【Python】随机生成校验码，保存于txt文件中

import random
import string
a=list(string.ascii_uppercase)
for i in range(1,10):
a.append(str(i))

def active_code(geshu,length):
for i in range(geshu):
k=''
for j in range(length):
k+=random.choice(a)
f=open("C:\Users\Administrator\Desktop\code.txt",'a')
f.write(k+' ')
f.flush()
f.close()