Home / Questions / 350905
Accepted
mauricio
Asked: 2020-04-30 19:42:50 +0800 CST 2020-04-30 19:42:50 +0800 CST

How can I reuse this method?

  • 772

I have a class that is inheriting from another:

class business2(business):
  steps()

The business class has a method from which I want to inherit all that procedure so as not to write the same thing again.

def steps(self):
    i = 0
    while i < self.quantityY:
        years = int(input("year :"))
        sales = int(input(str(years)
            +" sales value :"))
        #we create a list without discount
        self.allyears.append(years)
        self.witOdiscounts.append(sales)

        i+=1
        if i == self.quantityY:
            for x in self.witOdiscounts:
                print(x)

When I run I get this:

steps()
NameError: name 'steps' is not defined

The instance of course:

from exercise6 import *

instance = business2(2)
instance.steps()

What I want is to reuse that method to add more stuff to it and not have to copy and paste it.

python

1 Answers

  1. Best Answer

    If you are going to call the method manually like this:

    instance.steps()

    try the call in the child class with:

    class business2(business):
    steps()
    #^^^^^#

    surplus.

    When you inherit from the parent class, the method is simply inherited, it is exactly as if you had defined it in your child class and it is accessed identically:

    class Business:

    def steps(self):
        i = 0
        while i < self.quantityY:
            years = int(input("year :"))
            sales = int(input(str(years)
                +" sales value :"))
            #we create a list without discount
            self.allyears.append(years)
            self.witOdiscounts.append(sales)

            i+=1
            if i == self.quantityY:
                for x in self.witOdiscounts:
                    print(x)

class Business2(Business):
    pass

instance = Business2(2)
instance.steps()

    If you want to call them automatically when the class is instantiated you must do it from the initializer and use self.stepsto reference it:

    class Business2(Business):
    def __init__(self):
        super().__init__(self)
        self.steps()

instance = Business2(2)

    If you do this:

    class Business2(Business):
    self.steps()

    the method will be executed at definition time not when you instantiate the class.

    In case you want to override the method in your child class but you need the execution of the parent method to be carried out use superto call it:

    class Business2(Business):
    def steps(self):
        super().steps()
        print("Ahora estoy ejecutando la parte propia de la clase hija")

instance = Business2(2)
instance.steps()

    As a note, remember that by convention classes are always named using CamelCase to differentiate them from modules, functions, methods and variables that use lowercase and _as a word separator.

    • 1