def get_number(s):
    """ Check that s is number
    
    If s is a number, first attempt to convert it to an int.
    If integer conversion fails, attempt to convert it to a float.
    If float conversion fails, return None.
    
    Inputs:
        s - An input string or number
    Outputs:
        value - Either float, int or None
    """
    try:
        return [int(si) for si in s.split('-')]
    except ValueError:
        try:
            return [float(si) for si in s.split('-')]
        except ValueError:
            return None