Python Generator Tricks

http://linuxgazette.net/100/pramode.html

43 14 16 years ago

Reading this item : http://news.ycombinator.com/item?id=1738906 : in which generators are discussed in comparison with the usual operations from functional programming languages, I was reminded of this article. Hence the submission.

metachris2• 16 years ago

Interesting post -- I've come to appreciate linuxgazette as a pretty good resource.

As a minor sidenote, I personally think 4 spaces for indentation makes the code more readable.

bmelton2• 16 years ago

I do almost all of my code editing in regular text editors, Vi or Notepad, usually. 4 spaces is impossible for me.

Why do you feel that 4 spaces is better than 5, which is usually the number of spaces represented by \t?

silvajoao2• 16 years ago

In my particular instance of the Universe, \t is usually represented by 8 spaces. I still prefer 4 though.

beambot• 16 years ago

The official "python style guide" dictates using 4 spaces for indentation (unless old / legacy code): http://www.python.org/dev/peps/pep-0008/

jgresula• 16 years ago

Here is a great practical intro to generators: Generator Tricks for Systems Programmers - http://www.dabeaz.com/generators-uk/GeneratorsUK.pdf

viraptor• 16 years ago

Here's also an interesting blog post from the creator of Diesel - http://blog.jamwt.com/2010/08/04/generators-and-back-again/ It's about using generators for trivial task scheduling.

praptak• 16 years ago

Python's own @contextmanager decorator ( http://docs.python.org/library/contextlib.html#contextlib.co... ) uses generators in quite a clever way. You can grok quite a lot about Python generators by trying to figure out what @contextmanager actually does under the hood.

adambyrtek• 16 years ago

The article is from 2004, so it doesn't mention modern features like generator expressions, context managers or co-routines (PEP 342). I suspect it was upvoted so much mostly because of the SICP reference.

gkelly• 16 years ago

It's also importing from __future__, which isn't necessary anymore.

bravura• 16 years ago

Please allow me to pickle simple generators. Otherwise, I have to go through all sorts of contortions:

   http://metaoptimize.com/blog/2009/12/22/why-cant-you-pickle-generators-in-python-workaround-pattern-for-saving-training-state/

Python Generator Tricks

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