[Python-Dev] Replacing self.__dict__ in __init__
INADA Naoki
songofacandy at gmail.com
Sun Mar 25 21:43:45 EDT 2018
>
> The dict can be replaced during __init__() and still get benefits of key-sharing. That benefit is lost only when the instance dict keys are modified downstream from __init__(). So, from a dict size point of view, your optimization is fine.
>
I think replacing __dict__ lose key-sharing.
Python 3.6.4 (default, Mar 9 2018, 23:15:03)
[GCC 4.2.1 Compatible Apple LLVM 9.0.0 (clang-900.0.39.2)] on darwin
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>>> class C:
... def __init__(self, a, b, c):
... self.a, self.b, self.c = a, b, c
...
>>> class D:
... def __init__(self, a, b, c):
... self.__dict__ = {'a':a, 'b':b, 'c':c}
...
>>> import sys
>>> sys.getsizeof(C(1,2,3).__dict__)
112
>>> sys.getsizeof(D(1,2,3).__dict__)
240
--
INADA Naoki <songofacandy at gmail.com>
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