Introduction to Python
Learn Python Programming from Scratch | AKTU Tutorial
Introduction
Python is one of the most popular and powerful programming languages used today. It is a high-level, interpreted and general-purpose programming language that allows programmers to develop applications quickly with fewer lines of code.
Python was designed to be easy to read and easy to write. Unlike many other programming languages, Python uses simple English-like syntax, making it an excellent choice for beginners as well as professional software developers.
Today Python is used by millions of developers around the world in Artificial Intelligence, Machine Learning, Data Science, Web Development, Cyber Security, Automation, Scientific Computing, Cloud Computing and Desktop Application Development.
Because of its simplicity and huge collection of libraries, Python has become one of the most demanded programming languages in industries as well as universities.
Learning Objectives
After completing this tutorial, students will be able to:
- Understand what Python is.
- Know why Python is so popular.
- Identify the major features of Python.
- Understand where Python is used.
- Explain why Python is preferred over many other programming languages.
- Prepare for AKTU university examinations.
Prerequisite
No prior programming knowledge is required. Anyone having basic computer knowledge can easily start learning Python.
What is Python?
Python is a high-level, interpreted, object-oriented and general-purpose programming language developed by Guido van Rossum in 1991. It is designed to emphasize code readability and programmer productivity. Python programs are much shorter than programs written in many other languages, making development faster and easier.
Why is Python So Popular?
Easy Syntax
Python programs look similar to simple English statements.
Huge Library
Thousands of built-in modules help developers build applications quickly.
Cross Platform
Python programs can run on Windows, Linux and macOS.
Characteristics (Features) of Python
Python has become one of the world's most popular programming languages because it provides many useful features. These features make Python easy to learn, easy to use and suitable for developing different types of software applications.
| S.No. | Feature | Description |
|---|---|---|
| 1 | Simple | Python uses simple English-like syntax which is easy to understand. |
| 2 | Easy to Learn | Beginners can start programming with Python without having prior programming experience. |
| 3 | Interpreted | Python executes programs line by line without converting the entire program into machine code. |
| 4 | Object-Oriented | Python supports Object-Oriented Programming concepts like classes, objects, inheritance and polymorphism. |
| 5 | Portable | Python programs can run on Windows, Linux and macOS without major changes. |
| 6 | Open Source | Python is free to download, install and use. |
| 7 | Large Library | Python provides thousands of built-in modules and external libraries. |
| 8 | Extensible | Python can easily work with programs written in C and C++. |
Step-by-Step Understanding of Python
Let us understand Python with a simple example.
Other programming languages often require lengthy syntax, whereas Python allows developers to solve the same problem using fewer lines of code.
Real-Life Example of Python
Imagine a calculator. Whenever you press 5 + 10 = the calculator performs three tasks:
- Accepts the input.
- Processes the calculation.
- Displays the output.
Python programs work in exactly the same way.
| Step | Python Activity |
|---|---|
| Input | User enters data. |
| Processing | Python performs calculations. |
| Output | Result is displayed on the screen. |
Advantages of Python
- Simple and easy syntax.
- Easy to learn for beginners.
- Free and Open Source.
- Supports Object-Oriented Programming.
- Platform Independent.
- Large collection of built-in libraries.
- Fast application development.
- Less coding compared to many languages.
- Supports Artificial Intelligence and Machine Learning.
- Highly demanded in industries.
Limitations of Python
- Slower than compiled languages like C and C++.
- Consumes more memory.
- Not preferred for mobile application development.
- Not suitable for low-level system programming.
- Execution speed is slower because it is interpreted.
Where is Python Used?
Python is used in almost every field of Computer Science. Some major application areas are listed below.
🌐
Web Development🤖
Artificial Intelligence📊
Data Science🔐
Cyber Security⚙
Automation📱
Desktop Applications☁
Cloud Computing📈
Scientific ComputingHow Does Python Work?
