Rick Sekuloski - PYTHON – Master Python OOP Programming with One Guide Only! A lot of Coding, Practice and Theory Learn Python with Hands-On Projects

Welcome to the first chapter. This chapter is by far the most important one. Here, the idea is to try to understand the basic Python features because without them you will have a hard time understanding the concepts in the following chapters where more intermediate features will be introduced. In this chapter, we will start by covering the basics of Python, like what Python is and how we can run Python code. Although it is called Python basics, there will be some features that are not that simple to understand, therefore, please make sure you spend enough time learning the concepts before moving to the next section.

What is Python?

According to official documentation, Python is An interpreted, object-oriented, high-level programming language with dynamic semantics. Python is a general computer programming language, meaning it can be used to create applications that will solve different problems. Python can be used to create websites, software, or to even perform data analysis. Learning Python is simple because it uses simple syntax, therefore, even people that are new to programming can learn it. Python emphasizes code readability and this can be achieved because Python supports modules and packages. In simple words, this means that instead of having one large file with thousands of lines of code, we can have multiple files that can communicate and share the code with the main file. This reduces the program maintenance cost and because Python is free to use, it is a perfect programming language. The Python programming language was created by Guido ban Rossum and it was first released on February 20, 1991.

Why is Python so popular?

Python is a widely used high-level programming language because the code is written in an English-like format or if you look at the code closely, you will see that is written similarly to the way humans think. Some may argue that Python is slower than other high-level languages like C , C++, or Java but this does not affect the end users. Another big advantage is that Python is more productive compared to Java and C++ because building an application takes less time, effort, and fewer lines of code. Because of its popularity, the Python community is exceptional and large. Having a large community is very important because Python allows us to create packages and modules that can be shared with the rest of the developers. This makes Python a flexible language with different real-world applications like:

• Games development
• Web Development
• AI and Machine learning
• E-commerce
• Image processing and graphic design
• Scientific computing

Another benefit is that the Python code is interpreted, not compiled. This means that the code is interpreted line by line during the runtime and doesnt require pre-runtime compilation. Because the Python code uses an Interpreter, it executes the statements line by line and its easier to debug and spot the errors. There are third-party tools that can be used to optimize the performance and to also to handle errors. One huge benefit is that Python code is portable and cross-platform functionality is a must in todays development. This means that applications created in Python can run on any operating system like Windows, macOS, Linus, and Unix without modifications. These are some of the features that make Python one of the most popular programming languages.

Python Interpreter

As we know from the definition, Python is an interpreted high - level language. This means Python needs an interpreter to read the code from our file and execute the instructions from that file. Other high-level languages like C++ require us to compile the code. The compilation process will turn the code that is humanly understandable into a code that only machines can understand called Machine code . The machine code consists of basic-level instructions that are executed by the CPU . After the compilation process, an executable file is generated. On the other hand, Python is an interpreted language, meaning it will not translate the code into machine code but will translate it into bytecode which will create a file with an extension (. pyc ). The Python interpreter comes when we install Python and we will see how this is done in chapter 3. This means when we install the official Python language, we have access to the Python interpreter as well. In short, the Python interpreter is a program that will read our source code and run it for us. So, what is the difference between the bytecode file and the compilation file ? Well, the compilation file is a set of instructions that are executed on the CPU and the bytecode file instructions are executed on a Virtual Machine known as CPython VM . Because of this (CPython VM), the bytecode can be executed on any operating system or platform. In simple words, a developer writes the code in Python and then the code is compiled into Python bytecode . This will create a file with an extension (. pyc ) and the bytecode is something that we as developers cant control because it happens in the background. So, the bytecode is a low-level representation of the code we write. The VM ( Python Virtual Machine ) is something we should not worry about as well because it is part of the Python system and is used to run our Python files/scripts. What is interesting is that the Python Interpreter is written and implemented as a C program and that is why its called CPython . Here is the figure that explains the whole process of how the Interpreter works: