human
Complete the below
def _reverse_ordering(ordering_tuple):

    ''''Given an order_by tuple such as `(\'-created\', \'uuid\')` reverse the
    ordering and return a new tuple, eg. `(\'created\', \'-uuid\')`.'
    '''
assistant
#Here is the Python code you requested.
    def invert(x):
        return (x[1:] if x.startswith(u'-') else (u'-' + x))
    return tuple([invert(item) for item in ordering_tuple])