Python 3.2+deprecated in 3.3abcterm

abc.abstractclassmethod

abstract classes

Deprecated: an abstract classmethod. Use @classmethod on top of @abstractmethod.

Syntax

@abc.abstractclassmethod  # deprecated

This wrapper dates back to a time when classmethod could not propagate the abstractness flag; since Python 3.3 stacking @classmethod on top of @abstractmethod does the same job, and the separate decorator has been deprecated ever since. It survives in the standard library purely for old code — do not reach for it in anything new.

Examples

import abc
print(callable(abc.abstractclassmethod))            # → True
print(issubclass(abc.abstractclassmethod, classmethod))   # → True

import abc
class Base(abc.ABC):
    @abc.abstractclassmethod
    def create(cls): ...
print(Base.__abstractmethods__)                     # → frozenset({'create'})
class Modern(abc.ABC):
    @classmethod
    @abc.abstractmethod
    def create(cls): ...
print(Modern.__abstractmethods__)                   # → frozenset({'create'})
print(Base())                                       # → TypeError

See also

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