> 
> **Possible Duplicate:**  
> 
> [Understanding Python decorators](https://stackoverflow.com/questions/739654/understanding-python-decorators) 
> 
> 
> 

I was reading a django app source code where I find this

```
@login_required
def activities(request = None,\
            project_id = 0,\
            task_id = 0,\
            ...

```

What does the line that start with @ mean?