Peter Otten wrote:
Robert Bossy wrote:
I wish to know how two dict objects are compared. By browsing the
archives I gathered that the number of items are first compared, but if
the two dict objects have the same number of items, then the comparison
algorithm was not mentioned.
If I interpret the comments in
http://svn.python.org/view/python/trunk/Objects/dictobject.c?rev=64048&view=markup
correctly it's roughly
def characterize(d, e):
return min(((k, v) for k, v in d.iteritems() if k not in e or e[k] != v),
key=lambda (k, v): k)
def dict_compare(d, e):
result = cmp(len(d), len(e))
if result:
return result
try:
ka, va = characterize(d, e)
except ValueError:
return 0
kb, vb = characterize(e, d)
return cmp(ka, kb) or cmp(va, vb)
Thanks, Peter! That was exactly what I was looking for. Quite clever, I
might add.
RB
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