Le Wed, 09 Mar 2005 09:45:41 -0800, Dave Opstad a écrit :
> In this snippet:
>
> d = {'x': 1}
> value = d.get('x', bigscaryfunction())
>
> the bigscaryfunction is always called, even though 'x' is a valid key.
> Is there a "short-circuit" version of get that doesn't evaluate the
> second argument if the first is a valid key? For now I'll code around
> it, but this behavior surprised me a bit...
def scary():
print "scary called"
return 22
d = dict(x=1)
d.get('x', lambda *a : scary())
# print 1
d.get('z', (lambda *a : scary())())
scary called
22
First (wrong) version :
d.get('z', lambda *a : scary())
<function <lambda> at 0x40598e9c>
>
> Dave
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