> ## Documentation Index
> Fetch the complete documentation index at: https://python4ai.codewithsiva.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# Interactive Python

> My favorite way to write Python code

## The best of both worlds

Interactive Python mode is my favorite way to write Python code, and I rarely use anything else. It combines the organization of Python files with the interactivity of Jupyter notebooks.

<Note>
  This is how I'll be coding throughout the entire course. Once you try it, you'll understand why it's so powerful for learning and developing AI applications.
</Note>

## What is Interactive Python?

Imagine you're cooking and tasting as you go, rather than waiting until the entire meal is done. That's Interactive Python:

* Write code in a `.py` file (organized and clean)
* Run pieces of it instantly with `Shift + Enter`
* See results immediately in a side panel
* Keep all your variables in memory

## Why it's perfect for AI development

When working with AI and data:

* You're constantly inspecting data
* Testing transformations
* Checking outputs
* Experimenting with different approaches

Running an entire file every time (like we did with `hello.py`) would be slow and frustrating. Interactive mode lets you work iteratively.

## Prerequisites

Interactive Python requires the IPython kernel. Let's install it:

1. Make sure your virtual environment is activated:
   ```bash theme={null}
   # You should see (venv) in your terminal
   ```

2. Install the required package:
   ```bash theme={null}
   pip install ipykernel
   ```

This package allows Jupyter to run Python code interactively.

## Set up Interactive Python

Now let's enable the interactive feature:

1. Open VS Code settings:
   * Press `Ctrl/Cmd + ,` (comma)
   * Or File > Preferences > Settings

2. Search for "execute selection"

3. Find this setting:
   **Jupyter > Interactive Window > Text Editor: Execute Selection**

4. Check the box to enable it

What this does: When you press `Shift + Enter`, your selected code will run in the Jupyter interactive window instead of the Python terminal. This gives you a much richer, more visual experience.

That's it! You're ready to use interactive mode.

## Your first interactive session

1. Create a new file called `interactive_demo.py`

2. Type this code:

```python theme={null}
# Let's explore interactive mode
name = "Python Learner"
print(f"Hello, {name}!")

# Some data to work with
numbers = [1, 2, 3, 4, 5]
print(f"Numbers: {numbers}")

# Calculate something
total = sum(numbers)
print(f"Total: {total}")
```

3. Place your cursor on the first line

4. Press `Shift + Enter`

Watch what happens:

* An Interactive window opens on the right
* Your code runs line by line
* You see output immediately

## Interactive superpowers

### Run selected code

* Highlight any code
* Press `Shift + Enter`
* Only that selection runs

### Variables stay in memory

Run this step by step:

```python theme={null}
# First, create a variable
message = "Hello"

# Later, use it (even in a different cell)
print(message + " World!")

# Modify it
message = message.upper()
print(message)
```

The variable `message` stays available throughout your session!

<Card title="Start learning Python" icon="rocket" href="/basics">
  Your environment is perfect. Let's dive into Python fundamentals!
</Card>