import string
import random

KEY_LEN = 20

def base_str():
    return string.ascii_letters + string.digits

def key_gen():
    keylist = [random.choice(base_str()) for i in range(KEY_LEN)]
    return ("".join(keylist))

with open('out.txt', 'w') as f:
    for i in range(10):
        if i != 0: f.write('\n')
        f.write(key_gen())