Step counter

a = [1234, 4321]
b = [2345, 3214]

step = 0
for idx, _ in enumerate(a):
    x = [int(i) for i in str(a[idx])]
    y = [int(i) for i in str(b[idx])]
    for i, _ in enumerate(x):
        t1 = int(x[i])
        t2 = int(y[i])
        step += abs(t1-t2)
print(step)