bench_classes.py

from collections import namedtuple
from dataclasses import dataclass
from typing import NamedTuple

import pyperf

@dataclass
class DataclassPet:
    legs: int
    noise: str


@dataclass(frozen=True)
class DataclassFrozenPet:
    legs: int
    noise: str

@dataclass(slots=True)
class DataclassSlotsPet:
    legs: int
    noise: str

CollectionsNamedTuplePet = namedtuple("Pet", "legs noise")

class ClassPet:
    legs: int
    noise: str
    def __init__(self, legs, noise) -> None:
        self.legs = legs
        self.noise = noise

    def __repr__(self):
        return f"<Pet legs={self.legs} noise='{self.noise}'>"

class TypingNamedTuplePet(NamedTuple):
    legs: int
    noise: str

if __name__ == '__main__':
    runner = pyperf.Runner()
    cases = [
        ('class',                   ClassPet),
        ('collections.namedtuple',  CollectionsNamedTuplePet),
        ('dataclass frozen',        DataclassFrozenPet),
        ('dataclass slots',         DataclassSlotsPet),
        ('dataclass',               DataclassPet),
        ('dict',                    dict),
        ('typing.NamedTuple',       TypingNamedTuplePet),
     ]
    for name, klass in cases:
        dog = klass(legs=4, noise="woof")
        runner.timeit(
            name=name,
            setup=f"dog = {klass.__name__}(legs=4, noise='woof')",
            stmt="str(dog)",
            globals={klass.__name__: klass},
        )

bench_classes2.diff

--- bench_classes.py       2022-03-02 22:05:47.000000000 +0000
+++ bench_classes2.py        2022-03-02 22:05:22.000000000 +0000
@@ -51,7 +51,6 @@
         dog = klass(legs=4, noise="woof")
         runner.timeit(
             name=name,
-            setup=f"dog = {klass.__name__}(legs=4, noise='woof')",
-            stmt="str(dog)",
+            stmt=f"dog = {klass.__name__}(legs=4, noise='woof'); str(dog)",
             globals={klass.__name__: klass},
         )

Replication of https://twitter.com/anthonypjshaw/status/1498913091492655111

$ python ../bench_classes.py
.....................
class: Mean +- std dev: 160 ns +- 2 ns
.....................
collections.namedtuple: Mean +- std dev: 229 ns +- 3 ns
.....................
dataclass frozen: Mean +- std dev: 430 ns +- 6 ns
.....................
dataclass slots: Mean +- std dev: 424 ns +- 5 ns
.....................
dataclass: Mean +- std dev: 430 ns +- 5 ns
.....................
dict: Mean +- std dev: 251 ns +- 2 ns
.....................
typing.NamedTuple: Mean +- std dev: 230 ns +- 5 ns

Python 3.10.2, on macOS 12.2.x, arm64

Including object initialisation

$ python ../bench_classes2.py
.....................
class: Mean +- std dev: 342 ns +- 3 ns
.....................
collections.namedtuple: Mean +- std dev: 411 ns +- 6 ns
.....................
dataclass frozen: Mean +- std dev: 753 ns +- 15 ns
.....................
dataclass slots: Mean +- std dev: 604 ns +- 14 ns
.....................
dataclass: Mean +- std dev: 640 ns +- 13 ns
.....................
dict: Mean +- std dev: 314 ns +- 3 ns
.....................
typing.NamedTuple: Mean +- std dev: 413 ns +- 8 ns