Lists and Indices

Jim Meier jim at dsdd.org
Fri Aug 9 05:39:09 CEST 2002


On Thu, 08 Aug 2002 06:45:39 -0600, Mark McEahern wrote:

>> I currently use
>>
>> index=1
>> for color in colors:
>>     print '%d.  %s' % (index, color)
>>     index += 1
>>
>> but that does not seem pretty to me;

If you feel the need, try something like this:

>>> class IndexingIterator:
... 	def __init__(self, iterator):
... 		self.index = 0
... 		self.iter = iter(iterator)
... 	def __iter__(self):
... 		return self
... 	def next(self):
... 		self.index += 1
... 		return (self.index, self.iter.next())
... 
>>> for i,c in IndexingIterator(['a','b','c']):
... 	print "%d. %s" % (i,c)
... 
1. a
2. b
3. c
>>>^D

"IndexingIterator" is a mouthful, you'd probably want to choose a better
name.

-Jim








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