> ## 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.

# Project Handling

> Professional guidelines on structure, packages, imports, and environment isolation

Writing large-scale Python code requires clean structures, reusable packages, and isolated runtime environments. Let's cover how to handle and configure professional Python projects.

***

## 1. Modules and Packages

* **Module:** A single Python file (`.py`) containing code.
* **Package:** A directory containing multiple modules and a special file named `__init__.py`.

### Best Practices for Imports

* **Always use Absolute Imports:** Avoid relative imports (like `from ..utils import db`). These are prone to breaking when files are run as standalone scripts. Instead, use the project root path:
  ```python theme={null}
  from myproject.utils import db
  ```
* **Avoid `from module import *`:** Clutters your namespace and can overwrite existing functions or variables silently. Import explicitly:
  ```python theme={null}
  from math import sqrt, pi
  ```

***

## 2. Virtual Environments

A virtual environment is a local directory containing its own Python executable and installed dependencies.

### Why isolate environments?

By default, standard python installations share global libraries. If Project A needs `django 3.2` and Project B needs `django 4.2`, a global environment will crash. Virtual environments solve this by isolating packages per folder.

### Creating and Activating (Standard)

```bash theme={null}
# 1. Create environment
python -m venv .venv

# 2. Activate environment
# macOS / Linux:
source .venv/bin/activate

# Windows (PowerShell):
.venv\Scripts\Activate.ps1
```

### Modern Alternative: `uv`

**`uv`** is an ultra-fast Python package installer and resolver written in Rust by Astral, serving as a drop-in replacement for standard pip tools:

```bash theme={null}
# Create venv with uv (instant!)
uv venv

# Install packages
uv pip install requests
```

***

## What's next?

Now that you have completed Advanced Python, let's learn how to extend Python using standard libraries and external packages!

<Card title="Extending Python" icon="arrow-right" href="/libraries-apis/index">
  Learn standard library and external package management
</Card>