Python的用户登录接口编制以及实现流程图

# Author: Steven Zeng
'''
作业：编写登录接口
输入用户名密码
认证成功后显示欢迎信息
输错3次后锁定
'''
print("welcome to here")
f1=open('username.txt')
f2=open('password.txt')
f3=open('error.txt')#建立一个Demo记录输错3次密码的用户，并对其锁定
username_true=f1.readlines()#readlines读取方式返回的是逐行一个元素的列表
password_true=f2.readlines()
un_error=f3.readlines()
f1.close()
f2.close()
f3.close()
UK={}
#建立一个字典形式为用户名对密码
for i in range(len(username_true)):
    UK[str(username_true[i])]=str(password_true[i])#注：字典的键必须是不可变更型数据（常用整数和字符串）
# 而键值可以是数字也可以是字符串
#print(un_error)
#print(un_error.count(777+'\n')
#print(UK)
count=0
while count<3:
    username = input("Please, input your username:")
    password = input("Please, input your keywords")
    if un_error.count(str(username+&#39;\n&#39;))>=3:
        print("Out of trying, You are Locking!")
        break
    elif str(username+&#39;\n&#39;) in UK and str(password+&#39;\n&#39;)==UK.get(str(username+&#39;\n&#39;)):
        print("welcome to you, honorable customer!")
        break
    else:
        print(&#39;&#39;&#39;Invalid customer， please try again!
        And you have {count_left1} times left!&#39;&#39;&#39;.format(count_left1=2-count))
        f3=open(&#39;error.txt&#39;,&#39;a&#39;)#建立一个Demo记录输错3次密码的用户，并对其锁定
        f3.write(username+&#39;\n&#39;)
        f3.close()
    count += 1