Generator Comprehensions

Oren Tirosh oren-py-l at
Tue Jan 29 05:50:38 EST 2002

On Mon, Jan 28, 2002 at 09:29:46PM -0500, Raymond Hettinger wrote:
> Wild idea of the day:  Extend the syntax for list comprehensions
> to have an optional 'yield' to create a generator rather than a list.
> sizegen = [ yield (len(line),line) for line in file.readline() ]

I like it.  Reusing the yield keyword is a very elegant solution.

One problem with this syntax is that there is no justification for the use
of square brackets - the result isn't a list.  It looks like it can work 
just fine without them.  The keyword yield can work similarly to the 
lambda keyword.  It would have a priority just between lambda and boolean 


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