# Asynchronous File Downloader with Progress Bar  

This snippet demonstrates how to download files asynchronously in Python while displaying a progress bar. It uses `aiohttp` for asynchronous HTTP requests and `tqdm` for the progress bar visualization.  

```python
import aiohttp
import asyncio
from tqdm import tqdm

async def download_file(url, destination):
    async with aiohttp.ClientSession() as session:
        async with session.get(url) as response:
            if response.status != 200:
                raise Exception(f"Failed to download file: HTTP {response.status}")
            
            total_size = int(response.headers.get('content-length', 0))
            block_size = 1024  # 1 KB
            
            with open(destination, 'wb') as file, tqdm(
                total=total_size,
                unit='B',
                unit_scale=True,
                desc=f"Downloading {destination}"
            ) as progress_bar:
                async for chunk in response.content.iter_chunked(block_size):
                    file.write(chunk)
                    progress_bar.update(len(chunk))

async def main():
    url = "https://example.com/largefile.zip"
    destination = "largefile.zip"
    await download_file(url, destination)

if __name__ == "__main__":
    asyncio.run(main())
```

### Explanation  

#### **What It Does**  
- The script downloads a file from a given URL asynchronously, making it efficient for large files or multiple downloads.  
- It displays a progress bar using `tqdm`, showing the download progress in real-time.  
- The file is saved to the specified `destination` path.  

#### **Why It's Useful**  
- **Efficiency**: Uses `aiohttp` for non-blocking HTTP requests, improving performance.  
- **User Feedback**: The progress bar (`tqdm`) provides visual feedback, which is helpful for large downloads.  
- **Error Handling**: Checks HTTP status and raises an exception if the download fails.  

#### **How to Run**  
1. Install dependencies:  
   ```sh
   pip install aiohttp tqdm
   ```
2. Replace `url` and `destination` in the `main()` function with your desired file and output path.  
3. Run the script:  
   ```sh
   python downloader.py
   ```  

This snippet is ideal for scripts requiring efficient file downloads with a user-friendly progress indicator.