import random
import timeit

def is_private_ip(bits):
  return (bits[0] == 10 or
          bits[0] == 192 and bits[1] == 168 or
          bits[0] == 172 and 16 <= bits[1] < 32)

def gen_ip_1():
    while True:
        bits = [random.randrange(256) for _ in range(4)]
        if not is_private_ip(bits):
            break
    return '.'.join(map(str, bits))

b0_range = [i for i in range(256) if i != 10]
b1_172_range = [i for i in range(256) if not 16 <= i < 32]
b1_192_range = [i for i in range(256) if i != 168]
b_range = list(range(256))

def gen_ip_2():
    b0 = b0_range[random.randrange(0, len(b0_range), 1)]
    if b0 == 172:
        b1 = b1_172_range[random.randrange(0, len(b1_172_range), 1)]
    elif b0 == 192:
        b1 = b1_192_range[random.randrange(0, len(b1_192_range), 1)]
    else:
        b1 = b_range[random.randrange(0, len(b_range), 1)]
    b2 = b_range[random.randrange(0, len(b_range), 1)]
    b3 = b_range[random.randrange(0, len(b_range), 1)]
    return '.'.join(map(str, (b0, b1, b2, b3)))

def gen_ip_3():
    b0 = random.choice(b0_range)
    if b0 == 172:
        b1 = random.choice(b1_172_range)
    elif b0 == 192:
        b1 = random.choice(b1_192_range)
    else:
        b1 = random.choice(b_range)
    b2 = random.choice(b_range)
    b3 = random.choice(b_range)
    return '.'.join(map(str, (b0, b1, b2, b3)))

for f in gen_ip_1, gen_ip_2, gen_ip_3:
    print('{}: {}'.format(f.__name__, timeit.timeit(f)))