What is Python Programming?
Python is a high-level, easy-to-read programming language used to create software, websites, mobile applications, games, artificial intelligence (AI), data analysis applications, and many other types of programs.
Why is Python Called Versatile?
Python is called versatile because it can be used for many different types of work. Instead of learning a different programming language for every task, you can use Python for a wide variety of applications.
- Web Development
- Artificial Intelligence (AI)
- Machine Learning
- Data Science
- Data Analysis
- Automation
- Game Development
- Desktop Applications
- Mobile App Development
- Cybersecurity
- Web Scraping
- Cloud Computing
- Internet of Things (IoT)
- Robotics
- Scientific Computing
- Software Development
- Networking
- Blockchain
- Image Processing
- Computer Vision
What is Computer Programming?
Computer programming is the process of writing instructions (called code) that tell a computer what to do and how to do it.
A computer cannot think or make decisions on its own. It only follows the instructions given by a programmer.
It is also called coding, programming, or software in everyday language.
Setting Up Python Development Environment
Setting up a Python development environment means installing and configuring the tools needed to write and run Python programs.
Examples of Python Development Environments
These tools are commonly called Integrated Development Environments (IDEs).
- Visual Studio Code (VS Code)
- PyCharm
- Google Colab (Colab)
- Jupyter Notebook
- IDLE
- Spyder
What is Google Colab?
Google Colab is a cloud-based Python development environment. It lets you write and run Python code directly in your web browser, so you do not need to install Python on your computer.
Python Comments
What are Comments?
Comments are notes written inside a Python program to explain the code. They are ignored by the Python interpreter, so they are not executed.
Purpose of Comments
Comments are used to:
- Explain what the code does.
- Make the code easier to read and understand.
- Help other programmers understand the program.
- Remind yourself why you wrote a particular piece of code.
Types of Comments
Python mainly has two types of comments:
1. Single-Line Comment
A single-line comment starts with the # symbol.
Syntax
# This is a single-line comment
Example
# Print a welcome message
print("Welcome")
2. Multi-Line Comment
Python does not have a special multi-line comment symbol. A common way is to use triple quotes (''' or ''') to write comments that span multiple lines.
Example
"""
This program
prints a welcome
message.
"""
print("Welcome")
Variables in Python
What is a Variable?
A variable is a named location in memory that is used to store data. The value stored in a variable can be used or changed during the execution of a program.
Python Variables Example
x = 55
y = 66.6
name = "Salman"
age = 28
is_student = True
print(x)
print(y)
print(name)
print(age)
print(is_student)
Output:
55
66.6
Salman
28
True
Rules for Naming Variables
Python has some rules for naming variables.
1. Variable names must start with a letter or an underscore (_).
✅ Correct
name = "Ali"
_age = 20
❌ Incorrect
2name = "Ali"
2. Variable names can contain letters, numbers, and underscores.
✅ Correct
student1 = "Ahmed"
total_marks = 450
❌ Incorrect
student-name = "Ahmed"
(- is not allowed.)
3. Variable names cannot contain spaces.
✅ Correct
first_name = "Ali"
❌ Incorrect
first name = "Ali"
4. Variable names are case-sensitive.
This means uppercase and lowercase letters are treated as different names.
name = "Ali"
Name = "Ahmed"
print(name)
print(Name)
Output:
Ali
Ahmed
name and Name are two different variables.
5. Do not use Python keywords as variable names.
❌ Incorrect
if = 10
class = 5
These words are reserved by Python.
Types of Variables in Python
In Python, variables are commonly classified based on the type of value they store.
1. Integer (int)
An integer stores whole numbers (without decimal points).
Example
age = 20
marks = 95
Explanation
20 and 95 are integers because they are whole numbers.
2. Float (float)
A float stores decimal numbers.
Example
height = 5.8
price = 99.99
Explanation
5.8 and 99.99 are floats because they contain decimal points.
3. String (str)
A string stores text. Text is written inside single (' ') or double (" ") quotes.
Example
name = "Ali"
city = 'Lahore'
Explanation
"Ali" and 'Lahore' are strings because they contain text.
4. Boolean (bool)
A boolean stores only two values:
- True
- False
Example
is_student = True
is_logged_in = False
Explanation
- True means Yes or Correct.
- False means No or Incorrect.
Real-Life Example
Imagine a student registration form.
name = "Ali"
age = 20
height = 5.8
is_student = True
Here:
- name → String
- age → Integer
- height → Float
- is_student → Boolean
✅ Correct
marks = 90
student = "Ali"
1. Input Operation
An input operation allows the user to enter data into a program.
In Python, the input() function is used to take input from the user.
Input an Integer (int)
Use int(input()) to take a whole number as input.
age = int(input("Enter your age: "))
print(age)
Sample Output:
Enter your age: 20
20
Input a Float (float)
Use float(input()) to take a decimal number as input.
height = float(input("Enter your height: "))
print(height)
Sample Output:
Enter your height: 5.8
5.8
Input a String (str)
Use str(input()) to take text as input.
name = str(input("Enter your name: "))
print(name)
Sample Output:
Enter your name: Ali
Ali
2. Output Operation
An output operation displays information to the user.
In Python, the print() function is used to display output.
Syntax
print(value)
Example
print("Hello, World!")
Output:
Hello, World!
Operators and Expressions in Python
What are Operators?
Operators are special symbols that perform operations on values or variables.
Example
a = 10
b = 5
print(a + b)
Output:
15
Here:
+is the operator.- It adds the values of
aandb.
