from datetime import datetime


def x_values(dates):
    """
    Converts a list of date strings to datetime dates

    If multiplt lists are provided (via dict), the conversion will
    be applied to all lists and returned in a dictionary with the
    same keys as the input dictionary
    """
    if isinstance(dates,dict):
        return { k:x_values(v) for k,v in dates.items() }
    else:
        return [ datetime.strptime(d,"%m/%d/%y").date() for d in dates ]