I have a problem using docstrings with decorators. Given the following example:

```
def decorator(f):
    def _decorator():
        print 'decorator active'
        f()
    return _decorator

@decorator
def foo():
    '''the magic foo function'''
    print 'this is function foo'

help(foo)

```

Now the help doesn't show me the docstring of `foo` as expected, it shows:

```
Help on function _decorator in module __main__:

_decorator()

```

Without the decorator, the help is correct:

```
Help on function foo in module __main__:

foo()
    the magic foo function

```

I know, that the function `foo` is wrapped by the decorator, and so the function object is not the function `foo` any more. But what is a nice solution to get the docstring (and the help) as expected?