"Carl Banks" <[EMAIL PROTECTED]> wrote:
> Howabout something like this (untested):
>
> class CmpProxy(object):
> def __init__(self,obj):
> self.obj = obj
> def __eq__(self,other):
> return (self.obj.att_a == other.obj.att_b
> and self.obj.att_b == other.obj.att_b)
> def __hash__(self):
> return hash((self.obj.att_a,self.obj.att_b))
>
> set_a = set(CmpProxy(x) for x in list_a)
> set_b = set(CmpProxy(y) for y in list_b)
> overlaps = [ z.obj for z in set_a.intersection(set.b) ]
Or more generally:
class Comparable(object):
def __init__(self, obj, key):
self.obj,self._key = obj,key
def __hash__(self):
return hash(self._key(self.obj))
def __eq__(self, other):
return self._key(self.obj) == self._key(other.obj)
if __name__ == '__main__':
some_list = ["hello", "world"]
another_list = ["HeLlO", "word"]
key = str.lower
some_set = set(Comparable(x,key) for x in some_list)
another_set = set(Comparable(x,key) for x in another_list)
print "overlaps:", [x.obj for x in some_set.intersection(another_set)]
print "unique_some:", [x.obj for x in some_set.difference(another_set)]
print "unique_another:", [x.obj for x in another_set.difference(some_set)]
George
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