Flask Decorator to auto convert request arg to a method parameter

request_arg.py

def request_arg(arg_name, arg_type=str, arg_default=None):
    """
    decorator to auto convert arg or form fields to
    named method parameters with the correct type
    conversion

        @route('/something/<greeting>/')
        @request_arg('repeat', int, 1)
        def route_something(greeting='', repeat):
            return greeting * repeat

        # /something/yo/?repeat=10

        # yoyoyoyoyoyoyoyoyoyo

    :param arg_name str: name of the form field or arg
    :param arg_type lambda: (optional) the type to convert to
    :param arg_default any: (optional) a default value.  Use '' or 0 when allowing optional fields
    :return: a decorator
    """

    def decorator(f):
        @wraps(f)
        def decorated(*args, **kwargs):
            form_value = request.form.get(arg_name)
            arg_value = request.args.get(arg_name)
            if form_value:
                arg_value = form_value
            if not arg_value:
                arg_value = arg_default
            if arg_value is not None:
                try:
                    arg_value = arg_type(arg_value)
                except Exception as e:
                    abort(400, Response(f"""Required argument failed type conversion: {arg_name}, {str(e)}"""))

                kwargs[arg_name] = arg_value
                return f(*args, **kwargs)
            abort(400, Response(f"""Required argument missing: {arg_name}"""))

        return decorated

    return decorator