import string, random, time
start_time = time.time()
with open ('keys.txt', 'w') as fp:
    for _ in range(1000): fp.write('-'.join(''.join(random.choice(string.digits + string.ascii_uppercase) for _ in range(4)) for _ in range(4)) + '\n')
print("--- %s seconds ---" % (time.time() - start_time))