Find the closest integer in a list

find.py

def find_closest(t, vs):
    vs.sort()
    smallerest = None
    for v in vs:
        if not smallerest or (v < t and v > smallerest):
            smallerest = v

    vs.sort(reverse=True)
    biggerest = None
    for v in vs:
        if not biggerest or (v > t and v < biggerest):
            biggerest = v

    s_distance = None
    b_distance = None
    if smallerest:
        s_distance = t - smallerest

    if biggerest:
        b_distance = biggerest - t

    if s_distance is None and b_distance is None:
        raise RuntimeError()

    if s_distance and b_distance is None:
        return smallerest

    if s_distance is None and b_distance:
        return biggerest

    if b_distance < s_distance:
        return biggerest

    return smallerest

t = 7
vs = [1]

print find_closest(t, vs)