"Stringizing" a list

[Mike Fletcher]

Something like the following:

import types
allowedMap = { types.ListType:1, types.TupleType:1 }

You could also add classes that have "for" interfaces to get them expanded
along with the lists/tuples. Alternately, you could leave off the tuples if
you only want to expand lists.

Incidentally, here's my original version, which was much simpler :) 

def collapse(inlist, type=type, ltype=types.ListType, maxint= sys.maxint):
	'''
	Destructively flatten a list hierarchy to a single level. 
	Non-recursive, and (as far as I can see, doesn't have any
	glaring loopholes).
	Further speedups and obfuscations by Tim Peters :)
	'''
	try:
		# for every possible index
		for ind in xrange( maxint):
			# while that index currently holds a list
			while type(inlist[ind]) is ltype:
				# expand that list into the index (and
subsequent indicies)
				inlist[ind:ind+1] = inlist[ind]
			#ind = ind+1
	except IndexError:
		pass
	return inlist

def collapse_safe(inlist):
	'''
	As collapse, but works on a copy of the inlist
	'''
	return collapse( inlist[:] )

Enjoy,
Mike

-----Original Message-----
From: Peter Schneider-Kamp [mailto:nowonder at nowonder.de]
Sent: Wednesday, August 09, 2000 5:43 PM
To: Mike Fletcher
Cc: 'cg at cdegroot.com'; Python Listserv (E-mail)
Subject: Re: "Stringizing" a list


Mike Fletcher wrote:
> 
> Something like
>         string.join(hyperCollapse( data))
> 
> Should be fairly fast and general.

If it would work. What has to supplied as allowedmap?
hyperCollapse requires 2 parameters.

Peter
--
Peter Schneider-Kamp          ++47-7388-7331
Herman Krags veg 51-11        mailto:peter at schneider-kamp.de
N-7050 Trondheim              http://schneider-kamp.de

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