[issue21101] Extend the PyDict C API to handle cases where the hash value is known
Alex Gaynor
report at bugs.python.org
Fri Apr 4 22:31:19 CEST 2014
Alex Gaynor added the comment:
d[key] += 1 still does two dict lookups, and invokes the hash function twice:
>>> class X(object):
... def __hash__(self):
... print "hashed"
... return 0
... def __eq__(self, other):
... return True
...
>>> d = {X(): 0}
hashed
>>> d[X()]
hashed
0
>>> d[X()] = 3
hashed
>>> d[X()] += 1
hashed
hashed
----------
_______________________________________
Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue21101>
_______________________________________
More information about the Python-bugs-list
mailing list