Metadata-Version: 2.1
Name: plain-abc
Version: 0.0.4
Summary: An ABC implementation without metaclass
Author-email: Chielo Newctle <ChieloNewctle@Yandex.com>
License: MIT License
        
        Copyright (c) 2023 Chielo
        
        Permission is hereby granted, free of charge, to any person obtaining a copy
        of this software and associated documentation files (the "Software"), to deal
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        IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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Project-URL: Homepage, https://github.com/ChieloNewctle/plain-abc
Project-URL: Bug Tracker, https://github.com/ChieloNewctle/plain-abc/issues
Classifier: Programming Language :: Python :: 3
Classifier: License :: OSI Approved :: MIT License
Classifier: Operating System :: OS Independent
Requires-Python: >=3.8
Description-Content-Type: text/markdown
License-File: LICENSE
Provides-Extra: tests
Requires-Dist: pytest ; extra == 'tests'

# plain-abc

An ABC implementation without metaclass.

It is a little bit annoying to have metaclass conflict,
especially when trying to use ABC along with other libraries.

`plain-abc` provides a simple ABC implementation without metaclass.

## Solving metaclass conflict without `plain-abc`

Here is an example of metaclass conflict
and a solution to mix ABCMeta and other metaclasses.

```python
from abc import ABC, ABCMeta, abstractmethod


class _SomeHiddenMetaclass(type):
    pass


class Base(metaclass=_SomeHiddenMetaclass):
    pass


class IFoo(ABC):
    @abstractmethod
    def foo(self): ...


# oh no, metaclass conflict!
# class Foo(Base, IFoo):
#     def foo(self): ...


# create a new metaclass for either IFoo or Foo
class NewMetaclass(_SomeHiddenMetaclass, ABCMeta):
    ...


class Foo(Base, IFoo, metaclass=NewMetaclass):
    def foo(self): ...
```

## Usage

But you can also use `plain-abc` to solve the problem:

```python
from abc import abstractmethod

from plain_abc import PlainABC


class _SomeHiddenMetaclass(type):
    pass


class Base(metaclass=_SomeHiddenMetaclass):
    pass


class IFoo(PlainABC):
    @abstractmethod
    def foo(self): ...


class Foo(Base, IFoo):
    def foo(self): ...
```

To extend an abstract class **as another abstract class**,
`PlainABC` is required to be one of the bases:

```python
from abc import abstractmethod

from plain_abc import PlainABC


class IEntity(PlainABC):
    @abstractmethod
    def get_id(self) -> str: ...


class IProjectile(IEntity, PlainABC):
    @abstractmethod
    def get_speed(self) -> float: ...


class Arrow(IProjectile):
    def get_id(self) -> str: ...
    def get_speed(self) -> float: ...
```

To skip signature checking,
you can add the member names in `__abc_concrete_members__` of a subclass:

```python
from abc import abstractmethod
from enum import Enum

from plain_abc import PlainABC


class IEnum(PlainABC):
    @property
    @abstractmethod
    def foo(self) -> str:
        ...


class Foo(IEnum, Enum):
    # for python 3.10 or lower
    __abc_concrete_members__ = ('foo',)
    foo = 'foo'


assert Foo.foo.value == 'foo'
```
