better for-loop syntax for detecting empty sequences?
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                Dmitry Beransky
            
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        Published on 2010-12-29T19:42:14Z
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            2010/12/29
            19:54 UTC
        
        
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Hi,
Is there a better way to write the following:
   row_counter = 0
   for item in iterable_sequence:
      # do stuff with the item
      counter += 1
   if not row_counter:
      # handle the empty-sequence-case
Please keep in mind that I can't use len(iterable_sequence) because 1) not all sequences have known lengths; 2) in some cases calling len() may trigger loading of the sequence's items into memory (as the case would be with sql query results).
The reason I ask is that I'm simply curious if there is a way to make above more concise and idiomatic. What I'm looking for is along the lines of:
for item in sequence:
   #process item
*else*:
   #handle the empty sequence case
(assuming "else" here worked only on empty sequences, which I know it doesn't)
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