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Author Talha Ahmed
Recipients Talha Ahmed
Date 2019-08-23.07:51:55
SpamBayes Score -1.0
Marked as misclassified Yes
Message-id <>
I have been experimenting a little with the `abc` module in python. A la

    >>> import abc

In the normal case you expect your ABC class to not be instantiated if it contains an unimplemented `abstractmethod`. You know like as follows:

    >>> class MyClass(metaclass=abc.ABCMeta):
    ...     @abc.abstractmethod
    ...     def mymethod(self):
    ...         return -1
    >>> MyClass()
    Traceback (most recent call last):
      File "<stdin>", line 1, in <module>
    TypeError: Can't instantiate abstract class MyClass with abstract methods mymethod

OR for any derived Class. It all seems to work fine until you inherit from something ... say `dict` or `list` as in the following: 

    >>> class YourClass(list, metaclass=abc.ABCMeta):
    ...     @abc.abstractmethod
    ...     def yourmethod(self):
    ...         return -1
    >>> YourClass()

This is inconsistent because `type` is supposed to be the primary factory.

    >>> type(abc.ABCMeta)
    <class 'type'>
    >>> type(list)
    <class 'type'>

Why is the check for `__abstractmethods__` only implemented for `object_new` and not for other built-in types?
Date User Action Args
2019-08-23 07:51:55Talha Ahmedsetrecipients: + Talha Ahmed
2019-08-23 07:51:55Talha Ahmedsetmessageid: <>
2019-08-23 07:51:55Talha Ahmedlinkissue37927 messages
2019-08-23 07:51:55Talha Ahmedcreate