Types of Operators
1. Arithmetic Operators
Arithmetic operators are used to perform mathematical calculations.
| Operator | Meaning | Example |
|---|---|---|
+ |
Addition | 10 + 5 = 15 |
- |
Subtraction | 10 - 5 = 5 |
* |
Multiplication | 10 * 5 = 50 |
/ |
Division | 10 / 5 = 2.0 |
% |
Modulus (Remainder) | 10 % 3 = 1 |
** |
Exponent (Power) | 2 ** 3 = 8 |
// |
Floor Division | 10 // 3 = 3 |
Python Arithmetic Operators Example
a = 10
b = 5
print("Addition:", a + b)
print("Subtraction:", a - b)
print("Multiplication:", a * b)
print("Division:", a / b)
print("Modulus:", a % 3)
print("Exponent:", 2 ** 3)
print("Floor Division:", 10 // 3)
Output:
Addition: 15
Subtraction: 5
Multiplication: 50
Division: 2.0
Modulus: 1
Exponent: 8
Floor Division: 3
2. Comparison (Relational) Operators
These operators compare two values and return True or False.
| Operator | Meaning | Example |
|---|---|---|
== |
Equal to | 5 == 5 → True |
!= |
Not equal to | 5 != 3 → True |
> |
Greater than | 10 > 5 → True |
< |
Less than | 5 < 10 → True |
>= |
Greater than or equal to | 10 >= 10 → True |
<= |
Less than or equal to | 5 <= 10 → True |
Python Comparison (Relational) Operators Example
a = 10
b = 5
print("Equal to:", a == b)
print("Not equal to:", a != b)
print("Greater than:", a > b)
print("Less than:", a < b)
print("Greater than or equal to:", a >= b)
print("Less than or equal to:", a <= b)
Output:
Equal to: False
Not equal to: True
Greater than: True
Less than: False
Greater than or equal to: True
Less than or equal to: False
3. Assignment Operators
These operators assign values to variables.
| Operator | Meaning | Example |
|---|---|---|
= |
Assign | x = 10 |
+= |
Add and assign | x += 5 |
-= |
Subtract and assign | x -= 5 |
*= |
Multiply and assign | x *= 2 |
/= |
Divide and assign | x /= 2 |
%= |
Modulus and assign | x %= 3 |
//= |
Floor divide and assign | x //= 2 |
**= |
Exponent and assign | x **= 2 |
Python Assignment Operators Example
x = 10
x += 5
print(x)
x = 10
x -= 5
print(x)
x = 10
x *= 2
print(x)
x = 10
x /= 2
print(x)
x = 10
x %= 3
print(x)
x = 10
x //= 3
print(x)
x = 5
x **= 2
print(x)
Output:
15
5
20
5.0
1
3
25
4. Logical Operators
Logical operators combine two or more conditions into a single expression and return True or False.
| Operator | Meaning |
|---|---|
and |
True if both conditions are True. |
or |
True if at least one condition is True. |
not |
Reverses the result. |
Python Logical Operators Example
x = 10
y = 5
print(x > 5 and y < 10)
print(x > 20 or y < 10)
print(not(x > 5))
Output:
True
True
False
Operator Precedence in Python
What is Operator Precedence?
Operator precedence is the order in which Python evaluates operators in an expression.
Simple Definition:
Operator precedence is the set of rules that determines which operation is performed first in an expression.
Operator Precedence Table
| Precedence | Operator | Description |
|---|---|---|
| 1 (Highest) | () |
Parentheses |
| 2 | ** |
Exponent |
| 3 | *, /, //, % |
Multiplication, Division, Floor Division, Modulus |
| 4 | +, - |
Addition, Subtraction |
| 5 | ==, !=, >, <, >=, <= |
Comparison Operators |
| 6 | not |
Logical NOT |
| 7 | and |
Logical AND |
| 8 (Lowest) | or |
Logical OR |
Multiple Choice Questions (MCQs) on Python Programming
not operator:Test Yourself: Interactive MCQs (Operating System)
Multiple Choice Questions (MCQs) on Python Programming
FAQs
Python Programming FAQs
Python is a high-level, easy-to-read programming language used to develop websites, software, mobile apps, games, AI applications, and many other types of programs.
Python is called versatile because it can be used for many different tasks such as web development, AI, data science, automation, game development, and more.
Computer programming is the process of writing instructions (code) that tell a computer what to do and how to perform specific tasks.
A Python development environment is a collection of tools used to write, edit, run, and test Python programs.
Popular Python IDEs include Visual Studio Code (VS Code), PyCharm, Google Colab, Jupyter Notebook, IDLE, and Spyder.
Google Colab is a cloud-based Python development environment that allows you to write and run Python code directly in a web browser without installing Python.
Comments are notes added to Python code to explain its purpose. They are ignored by the Python interpreter and are not executed.
A variable is a named memory location used to store data that can be used or changed during program execution.
The basic Python data types are Integer (int), Float (float), String (str), and Boolean (bool).
The input() function is used to receive data entered by the user during program execution.
The print() function is used to display output or information on the screen.
Operators are special symbols that perform operations on variables and values, such as addition, comparison, and logical operations.
Arithmetic operators perform mathematical calculations. Examples include +, -, *, /, %, **, and //.
Logical operators (and, or, not) are used to combine or reverse conditions and return True or False.
Operator precedence is the set of rules that determines the order in which Python evaluates operators in an expression.