[Python-Dev] PEP 289 - Generator Expressions (original) (raw)

[Python-Dev] PEP 289 - Generator Expressions - Let's Move Forward

Jeremy Hylton jeremy at alum.mit.edu
Fri Apr 23 16:10:39 EDT 2004

On Fri, 2004-04-23 at 15:59, Phillip J. Eby wrote:

At 03:41 PM 4/23/04 -0400, Jeremy Hylton wrote:

>That leads me to wonder what exactly the rationale for generator >expressions is. The PEP says that "time, clarity, and memory are >conserved by using an generator expression" but I can only see how >memory is conserved. That is, I don't find them any easier to read than >list comprehensions and I don't understand the performance implications >very well. It's not obvious to me that their faster. Alex Martelli previously posted some tests that showed them to be quite a bit faster for large lists.

Anyone know where to find these numbers. I've done some searching, but I can't find them. It would be good to include something concrete in the PEP.

Jeremy

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