自动生成手机号-优化

import random

num=input('请输入你要生成的手机号个数:')
all_phone=[]
with open('phones.txt','a+') as f:
    count = 0
    while count<=int(num):
        start = '1891023'
        rand_num = str(random.randint(0, 9999))
        new_number = rand_num.zfill(4)
        phone_num = start + new_number
        if phone_num not in all_phone:
            all_phone.append(phone_num)
            count += 1
    for i in range(len(all_phone)):
        f.write(all_phone[i]+'\n')

优化生成手机号小程序：

1、.zfill是字符串类型的方法所以要把随机数转成字符串才可以使用该方法；随机数不够4位补0补够4位；

2、把列表的值通过循环写下标的方式写入；