from dataclasses import dataclass

import functools

import itertools

COUNT = itertools.count(1)

class Class:

@functools.cache

def count(self):

return next(COUNT)

class LruClass:

@functools.lru_cache(maxsize=None)

def count(self):

return next(COUNT)

@dataclass(frozen=True)

class CachedProperty:

def count(self):

return self._count

@functools.cached_property

def _count(self):

return next(COUNT)

def test_ok(cls):

a, b = cls(), cls()

print(f'ok: {a.count()=} {b.count()=}')

assert a.count() + 1 == b.count()

test_ok(Class)

test_ok(LruClass)

test_ok(CachedProperty)

@dataclass(frozen=True, eq=False)

class Cache:

@functools.cache

def count(self):

return next(COUNT)

@dataclass(frozen=True, eq=False)

class Lru:

@functools.lru_cache(maxsize=None)

def count(self):

return next(COUNT)

def test_fails(cls):

a, b = cls(), cls()

print(f'FAIL: {a.count()=} {b.count()=}')

assert a.count() == b.count()

test_fails(Cache)

test_fails(Lru)