Whenever we write a Python program, the Python Interpreter converts our Python statements into machine understandable instructions and executes them one statement at a time. Since Python is an interpreted language, there is no need to compile the entire program before execution.
The complete execution process of a Python program is shown below.
This simple execution process makes Python easy to learn and debug.
Working of Python Step-by-Step
| Step | Description |
|---|---|
| 1 | The programmer writes the Python source code (.py file). |
| 2 | The Python Interpreter reads the program line by line. |
| 3 | The Interpreter checks for syntax errors. |
| 4 | The instructions are converted into machine understandable form. |
| 5 | The program is executed. |
| 6 | The output is displayed on the screen. |
Python Interpreter
An Interpreter is a software program that reads, translates and executes Python code one line at a time. Unlike a compiler, an interpreter does not translate the complete program before execution.
Your First Python Program
The following program displays a simple message on the screen.
Python Program
print("Welcome to NoidaTut")
Output
Welcome to NoidaTut
Program Explanation
| Statement | Explanation |
|---|---|
| print() | print() is a built-in Python function used to display output on the screen. |
| "Welcome to NoidaTut" | This is a string (text) enclosed inside double quotation marks. |
| Semicolon (;) | Python does not require a semicolon at the end of every statement. |
Flow of Program Execution
Python vs C vs Java
| Feature | Python | C | Java |
|---|---|---|---|
| Learning Difficulty | Easy | Medium | Medium |
| Execution | Interpreted | Compiled | Compiled + JVM |
| Code Length | Very Short | Long | Long |
| Syntax | Simple | Complex | Moderate |
| Development Speed | Very Fast | Medium | Fast |
Common Mistakes Made by Beginners
- Using incorrect indentation.
- Forgetting quotation marks around strings.
- Using incorrect spelling of Python keywords.
- Mixing tabs and spaces.
- Using variables before declaring them.
- Ignoring error messages displayed by the interpreter.
Key Points to Remember
AKTU Important Questions
The following questions are frequently asked in AKTU semester examinations. Students should prepare these questions thoroughly.
Interview Questions
- What is Python?
- Who developed Python?
- Why is Python so popular?
- What are the advantages of Python?
- What is an Interpreter?
- Why is Python platform independent?
- Difference between Compiler and Interpreter?
- What is Python used for?
Viva Questions
- Who is the creator of Python?
- In which year was Python introduced?
- Is Python compiled or interpreted?
- What is the extension of Python files?
- Name any three Python applications.
- What is an Interpreter?
- Is Python case-sensitive?
- Can Python run on Linux?
- Is Python Open Source?
- Which company maintains Python?
Multiple Choice Questions (MCQs)
-
Python was developed by
- (A) Dennis Ritchie
- (B) James Gosling
- (C) Guido van Rossum ✔
- (D) Bjarne Stroustrup
-
Python is a ______ language.
- (A) Low Level
- (B) High Level ✔
- (C) Machine Level
- (D) Assembly Level
-
Python programs are executed using
- (A) Compiler
- (B) Interpreter ✔
- (C) Linker
- (D) Loader
-
Python file extension is
- (A) .java
- (B) .cpp
- (C) .py ✔
- (D) .exe
-
Python is
- (A) Proprietary
- (B) Open Source ✔
- (C) Closed Source
- (D) None of these
Practice Questions
- Define Python.
- Explain the characteristics of Python.
- Write advantages of Python.
- Write disadvantages of Python.
- Explain the working of Python Interpreter.
- Compare Python with C language.
- Write applications of Python.
- Explain why Python is easy to learn.
Quick Revision
Summary
In this tutorial, we learned the basic introduction to Python Programming, its features, advantages, disadvantages, applications, working of the Python Interpreter, and the execution of a simple Python program. We also discussed important AKTU questions, interview questions, viva questions and MCQs. In the next tutorial, we will study the History of Python and learn how Python evolved into one of the world's most popular programming languages.