自動生成用戶名和密碼

import random

user_sl=input('輸入隨機生成的條數')

username=[]

for i in range(int(user_sl)):
    kt='zhbr,123456'
    kt_str=kt.split(',')
    u=kt_str[0]
    p=kt_str[1]
    zj=str(random.randint(0,9999))
    a=zj.zfill(4)
    user=u+a
    if user not in username:
        username.append(user + ',' + p + '\n')
open('username.txt','w').writelines(username)