Here is a clear, simple, and exam-ready explanation of writing and executing your First Python Program. This includes all essential concepts needed for BCA/MCA/B.Tech students.
First Python Program
After installing Python successfully, you are ready to write your very first program.
Traditionally, the first program in any language prints the message:
Hello, World!
This tells us that Python is running properly.
1. Writing Your First Python Program
Step 1: Open a text editor or IDE
You may use:
- IDLE
- Notepad / Notepad++
- VS Code
- PyCharm
Step 2: Type the following code:
print("Hello, World!")
Step 3: Save the file with .py extension
Example:
hello.py
Step 4: Run the program
In Windows CMD:
python hello.py
In macOS/Linux Terminal:
python3 hello.py
Output:
Hello, World!
2. Understanding the First Program
Let’s break the program:
print("Hello, World!")
✔ print()
- It is a built-in function in Python.
- Used to display output on the screen.
✔ "Hello, World!"
- This is a string (text enclosed in quotes).
✔ No semicolon needed
Python does not require ; at the end of statements.
✔ Case-sensitive
print must be in lowercase; Print or PRINT will give an error.
3. Running Python Program in Interactive Mode
You can also run the same output directly in Python Shell.
Open the Python prompt:
>>>
Type:
>>> print("Hello, World!")
Output:
Hello, World!
4. Running Python Program in IDLE
- Open IDLE
- Click File → New File
- Write code:
print("Hello, Python!") - Save → test.py
- Press F5
Output will appear in the IDLE Shell.
5. Running Python Program in VS Code
- Open VS Code
- Install Python Extension (if not installed)
- Create file:
hello.py - Write code → Run
- Output appears in terminal
6. A Slightly Modified First Program
Let’s print multiple lines:
print("Welcome to Python Programming!")
print("This is your first program.")
Output:
Welcome to Python Programming!
This is your first program.
7. Comments in Python (Important for first program)
You can add comments to explain your program.
Single-line Comment
# This is my first Python program
print("Hello")
Multi-line Comment
"""
This is a multi-line comment.
It is ignored by Python.
"""
print("Hello")
8. Common Errors Beginners Make
| Mistake | Problem |
|---|---|
Print("Hello") | Wrong: Python is case-sensitive |
| Missing quotes | print(Hello) → Error |
| Wrong file extension | .txt instead of .py |
| Forgot to save before running | No output |
Summary
✔ Your first program uses print()
✔ Saves in .py file
✔ Runs using Python interpreter
✔ Output shown on screen
✔ Comments can be added for explanation