What is Python?

Python Mastery: From Beginner to Expert - Sykalo Eugene 2023

What is Python?
Introduction

Introduction

Python is an open-source, high-level, interpreted programming language that is easy to learn and use. It is a general-purpose language that can be used for a wide range of applications. Python has a simple syntax and is highly readable, making it a popular choice for beginners.

Some of the key features of Python include its simple and easy-to-learn syntax, interpreted language which means no compilation is required, object-oriented programming support, cross-platform compatibility, large standard library, and dynamic typing.

Python was first created by Guido van Rossum in 1989 while he was working at the National Research Institute for Mathematics and Computer Science in the Netherlands. The first public release of Python was in 1991.

Python 2 and Python 3 are two different versions of the Python programming language. Python 3 is the latest version of Python and is recommended for new development projects. However, there are still many projects that use Python 2, and it is important to be familiar with both versions.

Python is a versatile language that can be used for a wide range of applications, including web development, data science and machine learning, automation and scripting, game development, desktop applications, and network programming.

To get started with Python, you need to install Python on your computer. Python is available for Windows, Mac, and Linux. Once you have installed Python, you can use a text editor or an integrated development environment (IDE) to write Python code. There are several popular IDEs for Python, including PyCharm, Visual Studio Code, and Sublime Text.

Features of Python

Python has several features that make it a popular choice among developers. Some of the key features of Python include:

  • Simple and easy to learn syntax: Python has a simple and easy-to-learn syntax that makes it a popular choice for beginners. The syntax is designed to be readable, which makes it easier to understand and maintain code.
  • Interpreted language - no compilation required: Python is an interpreted language, which means that there is no need for compilation. This makes it easier to write and test code.
  • Object-oriented programming support: Python supports object-oriented programming (OOP), which allows developers to write reusable code and create complex applications.
  • Cross-platform compatibility: Python is a cross-platform language, which means that it can be used on different operating systems such as Windows, Mac, and Linux.
  • Large standard library: Python has a large standard library that provides a wide range of modules and functions that developers can use to build applications.
  • Dynamic typing: Python is a dynamically typed language, which means that the type of a variable is determined at runtime. This makes it easier to write code, but it can also lead to errors if variables are not used correctly.

History of Python

Python was created by Guido van Rossum in 1989 while he was working at the National Research Institute for Mathematics and Computer Science in the Netherlands. He was looking for a language that would be easy to learn and use, but that would also be powerful and flexible. He named the language after the British comedy group Monty Python.

The first public release of Python was in 1991, and the language quickly gained popularity among developers. In 2000, Python 2 was released, which introduced several new features and improvements. However, Python 2 was not fully backwards compatible with Python 1.x, which caused some compatibility issues.

In 2008, Python 3 was released, which addressed many of the issues with Python 2 and introduced several new features and improvements. Python 3 was not fully backwards compatible with Python 2, which caused some compatibility issues for developers who were using Python 2. However, Python 3 is now the recommended version of Python for new development projects, and many developers have migrated to Python 3.

Today, Python is one of the most popular programming languages in the world, and it is widely used in various fields such as web development, data science, machine learning, automation, and more. Python has a large and active community of developers who contribute to the language and its ecosystem of libraries and tools.

Python 2 vs. Python 3

Python 2 and Python 3 are two different versions of the Python programming language. Python 2 was released in 2000, and Python 3 was released in 2008. Although Python 3 is the latest version of Python, many developers still use Python 2. This is because there are many existing projects that were developed using Python 2, and it can be difficult to migrate these projects to Python 3.

There are several key differences between Python 2 and Python 3. One of the biggest differences is that Python 3 is not fully backwards compatible with Python 2. This means that code written for Python 2 may not work in Python 3 without modification. Some of the changes in Python 3 that can cause compatibility issues include:

  • Print statement: In Python 2, the print statement is used to print output to the console. In Python 3, the print statement was replaced with the print function, which requires parentheses around the output to be printed.
  • Division: In Python 2, the division operator (/) performs integer division if both operands are integers. In Python 3, the division operator always performs floating-point division, even if both operands are integers.
  • Unicode: In Python 2, strings are represented as ASCII by default. In Python 3, strings are represented as Unicode by default, which allows for better internationalization support.

