# Running Python in the Browser with Pyodide Pyodide brings Python and the scientific stack to the browser via WebAssembly. ## Basic Setup ```html 


    


```

## Using Python Packages

```javascript
async function setupPyodide() {
    pyodide = await loadPyodide();

    // Load packages
    await pyodide.loadPackage(['numpy', 'pandas']);

    console.log('Pyodide and packages loaded');
}

// Use NumPy
const result = pyodide.runPython(`
    import numpy as np
    arr = np.array([1, 2, 3, 4, 5])
    arr.mean()
`);
console.log('Mean:', result);
```

## Accessing JavaScript from Python

```javascript
// Make JavaScript functions available to Python
pyodide.globals.set('jsAlert', (msg) => alert(msg));

pyodide.runPython(`
    # Call JavaScript function from Python
    jsAlert("Hello from Python!")
`);
```

## Available Packages

Pyodide includes many scientific packages:
- numpy, pandas, scipy, matplotlib
- scikit-learn, networkx
- And many more from PyPI

Check the [Pyodide package list](https://pyodide.org/en/stable/usage/packages-in-pyodide.html) for what's available.

## Performance Notes

- First load can take a few seconds (downloading WASM)
- Execution speed is close to native Python
- Some packages may not be fully compatible
- Browser-based, so no filesystem access by default