at pragmadev.com
Fri Jun 7 13:52:19 EDT 2002

fuf wrote:
>  hello everyone,
>  does python support positional parameters in the print method? ie.
>  something like:
>     print "there %2$s something %1$s" % ("there", "is")
>  it doesn't work but maybe there's some other way?

There's an utterly ugly way to do this:

def toPosDict(l):
  d = {}
  map(lambda k,v,d=d: d.update({str(k):v}), range(len(l)), l)
  return d
print "there %(1)s something %(0)s" % toPosDict(("there", "is"))

For post-Python 2.2 users (I'm still 2.1, sorry), the "map" line may 
certainly be replaced by:

map(d.__setitem__, [str(i) for i in range(len(l))], l)

but it may be less efficient than the code above (one map + one list 
comprehension instead of a single map in the first solution). Maybe the 
second's a little more readable (or a little less unreadable ;-).

- Eric Brunel <eric.brunel at pragmadev.com> -
PragmaDev : Real Time Software Development Tools - http://www.pragmadev.com

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