PCI 2-1

critics={'Lisa Rose': {'Superman Returns': 3.5, 'You, Me and Dupree': 2.5, 'The Night Listener': 3.0},
'Gene Seymour': {'Superman Returns': 5.0, 'The Night Listener': 3.5, 'You, Me and Dupree': 3.5}} 

def prepare_for_tanimoto(critics_arr):
    arr = critics_arr.copy()
    for critic in arr:
        for film in arr[critic]:
            if arr[critic][film] < 3:
                arr[critic][film] = 0
            else:
                arr[critic][film] = 1
    return arr


def tanimoto(critics_arr, critic1, critic2):
    arr = prepare_for_tanimoto(critics_arr)

    a = len(arr[critic1])
    b = len(arr[critic2])
    c = 0.0

    for film in arr[critic1]:
        if arr[critic1][film] == arr[critic2][film]:
            c = c + 1

    koef = c / (a + b - c)
    return koef

print tanimoto(critics, 'Gene Seymour', 'Lisa Rose')