Function overloading
Overloading functions in Python classes allows you to override a method’s behavior based on its arguments. For example, the __setitem__ method takes two arguments, a key and a value. This method changes the value of a key to its corresponding value. This behavior violates the fundamental principle of commutativity. If you want to override a method, be sure to add the double-underscore prefix to the name of the attribute.
Overloading functions in Python classes has a couple of advantages. First, overloaded functions use the implementation with the most specific signature. So, for instance, if you want to find the area of a square, you would use the function area. You’d also use parameter a and b to find the area of a rectangle. If you use these two values, you can safely overload both methods. However, you shouldn’t overload functions with undefined behavior.
Inheritance
Inheritance in Python classes refers to the process of passing on a class’ attributes and methods from one child class to another. The child class is not required to re-implement these attributes and methods in order to extend its parent class. This type of inheritance promotes a more composable architecture.
However, inheritance as a design strategy has a drawback. Inheritance can result in the proliferation of classes. A classic example of this problem is the Python logging module. As developers have needed to send log messages to new destinations, the base logging class has gradually gained new subclasses.
There are two types of inheritance in Python. Single inheritance is the simplest type of inheritance, which means that a child class inherits from a single parent class. The child class is then given access to all the methods and data of the parent class.
Composition
Python has a powerful feature called class composition, which is a great way to create dynamic classes. You can create classes that contain a variety of Component instances. Then, you can use the ranges keyword to specify how many of each type there should be. However, you should remember that class composition is different from inheritance. Inheritance involves extending a parent class, while composition uses an instance of a base class.
Despite the fact that Python supports both methods, it is best to use composition if you need to model a relationship. The benefits of this feature include the ability to reuse a derived class for different situations. You can also implement multiple interfaces in a single class.
Instance variables
Python class instance variables are variables that are declared within a class rather than within any individual function. These variables are typically declared in a method called __init__, where they receive a single argument: the object being instantiated. In addition, they can also receive one or more arguments for initial values, which is where they differ from their counterparts in other programming languages.
A class can also contain attributes, which are values that are unique to the object. For example, you can use the ‘i’ attribute, which returns a string. This will return a single integer, or a function object, or a docstring, which returns a class description. The attributes are available only in instance objects, so you may want to use them in combination with other variables, such as methods, to make a more complex object.
__init__ method
The __init__ method of a Python class is used to initialize the variables of a class. Another method of the class prints the values of its variables. You can use this method to fix errors in your code. But, you should understand its usage. We’ll discuss it in the next section. In the meantime, let’s take a look at its basics.
__init__ method of a Python class is the method that defines the basic concept of a class. This method takes the same arguments as the class constructor. You can even change the order of calling the __init__ method. By default, the parent class constructor will be called first. Alternatively, you can call it after the body of the child class constructor.