Almost All Programmers And Training Sites Believe That Python Is A Simple Programming Language Because It Was Easy To Learn Its Syntax And Beginners Can Use The Concepts They Have Learned After A Few Months. 

Python, however, is best to read about important practical concepts that are highly convergent with other languages. In this article, we will mention some of these important concepts.

Concepts of object-oriented programming in Python

Object-Oriented Programming (OOP) The term Object-oriented programming refers to a specific type of computer programming in which the programmer defines the data type of a data structure and the types of operations (functions) that can be performed on the data structure. In this way, the data structure becomes an object that contains data and functions.

In addition, programmers can create relationships between one object and another. For example, objects can inherit properties from other objects.

One of the main advantages of object-oriented programming paradigms over procedural programming techniques is that they allow developers to use modules without changing modules when defining new objects.

A programmer can easily create a new object and inherit most of the properties of an existing object.

 This makes object-oriented programming easier.

Most modern programming languages ​​support the object-oriented paradigm, although some older programming languages, such as Pascal, offer a similar feature. High-level object-oriented programming languages ​​include Java, C ++, C #, Python, SmallTock, and more. The paradigm of object-oriented programming is surrounded by important concepts as follows:

Abstraction in Python

Abstraction refers to the process of picking common features of objects and procedures. This concept selects data from a large pool to show the user only the details of that object. Abstract only “shows” basic features and “hides” unnecessary information. Abstraction helps reduce complexity and improve programmer performance.

For this reason, one of the most important concepts of programming is objectivism. Hiding information means hiding the details of an object or function. Hiding information is a powerful programming technique because it reduces complexity.

Encapsulation in Python

Capsulation is the process of combining elements with building a new entity. A procedure is an encapsulation process because it combines a set of computer instructions. Encapsulation is one of the basic concepts of object-oriented programming (OOP). Encapsulation describes data and methods that operate as a single concept as a class.

This concept is also used to hide the interior view or the state of an object from the outside world. More precisely, only the information needed is shown to the outside world. The general idea of ​​this mechanism is simple.

If you have a trait that is not visible to the outside world of the object, and it is possible to provide this feature to the outside world with methods that make it possible to read or write to the object, you can hide specific information and the internal state of an object. Control.

Inheritance in Python

Inheritance is how one class acquires ownership, or more accurately, inherits from another class. For example, the child inherits the traits of his parents. Using inheritance, we can use fields and methods within a two-tier class. Thus, inheritance facilitates reusability and makes object-oriented programming more practical.

Types of inheritance

Single inheritance

Single inheritance allows a derived class to inherit traits and behavior from a parent class. In simpler terms, single inheritance allows a derived class to inherit the properties and behavior of a base class, thus allowing the code to be reused and new features added to the existing code. This allows us to have more accurate code and not have to write duplicate code.

In single inheritance, it extends to another class (only one class).

In the figure above, class B inherits the properties only from class A. Class A is a superclass, and Class B is a subclass.

Multiple Inheritance

Multiple inheritances are a feature of object-oriented programming languages ​​in which an object or class can inherit the properties and attributes of one or more parent objects.

In the figure above, class C inherits the properties of class A and class B.

Multilevel Inheritance

In multilevel inheritance, a class can inherit from a derived class. Hence, the derived class becomes the base class for the new class.

As you can see in the figure above, class C is subclass B, and B is subclass A.

Hierarchical Inheritance

This concept is called hierarchical inheritance, when more than one class inherits from the same class. In other words, several subclasses inherit from one class. In hierarchical inheritance, a parent class can have many children.

As you can see in the figure above, classes B, C, and D all inherit from class A.

Hybrid Inheritance

Combined inheritance is another type of inheritance. A class hierarchically inherits two or more classes, in which case classes can inherit from the same parent class in a hierarchical inheritance.

In hybrid inheritance, as shown in the figure above, all public and protected members of class A are inherited by class D through class B and then class C.

Determine the level of access

Determinants of access levels determine how members of a class are accessed. Typically, there are three determinants: Public, Private, and Protected.

Public

Members of a class that are publicly introduced are also available outside the classroom and can be used.

Private

Members of a privately defined class are available within that class but are not accessible outside of the class. By default, member variables and functions are defined privately.

Protected

Members of a class that are defined as protected have an approach similar to private access determinants. These variables are inaccessible from outside the class but can be accessed in subclasses.