Despite these differences, Python 3 offers several advantages over Python 2. One of the main advantages is that Python 3 is actively developed and maintained, while Python 2 is no longer receiving updates. This means that Python 3 is more secure and stable than Python 2.

Another advantage of Python 3 is that it includes several new features and improvements that are not available in Python 2. Some of these features include:

  • Improved Unicode support
  • Enhanced support for asynchronous programming
  • Simplified metaclass syntax
  • Improved exception handling

Applications of Python

Python is a versatile language that can be used for a wide range of applications. Some of the popular applications of Python include:

  • Web development: Python can be used to develop web applications using frameworks such as Django and Flask. These frameworks provide a high-level abstraction for web development, making it easy to develop web applications quickly and efficiently.
  • Data science and machine learning: Python is widely used in data science and machine learning due to its powerful libraries such as NumPy, Pandas, and Scikit-learn. These libraries provide tools for data analysis, manipulation, and visualization, as well as machine learning algorithms and models.
  • Automation and scripting: Python is a popular language for automation and scripting tasks due to its simple and easy-to-learn syntax. Python can be used to automate tasks such as file processing, data scraping, and web testing.
  • Game development: Python can be used to develop games using libraries such as Pygame and PyOpenGL. These libraries provide tools for game development, including graphics rendering, audio playback, and user input handling.
  • Desktop applications: Python can be used to develop desktop applications using frameworks such as PyQt and wxPython. These frameworks provide tools for building graphical user interfaces (GUIs) and interacting with the operating system.
  • Network programming: Python can be used to develop network applications using libraries such as Socket and Twisted. These libraries provide tools for building network servers and clients, as well as handling network protocols.

Getting Started with Python

To get started with Python, you need to install Python on your computer. Python is available for Windows, Mac, and Linux. You can download Python from the official Python website at https://www.python.org/downloads/.

Once you have installed Python, you can use a text editor or an integrated development environment (IDE) to write Python code. There are several popular IDEs for Python, including PyCharm, Visual Studio Code, and Sublime Text.

Writing Your First Python Program

To write your first Python program, open a text editor and enter the following code:

print("Hello, World!")

Save the file as hello.py and run it by opening a terminal or command prompt and entering the following command:

python hello.py

You should see the output Hello, World! printed to the console.

Basic Python Syntax

Python has a simple and easy-to-learn syntax that makes it a popular choice for beginners. Here are some basic Python syntax rules:

  • Python statements are executed line by line.
  • Statements that belong to the same block of code must have the same level of indentation.
  • Comments begin with the # symbol and are ignored by the Python interpreter.
  • Variables are created when a value is assigned to them.

Here is an example of Python code that demonstrates these syntax rules:

# This is a comment

x = 5
y = 10

if x < y:
 print("x is less than y")
else:
 print("x is greater than or equal to y")

Python Data Types

Python has several built-in data types that you can use to store and manipulate data. Here are some of the most commonly used data types:

  • Numbers: Integers and floating-point numbers.
  • Strings: Sequences of characters.
  • Lists: Ordered sequences of values.
  • Tuples: Immutable ordered sequences of values.
  • Dictionaries: Unordered collections of key-value pairs.
  • Sets: Unordered collections of unique values.

Here is an example of Python code that demonstrates these data types:

# Numbers

x = 5 # integer
y = 3.14  # floating-point number

# Strings

name = "John"
message = 'Hello, World!'

# Lists

fruits = ['apple', 'banana', 'cherry', 'orange']

# Tuples

coordinates = (10, 20)

# Dictionaries

person = {'name': 'John', 'age': 30, 'gender': 'male'}

# Sets

numbers = {1, 2, 3, 4, 5}

Python Functions

Functions are a way to group related code into reusable blocks. Python has several built-in functions, and you can also define your own functions. Here is an example of a Python function:

def greet(name):
 print("Hello, " + name + "!")

greet("John")

This code defines a function called greet that takes a parameter name and prints a greeting to the console. The function is then called with the argument "John", which results in the output Hello, John!.

Python Modules

Python modules are files that contain Python code. You can use modules to organize your code and make it reusable. Python has a large standard library that includes many useful modules, and you can also create your own modules. Here is an example of how to use a Python module:

import math

x = math.sqrt(25)

print(x) # Output: 5.0

This code imports the math module and uses it to calculate the square root of 25. The output is 5.0.