Check instantiation of abstract classes [abstract]

Mypy generates an error if you try to instantiate an abstract baseclass (ABC). An abtract base class is a class with at least oneabstract method or attribute. (See also abc module documentation)

Sometimes a class is made accidentally abstract, often due to anunimplemented abstract method. In a case like this you need to providean implementation for the method to make the class concrete(non-abstract).

Example:

from abc import ABCMeta, abstractmethod
 
class Persistent(metaclass=ABCMeta):
    @abstractmethod
    def save(self) -> None: ...
 
class Thing(Persistent):
    def __init__(self) -> None:
        ...
 
    ...  # No "save" method
 
# Error: Cannot instantiate abstract class 'Thing' with abstract attribute 'save'  [abstract]
t = Thing()