Random Trait String function

def rts(girl, options):
    """
    Get a random string from a random trait that a girl has.
    girl = The girl to check the traits against.
    options = A dictionary of trait/eval -> (strings,).
    """
    default = options.pop("default", None)
    available = list()

    for trait in options.iterkeys():
        if trait in traits:
            if trait in girl.traits: available.append(options[trait])

        else:
            if eval(trait, globals(), locals()): available.append(options[trait])

    if len(available) == 0: trait = default
    else: trait = choice(available)

    if isinstance(trait, (list, tuple)): return choice(trait)
    else: return trait