mypy-play

from dataclasses import dataclass

@dataclass
class Network:
    cidr: str

@dataclass
class Subnet:
    network: 'NetworkQ'
    cidr: str

mypy-play

from typing import TypeVar, Generator
from types import coroutine

T = TypeVar("T", str, bytes)

async def process(data: T) -> T:
    return data

@coroutine    
def process2(data: T) -> Generator[T, None, T]:

mypy-play

from typing import TypeVar, Generator
from types import coroutine

T = TypeVar("T", str, bytes)

async def process(data: T) -> T:
    return data

@coroutine    
def process2(data: T) -> Generator[T, None, T]:

mypy-play

def f(whatever) -> int:
    return 42
    
@f
class Foo: ...

reveal_type(Foo)

mypy-play

from typing import Pattern, Match
import re

reveal_type(re.compile("[abc]*"))
reveal_type(re.match(my_pattern, "abbcab"))

mypy-play

from typing import Pattern, Match
import re

reveal_type(re.compile("[abc]*"))
reveal_type(re.match(my_pattern, "abbcab"))

mypy-play

from pathlib import Path


class MyClass:
    def __init__(self, path: Path | None) -> None:
        self.path = path


def test(a: MyClass, b: MyClass):
    if a.path is None:

mypy-play

from typing import Callable, ParamSpec

P = ParamSpec('P')
DefaultP = ParamSpec('DefaultP', default=(int, str)) # Error

mypy-play

class A:
    import math

    def __new__(cls) -> "A":
        reveal_type(cls.math.pi)  # N: Revealed type is "Any"
        return cls()

    def pos_or_named_self(self) -> None:
        reveal_type(self.math.pi)  # N: Revealed type is "builtins.float"

mypy-play

class A:
    import math

    def __new__(cls) -> "A":
        reveal_type(cls.math.pi)  # N: Revealed type is "types.ModuleType"
        return cls()

    def pos_or_named_self(self) -> None:
        reveal_type(self.math.pi)  # N: Revealed type is "types.ModuleType"