human
I wrote the below code

    def _use(expr, level):
        if (not level):
            return func(expr, *args, **kwargs)
        elif expr.is_Atom:
            return expr
        else:
            level -= 1
            _args = []
            for arg in expr.args:
                _args.append(_use(arg, level))
            return expr.__class__(*_args)
    return _use(sympify(expr), level)

What's a good function header?

=====
Here's a good function header?
assistant
#Here's a good function header.

def use(expr, func, level=0, args=(), kwargs={}):