PEP 289: Generator Expressions (please comment)

Bruno Desthuilliers bdesth.nospam at removeme.free.fr
Fri Nov 7 07:22:50 EST 2003


Raymond Hettinger wrote:
> 
>     http://www.python.org/peps/pep-0289.html
> 
> In brief, the PEP proposes a list comprehension style syntax for
> creating fast, memory efficient generator expressions on the fly:
> 
>     sum(x*x for x in roots)
>     min(d.temperature()*9/5 + 32 for d in days)
>     Set(word.lower() for word in text.split() if len(word) < 5)
>     dict( (k, somefunc(k)) for k in keylist )
>     dotproduct = sum(x*y for x,y in itertools.izip(xvec, yvec))
>     bestplayer, bestscore = max( (p.score, p.name) for p in players )
> 
> Each of the above runs without creating a full list in memory,
> which saves allocation time, conserves resources, and exploits
> cache locality.
> 

+3.1415926535897931 for me.

Bruno





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