python实现简单的抽奖小程序，抽奖的内容从文件里面读取

打开文件，读取文件的内容，随机抽出一个然后删掉已经抽出来的号码

import random
from random import choice
f = open('allnum.txt')
data = f.read()
a = data
b = a.strip('\n').split('\n')
print(b)
y = choice(b)
print(y)
lines = [l for l in open("allnum.txt", "r") if l.find(y, 0) != 0]
fd = open("allnum.txt", "w")
fd.writelines(lines)
fd.close()
f.close