Polymorphism

Polymorphism refers to the ability of an object to receive different types of shapes. The most common application of polymorphism in object-oriented programming occurs when the parent class reference refers to the child class object. Polymorphism can be static or dynamic. In static polymorphism, the response to a function is determined at compile time.

In dynamic polymorphism, the response to a function is determined at runtime. Therefore, polymorphisms are available in the following two ways:

1. Compilation time polymorphs (static)

2. Run time polymorphs (dynamic)

Compilation time polymorphs

Attaching a function to an object during compile time is called early binding. This condition is also known as static binding. There are two ways to implement static polymorphism.

1. Function overloading

2. Operator overloading

Function overload in Python

Function overload is a property in which two or more functions can have the same name but different parameters. Two or more functions with the same name but different arguments are known as function overloads. The following example shows an example of a functional overload called a test.

int test () {test

int test (int a) test test

float test (double a)}} int test (int a, double b) {}

In the example above, all 4 functions use the function overload approach because the arguments assigned to the functions are different.

Operator overload in Python

An operator in a programming language is a sublime that tells a compiler or interpreter to perform a specific mathematical, logical, or relational operation to obtain a definite result from that operation.

 For example, +, -, * and are mathematical operators and symbols such as &, | And! Logic operators and symbols such as>, <, =, etc., are relational operators. Operator overlay is a polymorphic type that defines different uses for the operator for the user.

 Operator overload is most often used when the user performs a series of calculations on self-defined data types. For example, the “+” operator can implement addition operations on various data types such as Integer or String.

Runtime polymorphs

Runtime or dynamic method Dispatch or delayed connection is when an overridden function is called instead of a compile-time at runtime. In this process, a transcribed method is called through a reference variable of a superclass. Determining the calling method is based on the object used by the reference variable.

Virtual Function

A virtual function is a member function defined in a base class and redefined by a derived class (Overriden). When you refer to a derived class object using a pointer or reference to the base class, you can call a virtual function for that object and execute the derived class function version.

Rules for a virtual function

Virtual functions must be part of a class.

Virtual functions cannot be static members.

•  They are accessible through object pointers.
• They can be friends or another class.
•  A virtual function must be defined in the base class, even if it is not used.

Prototypes of a virtual function of the base class and all derived classes must be the same.

• We can not have a virtual constructor, but we can have a virtual destroyer.

Classes in Python

Class is one of the most important concepts in the world of object-oriented programming. Classes are classified into user-defined data types and include their own functions and data types. Programmers can access the functions and data types of a class by creating an instance of a class.

Builders

Constructors are a special type of class object called by the compiler when an object instance is created. Constructors have the same name as the class and are defined inside or outside the class. Here are three types of manufacturers:

1. Default builder

2. The manufacturer has a parameter

3. Copy maker

Default constructors

A default constructor is a constructor that is called without any arguments.

Parameterized constructors

It is possible to send parameters to a manufacturer. Typically, these arguments are used to construct an object when constructing it. Building a constructor with parameters is enough to specify the parameters similar to defining functions for the constructor. You use these parameters to define an object when defining the body of the constructor.

Copy constructors

A constructor creates a new copy of an object that is an exact copy of an existing object. In this case, the compiler provides a default copy constructor for all classes. The constructor creates an object by initializing it with an object of the same class previously created. The copy maker is used in the following cases.»

Initialize one object by another object of the same type.

Copy an object to send it as an argument to a function

Copy an object to restore it from a function

If a class does not define a copy maker, the compiler itself defines it. If the class has pointer variables and dynamic memory allocation, there must be a copy maker. The most common forms of a copy maker are:

Classname (const classname * & obj) {// body of constructor

}

In the code snippet above, obj refers to an object used to initialize another object.

Destroyers

A destroyer is a class member’s function automatically called when an object is out of reach or explicitly destroyed to clear the object and free memory. Destroyer has the same name as the class, except that it has a prefix… For example, for the Destructor class, the function name of a destroyer is ru Destructor (). If it does not define a destroyer, the compiler will create it by default.

The above approach is sufficient for most classes. You only need to define a default destroyer if you have saved the system resource handle, and these resources need to be retrieved twice. This is also true for pointers that have their own memory.

Things

An object is an instance of a class containing methods and attributes used to construct a particular data type. When you send a message to an object, you ask the object to call or execute one of the methods defined in the class. From a programming point of view, an object can contain a data structure, a variable, or a function to which memory is allocated.

This object is created in the form of a class hierarchy. A class is a blueprint for building objects (a particular data structure), providing initial values ​​for a state (member variables or attributes), and implementing behavior (member functions or methods).