Calling Methods Within a Class

In object-oriented programming, classes are used to define custom data types and organize code into logical units. When working with classes, it’s common to have multiple methods that need to interact with each other. In this tutorial, we’ll explore how to call a method within a class from another method.

Understanding Class Methods

Class methods are functions defined inside a class that belong to the class itself. They can be used to perform operations on the class’s data or to provide additional functionality. When defining a class method, it’s essential to include the self parameter as the first argument. The self parameter refers to the instance of the class and is used to access variables and methods from the class.

Calling Methods Within a Class

To call a method within a class from another method, you need to use the self keyword followed by the method name. For example:

class MyClass:
    def method1(self):
        # code for method1
        pass

    def method2(self):
        self.method1()  # calling method1 from method2

In this example, method2 calls method1 using the self keyword.

Example Use Case

Suppose we have a class called Coordinates that calculates the distance between two points. We can define two methods: distToPoint to calculate the distance and isNear to check if a point is near another point.

class Coordinates:
    def distToPoint(self, p):
        # code to calculate distance using Pythagoras theorem
        pass

    def isNear(self, p):
        distance = self.distToPoint(p)
        if distance < 10:  # arbitrary threshold
            return True
        else:
            return False

In this example, isNear calls distToPoint to calculate the distance and then checks if it’s within a certain threshold.

Inheritance and Method Calling

When working with inheritance, you may need to call methods from a parent class. You can use the super() function to access methods from the parent class.

class Parent:
    def greet(self):
        print("Greetings from Parent!")

class Child(Parent):
    def greet(self):
        super().greet()  # calls Parent's greet method
        print("Greetings from Child!")

In this example, Child overrides the greet method and uses super() to call the parent class’s greet method.

Best Practices

When calling methods within a class or using inheritance, keep the following best practices in mind:

• Always use the self keyword when accessing instance variables or methods.
• Use super() to access methods from parent classes instead of hardcoding the class name.
• Keep your code organized and readable by using clear method names and comments.

By following these guidelines and understanding how to call methods within a class, you can write more effective and maintainable object-oriented code.