Python Tutorials

Introduction

Python is a popular, high-level programming language known for its readable syntax and wide range of applications. It is used in web development, automation, data analysis, artificial intelligence, machine learning, and many other technical fields.

These Python Tutorials explain programming concepts step by step, from writing your first line of code to building practical applications. Each topic includes explanations and Python coding examples to help you practise what you learn.

Why learn Python?

• Its syntax is relatively easy for beginners to read.
• It supports procedural and object-oriented programming.
• It can automate repetitive tasks.
• It has libraries for data analysis, AI, and web development.
• It helps beginners develop logical thinking and problem-solving skills.

How does a Python program work?

1. Write Python instructions in a code editor.
2. Save the program with a .py extension.
3. Run the program using the Python interpreter.
4. Python executes the instructions and displays the output.
5. Review the result, correct errors, and practise again.

Python Installation and Development Setup

Before following Python Programming Tutorials, install Python and choose a code editor. You can use Visual Studio Code, PyCharm, or Python's built-in IDLE editor.

Tools you need

• Python interpreter to run Python programs.
• Visual Studio Code or another code editor.
• Terminal or command prompt to execute commands.
• A browser to access documentation and learning resources.

Step 1: Install Python

Download Python from the official website and follow the installation instructions for your operating system.

Download Python from Python.org

Step 2: Verify the installation

python --version

On some systems, use python3 --version instead. The command should display the installed Python version.

Step 3: Create your first Python file

Create a folder named python-practice. Inside it, create a file called hello.py.

print("Hello, Python!")

print("I am learning Python programming.")

Run the program from your terminal:

python hello.py

Expected output:

Hello, Python!
I am learning Python programming.

Practice task: Change the messages and run the program again. This is the first step in learning Python programming.

Python Basics Tutorial

This Python Basics Tutorial introduces the essential rules used when writing Python code. Start with simple instructions before moving to conditions, loops, and functions.

1. The print() function

The print() function displays text, numbers, and calculated results in the output.

print("Welcome to Python")
print(25)
print(10 + 5)

2. Python comments

Comments explain code to people reading it. Python ignores single-line comments that begin with #.

# Display a welcome message
print("Welcome!")

3. Python indentation

Indentation defines blocks of code in Python. Use consistent indentation, commonly four spaces, inside conditions, loops, functions, and classes.

if 10 > 5:
    print("10 is greater than 5")

Python Variables and Data Types

Variables store values that a program can use later. Python determines a variable's type from the value assigned to it.

Creating variables

student_name = "Arun"
age = 20
percentage = 85.5
is_enrolled = True

print(student_name)
print(age)
print(percentage)
print(is_enrolled)

Common Python data types

Check a variable's type

age = 20
print(type(age))

name = "Arun"
print(type(name))

Practice task: Create variables for your name, age, course, and whether you are a student. Print each value.

Python Operators

Operators perform calculations, compare values, and combine conditions. Understanding operators helps you write useful Python coding examples and solve everyday programming problems.

1. Arithmetic operators

a = 10
b = 3

print(a + b)   # Addition
print(a - b)   # Subtraction
print(a * b)   # Multiplication
print(a / b)   # Division
print(a // b)  # Floor division
print(a % b)   # Remainder
print(a ** b)  # Exponentiation

2. Comparison operators

Comparison operators compare two values and return True or False.

first_mark = 85
second_mark = 70

print(first_mark > second_mark)
print(first_mark == second_mark)
print(first_mark != second_mark)

3. Logical operators

age = 22
has_id = True

print(age >= 18 and has_id)
print(age < 18 or has_id)
print(not has_id)

4. Assignment operators

score = 10
score += 5
print(score)

score -= 2
print(score)

Practice task: Create a simple calculator that accepts two numbers and displays their sum, difference, product, and quotient.

Conditional Statements in Python

Conditional statements allow a program to make decisions. The code runs different instructions depending on whether a condition is true or false.

Using if, elif, and else

mark = 78

if mark >= 90:
    print("Grade A")
elif mark >= 75:
    print("Grade B")
elif mark >= 50:
    print("Grade C")
else:
    print("Needs improvement")

The program checks the conditions from top to bottom. When a condition is true, its block runs and the remaining branches are skipped.

