The rap against "while True:" loops
Hendrik van Rooyen
hendrik at microcorp.co.za
Mon Oct 19 02:51:44 EDT 2009
On Sunday, 18 October 2009 11:31:19 Paul Rubin wrote:
> Hendrik van Rooyen <hendrik at microcorp.co.za> writes:
> > Standard Python idiom:
> >
> > if key in d:
> > d[key] += value
> > else:
> > d[key] = value
>
> The issue is that uses two lookups. If that's ok, the more usual idiom is:
>
> d[key] = value + d.get(key, 0)
I was actually just needling Aahz a bit. The point I was trying to make
subliminally, was that there is a relative cost of double lookup for all
cases versus exceptions for some cases. - Depending on the frequency
of "some", I would expect a breakeven point.
- Hendrik
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