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gh-74690: Further optimise `typing._ProtocolMeta.__instancecheck__` by AlexWaygood · Pull Request #103280 · python/cpython · GitHub
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gh-74690: Further optimise typing._ProtocolMeta.__instancecheck__#103280

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AlexWaygood merged 1 commit into
python:mainfrom
AlexWaygood:more-optimisation
Apr 5, 2023
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gh-74690: Further optimise typing._ProtocolMeta.__instancecheck__#103280
AlexWaygood merged 1 commit into
python:mainfrom
AlexWaygood:more-optimisation

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AlexWaygood commented Apr 5, 2023 •
edited by bedevere-bot
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I probably should have spotted this when doing #103034! This provides some more speedup for isinstance() checks against runtime-checkable protocols. The improvement is small, but noticeable.

Benchmarks on main:

Time taken for objects with a property: 2.53 Time taken for objects with a classvar: 2.59 Time taken for objects with an instance var: 3.18 Time taken for objects with no var: 2.38 Time taken for nominal subclass instances: 0.19 Time taken for registered subclass instances: 0.46

Benchmarks with this PR:

Time taken for objects with a property: 2.49 Time taken for objects with a classvar: 2.49 Time taken for objects with an instance var: 3.06 Time taken for objects with no var: 2.36 Time taken for nominal subclass instances: 0.18 Time taken for registered subclass instances: 0.47
Benchmark script
import time from typing import Protocol, runtime_checkable @runtime_checkable class HasX(Protocol): x: int def foo(self): ... class Foo: @property def x(self) -> int: return 42 def foo(self): ... class Bar: x = 42 def foo(self): ... class Baz: def __init__(self): self.x = 42 def foo(self): ... class Egg: ... class Nominal(HasX): def __init__(self): self.x = 42 class Registered: ... HasX.register(Registered) num_instances = 500_000 foos = [Foo() for _ in range(num_instances)] bars = [Bar() for _ in range(num_instances)] bazzes = [Baz() for _ in range(num_instances)] basket = [Egg() for _ in range(num_instances)] nominals = [Nominal() for _ in range(num_instances)] registereds = [Registered() for _ in range(num_instances)] def bench(objs, title): start_time = time.perf_counter() for obj in objs: isinstance(obj, HasX) elapsed = time.perf_counter() - start_time print(f"{title}: {elapsed:.2f}") bench(foos, "Time taken for objects with a property") bench(bars, "Time taken for objects with a classvar") bench(bazzes, "Time taken for objects with an instance var") bench(basket, "Time taken for objects with no var") bench(nominals, "Time taken for nominal subclass instances") bench(registereds, "Time taken for registered subclass instances")

AlexWaygood added type-feature A feature request or enhancement performance Performance or resource usage stdlib Standard Library Python modules in the Lib/ directory topic-typing 3.12 only security fixes labels Apr 5, 2023
AlexWaygood requested a review from carljm April 5, 2023 15:00
bedevere-bot mentioned this pull request Apr 5, 2023
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AlexWaygood commented Apr 5, 2023 •
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Continuing to skip news for now until we've reached a decision on whether we want to consider more radical optimisations that would change behaviour (#74690 (comment)). Once I'm confident we've finished optimising this code, I'll add Whatsnew/Docs/NEWS entries for all of the optimisation PRs together :)

AlexWaygood merged commit de18267 into python:main Apr 5, 2023
AlexWaygood deleted the more-optimisation branch April 5, 2023 16:37

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AlexWaygood mentioned this pull request Apr 7, 2023
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gaogaotiantian pushed a commit to gaogaotiantian/cpython that referenced this pull request Apr 8, 2023
pythongh-74690: Further optimise `typing._ProtocolMeta.__instancechec… …
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…k__` (python#103280)
warsaw pushed a commit to warsaw/cpython that referenced this pull request Apr 11, 2023
pythongh-74690: Further optimise `typing._ProtocolMeta.__instancechec… …
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…k__` (python#103280)
AlexWaygood mentioned this pull request Apr 12, 2023
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AlexWaygood mentioned this pull request May 24, 2023
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AlexWaygood mentioned this pull request Aug 9, 2024
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carljm carljm approved these changes
gvanrossum Awaiting requested review from gvanrossum
Fidget-Spinner Awaiting requested review from Fidget-Spinner
JelleZijlstra Awaiting requested review from JelleZijlstra JelleZijlstra is a code owner

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