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Ariel Montes
Asked: 2022-06-26 23:57:25 +0800 CST 2022-06-26 23:57:25 +0800 CST

How to execute an inherited method inside a class?

  • 772

As an example of what I am looking to achieve, I have created a Person class that inherits from Speech:

class Habla:
    def expresion(frase, grita):
        if grita:
            return frase.upper()
        else:
            return frase

class Persona(Habla):
    def __init__(self, frase, grita):
        self.grita = grita
        self.frase = super().expresion(frase, grita)

persona = Persona(frase="Aghh!", grita=True)

The problem I have is that I get an error when executing the method expresionof the class Speak.

I get the error:TypeError: expresion() takes 2 positional arguments but 3 were given

I suspect that the parameter selfis involved in the matter, but I don't know the cause.

I tried with the debug but I couldn't find when 3 parameters are passed to the method expresion.

Thanks in advance for any explanation you can give me. I emphasize that my goal is to be able to execute an inherited method inside a class and that I would like to know why I receive this error.

All the best.

python-3.x

2 Answers

  1. Best Answer

    I will respond only to the formal consultation.

    The code is wrong (does not compile). I corrected it the minimum to answer the question:

    class Habla:
    def expresion(self, frase, grita):
        if grita:
            return frase.upper()
        else:
            return frase

class Persona(Habla):
    def __init__(self, frase, grita):
        self.grita = grita
        self.frase = self.expresion(frase, grita)

a = Persona("hola", True)
print(a.frase)

    produces:

    HOLA

    Explanation

    The Person class descends from Speech, so it expresionbecomes its own method.

    A class's own methods are called using self:

    self.frase = self.expresion(frase, grita)

    recommended reading

    This question has too many concept and implementation issues. I recommend reviewing Inheritance in Python to see how this type of solution is correctly implemented.

    • 1

  2. Take the following code as an example and make it always receive "self".

    class Habla:
    def __init__(self):
        pass
    
    def expresion(self, frase, grita):
        if grita:
            return frase.isupper()
        else:
            return frase

class Persona(Habla):
    def __init__(self, _frase, _grita):
        self.grita = _grita
        self.frase = _frase
        super().expresion(self.frase, self.grita)

persona = Persona(_frase=“Aghh!”, _grita=True)
print(persona.grita, persona.frase)

    I hope it's worth it. It is important to "play" with self so that Python can reference your classes.

    Cheers!

    • 1