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[Enum] Deprecate member.member access with removal in 3.14 #95077
Description
Activity
Those performance issues are no longer a problem
As somebody who hasn't been following
enumchanges very closely: why is this?Performance timings on my system:
The code
import time import enum class Color(enum.Enum): RED = "Red" BLUE = "Blue" GREEN = "Green" RED, BLUE, GREEN = Color class FastColor: RED = Color.RED BLUE = Color.BLUE GREEN = Color.GREEN def f(): for _ in range(10000000): Color.RED Color.BLUE Color.GREEN def g(): for _ in range(10000000): FastColor.RED FastColor.BLUE FastColor.GREEN def h(): for _ in range(10000000): RED BLUE GREEN import timeit print(round(timeit.timeit('f()', number=1, globals=globals()), 2), end=' ') print(round(timeit.timeit('g()', number=1, globals=globals()), 2), end=' ') print(round(timeit.timeit('h()', number=1, globals=globals()), 2), end=' \n\n')
version enum "fast" enum global enum 3.9 2.23 0.78 0.41 3.10 2.68 0.91 0.47 3.11 2.29 0.72 0.21 3.12 2.21 0.62 0.14 The 3.12 timings are with every enum member being accessed via the
enum.propertydescriptor (i.e. no enum members being stored directly in the enum class__dict__).Out of curiosity I ran the above code with
member.memberaccess, both with and without the deprecation warning:warning no warning 20.41 4.16 So updating code to be correct will keep performance to 3.11 levels (or better).
How are the timings for accessing
Color.RED.valueaffected?Those performance issues are no longer a problem
As somebody who hasn't been following
enumchanges very closely: why is this?I can only imagine it's due to the work you and others have done. I had already noticed this in the other issue when comparing 3.10/3.11/3.12, and I was able to get another slight boost by storing the member directly in the descriptor and avoiding a dict lookup.
How are the timings for accessing
Color.RED.valueaffected?Some improvement, but I don't think I can take any credit for that (and those timings are not affected by this issue).
version enum property simple python descriptor standard property 3.9 5.96 4.9 2.11 3.10 5.64 5.01 2.18 3.11 3.67 3.46 1.58 3.12 3.03 2.75 0.78 I can make
.nameand.valuenormal properties (when no member by the same name exists), but when I tried that they stopped being reported byinspectand so also stopped showing up inpydoc.- added a commit that references this issue
on Jul 25, 2022
Accessing one enum member from another was originally forbidden, but added later to improve performance (but still warned against in the docs). Those performance issues are no longer a problem, and it is now possible to have deprecation warnings in the code to aid in transitioning away from such usage.