How to correctly inherit arguments from parent to child class?-CodePudding

Is there a way to instantiate a child class that inherits all arguments from the parent class AND adds new arguments while:

keeping the argument order intact;
not requiring keyword arguments;
changing with the parent class?

Or is this an unconventional/unpythonic thing to do?

The following minimal-working example should explain my question more clearly.

Thanks in advance!

class Parent:
    '''
    Sample Parent class.
    
    Arguments
    ---------
    arg1: int
        Sample argument 1.
    arg2: int
        Sample argument 2.
    arg3: int
        Sample argument 3.
    '''
    def __init__(self, arg1, arg2, arg3):
        self.arg1 = arg1
        self.arg2 = arg2
        self.arg3 = arg3
        
        
class Child(Parent):
    '''
    Sample Child class.
    
    Arguments
    ---------
    arg1: int
        Sample argument 1.
    arg2: int
        Sample argument 2.
    arg3: int
        Sample argument 3.
    arg4: int
        Sample argument 4.
    '''
    # THIS CHANGES THE ORDER OF THE ARGUMENTS (arg4 is first.)
    def __init__(self, arg4, *args):
        super().__init__(*args)
        self.arg4 = arg4
    
    # THIS MAKES arg4 A KEYWORD-ONLY ARGUMENT.
    def __init__(self, *args, arg4):
        super().__init__(*args)
        self.arg4 = arg4
        
    # THIS REQUIRES MANUAL CHANGES IF THE PARENT CHANGES.
    def __init__(self, arg1, arg2, arg3, arg4):
        super().__init__(arg1, arg2, arg3)
        self.arg4 = arg4

CodePudding user response：

You could define the parent class to also use *args

def __init__(self, *args):
    self.arg1 = args[0]
    self.arg2 = args[1]
    self.arg3 = args[2]

And then the child:

def __init__(self, *args):
    super().__init__(*args)
    self.arg4 = args[-1]

This will pass all args to the parent but it would use only the first 3. The child will use only the last element in args