Using conditions with user input

age = int(input("Enter your age: "))

if age >= 18:
    print("You are an adult.")
else:
    print("You are under 18.")

The input() function returns text, so int() converts the entered value to an integer. This example assumes the user enters a valid whole number.

Practice task: Write a program that checks whether a number is positive, negative, or zero.

Loops in Python

Loops repeat instructions. Use a for loop to iterate through a sequence or a while loop to repeat while a condition remains true.

1. For loop

for number in range(1, 6):
    print(number)

range(1, 6) produces the numbers 1 through 5. The ending value is excluded.

2. While loop

count = 1

while count <= 5:
    print(count)
    count += 1

3. Break and continue

for number in range(1, 6):
    if number == 3:
        continue

    print(number)

continue skips the current iteration. break stops the loop entirely.

Practice task: Print the multiplication table for a number entered by the user.

Python Lists, Tuples, Sets, and Dictionaries

Collections allow you to store and manage multiple values. Choose the collection type based on whether you need ordered items, unique values, or key-value pairs.

1. Lists

A list is ordered and can be changed after creation.

courses = ["Python", "Java", "PHP"]

courses.append("JavaScript")
print(courses)
print(courses[0])

2. Tuples

A tuple is ordered but cannot be changed after creation.

coordinates = (10, 20)
print(coordinates[0])

3. Sets

A set stores unique values and does not guarantee a fixed display order.

numbers = {1, 2, 2, 3, 4}
print(numbers)

4. Dictionaries

A dictionary stores values using keys.

student = {
    "name": "Arun",
    "course": "Python",
    "mark": 85
}

print(student["name"])
print(student["course"])

Practice task: Store five student names in a list and display them one by one. Then create a dictionary for one student's name, course, and mark.

Python Strings

A string represents text. Python provides methods to search, format, split, and transform string values.

Common string operations

message = "Learn Python Programming"

print(message.lower())
print(message.upper())
print(message.title())
print(message.replace("Python", "Web"))
print(message.split())

String formatting with f-strings

name = "Arun"
course = "Python"

print(f"{name} is learning {course}.")

F-strings make it easy to insert variables and expressions into text. They are useful when generating messages, reports, and formatted output.

Practice task: Ask the user for their name and display a welcome message using an f-string.

Python Functions

A function is a reusable block of code that performs a particular task. Functions help organise a program and reduce repeated instructions.

Create and call a function

def greet():
    print("Welcome to Python!")

greet()

Functions with parameters and return values

def add_numbers(a, b):
    return a + b

result = add_numbers(10, 5)
print(result)

Parameters provide input to a function, while return sends a result back to the code that called it.

Default parameters

def welcome(name="Student"):
    print(f"Hello, {name}!")

welcome()
welcome("Arun")

Practice task: Create a function that accepts a student's marks and returns whether the student has passed.

Python Modules and Packages

A module is a Python file containing reusable code. Packages organise related modules into a directory structure. Python also includes a standard library with useful tools.

Import a built-in module

import math

print(math.sqrt(25))
print(math.pi)

Import a specific function

from random import randint

number = randint(1, 10)
print(number)

Install a package

python -m pip install requests

Use a virtual environment for project-specific dependencies. It helps keep one project's packages separate from another's.

python -m venv .venv

Practice task: Use the math module to calculate the square root of a number.

File Handling in Python

File handling allows a program to read information from files and save results for later use. Python's with statement helps close files safely after use.

Write to a text file

with open("notes.txt", "w", encoding="utf-8") as file:
    file.write("I am learning Python.")
    file.write("\\nThis is my first file.")

Read from a text file

with open("notes.txt", "r", encoding="utf-8") as file:
    content = file.read()

print(content)

Common file modes include r for reading, w for writing, and a for appending. Writing with w replaces existing file contents.

Practice task: Create a program that saves a list of tasks to a text file and displays them when the program runs again.

Exception Handling in Python

Exceptions are errors that occur while a program is running. Handling expected errors helps prevent a program from stopping unexpectedly and makes error messages more useful.

