classical.subclass module

Tools for creating subclasses

classical.subclass.argumented_subclass(cls: type, name: str, *args, **kwargs)

Create a subclass of cls identical to the original except for its name and additional arguments passed to __init__

Parameters

• cls – the class to be subclassed

• name – name of the new class

• args – positional arguments for __init__

• kwargs – keyword arguments for __init__

Returns

a subclass of cls

Say you have

class Square:
    def __init__(self, size, color=None):
        pass  # implementation goes here

The ‘standard’ way to subclass with fixed argument values would be to

class RedSquare1x1(Square):
    def __init__(self):
        super().__init__(1, color='red)

Consider the less-verbose alternative (kind of like the partial function, but for classes):

RedSquare1x1 = argumented_subclass(Square, 'RedSquare1x1', 1, color='red')

Note

Existence of __slots__ (and, consequently, the absence of the instance __dict__) is preserved during subclassing

classical.subclass.attributed_subclass(cls: type, name: str, **attributes)

Create a subclass of cls identical to the original, but with additional or redefined attributes

Parameters

• cls – the class to be subclassed

• name – name of the new class

• attributes – new attributes

Returns

a subclass of cls

class Animal:
    pass  # implementation goes here

Bird = attributed_subclass(Animal, 'Bird', wings=2)
pelican = Bird()  # pelican.wings == 2

Note

Existence of __slots__ (and, consequently, the absence of the instance __dict__) is preserved during subclassing