On 2013-01-25 23:14, Arnaud Delobelle wrote:
Dear Pythoneers,
I've got a seemingly simple problem, but for which I cannot find a
simple solution.
I have a set of objects (say S) containing an object which is equal to
a given object (say x). So
x in S
is true. So there is an object y in S which is equal to x. My
problem is how to retrieve y, without going through the whole set.
Here is a simple illustration with tuples (my actual scenario is not
with tuples but with a custom class):
y = (1, 2, 3) # This is the 'hidden object'
S = set([y] + range(10000))
x = (1, 2, 3)
x in S
True
x is y
False
You could first limit the search to only those which it could be:
S & set([y])
A search would be:
>>> f = [m for m in S & set([y]) if m is y][0]
>>> f is y
True
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