Using try and except

try:
    number = int(input("Enter a number: "))
    print(100 / number)
except ValueError:
    print("Please enter a valid whole number.")
except ZeroDivisionError:
    print("You cannot divide by zero.")

Using finally

try:
    print("Processing started.")
finally:
    print("Processing finished.")

The finally block runs whether or not an exception occurs. Use specific exception types whenever possible so genuine programming errors are not hidden.

Practice task: Write a calculator that handles invalid input and division by zero.

Object-Oriented Programming in Python

Object-oriented programming (OOP) organises related data and behaviour into classes and objects. It is useful when building applications with multiple related entities.

Classes and objects

class Student:
    def __init__(self, name, course):
        self.name = name
        self.course = course

    def introduce(self):
        print(f"My name is {self.name}.")
        print(f"I am learning {self.course}.")

student = Student("Arun", "Python")
student.introduce()

A class defines the structure and behaviour of objects. The __init__() method initialises an object, and self refers to the current instance.

Inheritance

class Person:
    def __init__(self, name):
        self.name = name

class Student(Person):
    def display(self):
        print(f"Student name: {self.name}")

student = Student("Arun")
student.display()

Important OOP concepts include classes, objects, constructors, inheritance, encapsulation, and polymorphism.

Practice task: Create a BankAccount class with methods to deposit money, withdraw money, and display the balance.

Popular Python Libraries

Python libraries provide reusable tools for common tasks. Choose a library based on what you want your application to do.

Example: Generate a random number

import random

number = random.randint(1, 100)
print(f"Your number is {number}")

Learn the Python language fundamentals before trying many third-party libraries. Strong basics make library documentation easier to understand.

Python Coding Examples for Practice

These Python Coding Examples help beginners apply basic programming concepts to small problems. Try to write each program yourself before checking the solution.

Example 1: Add two numbers

first = 10
second = 20

total = first + second
print("Total:", total)

Example 2: Check even or odd

number = int(input("Enter a number: "))

if number % 2 == 0:
    print("Even number")
else:
    print("Odd number")

Example 3: Find the largest of three numbers

a = 15
b = 28
c = 12

largest = max(a, b, c)
print("Largest number:", largest)

Example 4: Calculate a factorial

number = 5
factorial = 1

for value in range(1, number + 1):
    factorial *= value

print("Factorial:", factorial)

Example 5: Count vowels in a word

word = "programming"
vowels = "aeiou"
count = 0

for character in word.lower():
    if character in vowels:
        count += 1

print("Number of vowels:", count)

Once these examples become easy, practise with lists, dictionaries, functions, and files. Gradually combine several concepts into one program.

Python Projects for Beginners

Building small applications helps you apply what you learn through Python Tutorials. Start with a simple project and add features as your programming skills improve.

1. Simple Calculator

Concepts: Input, operators, conditions, functions.

• Accept two numbers from the user.
• Allow addition, subtraction, multiplication, and division.
• Display the result clearly.
• Handle invalid choices and division by zero.

2. Number Guessing Game

Concepts: Loops, conditions, and the random module.

• Generate a random number.
• Ask the user to guess the number.
• Provide higher or lower hints.
• Count the number of attempts.

3. Student Marks Manager

Concepts: Lists, dictionaries, functions, and conditions.

• Store student names and marks.
• Calculate total and average marks.
• Display a student's result.
• Find the highest mark.

4. To-Do List Application

Concepts: Lists, loops, functions, and file handling.

• Add new tasks.
• Display existing tasks.
• Mark tasks as completed or remove them.
• Save tasks to a file so they remain available later.

5. Contact Book

Concepts: Dictionaries, functions, and file handling.

• Save names and contact details.
• Search for a contact.
• Update or remove a contact.
• Store the data in a file.

How to build your first Python project

1. Choose one small problem to solve.
2. Write down the features you need.
3. Break the problem into smaller functions.
4. Build one feature at a time.
5. Test normal inputs and incorrect inputs.
6. Improve the code and document how to run it.

Python Learning Roadmap

Follow this learning path to move from beginner concepts to practical Python development. Practise each stage before moving to more advanced topics.

Frequently Asked Questions About Python Tutorials