▶️ Running Python Code

There are several ways to run Python code. Understanding them will make your learning journey smoother.

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Method 1: Running a Python File

This is the most common way to run Python programs.

Steps:

1. Create a file with a .py extension (e.g., my_program.py)
2. Write your Python code in the file
3. Open terminal/command prompt
4. Navigate to the file's directory
5. Run: python my_program.py

Example:

Create greet.py:

name = "World"
print(f"Hello, {name}!")

Run it:

python greet.py

Output:

Hello, World!

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Method 2: Python Interactive Mode (REPL)

REPL = Read-Evaluate-Print-Loop

Great for quick experiments and testing small pieces of code.

How to Start:

python

You'll see:

Python 3.x.x (...)
Type "help", "copyright", "credits" or "license" for more information.
>>>

Try It:

>>> 2 + 2
4
>>> print("Hello!")
Hello!
>>> name = "Python"
>>> f"I love {name}"
'I love Python'
>>> exit()  # To leave

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Method 3: Running Code in Your Editor

Most modern editors can run Python directly.

VS Code:

1. Open your .py file
2. Click the ▶️ (Play) button in the top-right
3. Or press Ctrl+F5 (Windows) / Cmd+F5 (Mac)

PyCharm:

1. Open your .py file
2. Right-click → "Run 'filename'"
3. Or press Shift+F10

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Method 4: Jupyter Notebooks

Interactive notebooks that mix code, output, and documentation.

Install:

pip install jupyter

Start:

jupyter notebook

This opens in your browser where you can create .ipynb files.

Great for: - Data science - Learning (see code + results together) - Experimentation

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Which Method Should You Use?

Situation	Recommended Method
Learning concepts	REPL or Jupyter
Writing real programs	Python files + Editor
Quick calculations	REPL
Sharing code	Python files
Data analysis	Jupyter Notebooks

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Common Commands Reference

# Run a Python file
python filename.py

# Start interactive mode
python

# Check Python version
python --version

# Install a package
pip install package_name

# List installed packages
pip list

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💡 Tips

1. Always save your file before running it
2. Use meaningful file names like calculator.py not test1.py
3. Don't name your files after Python modules (e.g., don't create random.py)
4. Read error messages — they usually tell you what's wrong

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✅ Next Step

Now that you know how to run Python code, learn how to use this repository effectively!