gh-102213: Optimizing the Performance of __getattr__ #102213

[wangxiang-hz]

when __getattr__ is defined, python with try to find an attribute using _PyObject_GenericGetAttrWithDict. Find nothing is reasonable so we don't need an exception, it will hurt performance.

Using this test code:

import time
import sys

NUM = 1000000

class AttrObj(object):
    def __init__(self) -> None:
        super(AttrObj, self).__init__()
        self.pps = 2

    def __getattr__(self, name):
        return 4

def main():
    start = time.time()
    for i in range(1, NUM):
        pass
    end = time.time()
    peer = end - start
    o = AttrObj()
    print(f"Python version of {sys.version}")
    start = time.time()
    for i in range(1, NUM):
        s = o.ppp
    end = time.time()
    print(f"Call __getattr__ spend time: {end - start - peer}")

if __name__ == "__main__":
    main()

Now the result is: Call __getattr__ spend time: 0.4704132080078125
After this modification, the result is: Call __getattr__ spend time: 0.07422256469726562

• Issue: Improve the Efficiency of Python3.11.1 __getattr__ #102213

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[Fidget-Spinner]

Good work. Just a few things I think we should tidy up.

[wangxiang-hz]

Good work. Just a few things I think we should tidy up.

Thank you for your advice, it was very helpful. I also think that modifying the public C API could cause issues, but I was unsure whether to put the new function together with PyObject_GenericGetAttr. I think you're right.
I have updated my pull request, could you please take a look when you have time?
Thank you very much.

[Fidget-Spinner]

Also, thanks for addressing my review! In the future once you address the comments, you can just click "resolve conversation".

[Fidget-Spinner]

Thanks! Congrats on your first commit to CPython @wangxiang-hz !

[wangxiang-hz]

Also, thanks for addressing my review! In the future once you address the comments, you can just click "resolve conversation".

Thanks! Congrats on your first commit to CPython @wangxiang-hz !

Thank you! It's really my honor to participate in the development of CPython! Looking forward to make more pull requests in the future:)