python实现用户登录（验证码）

需求思路
用python编写
能实现登录 注册功能，其中包括用户名密码
实现验证码：
要求每一位验证码都有三种可能（大写字母，小写字母，数字）】
最后能退出

代码块

import tkinter as tk
import tkinter.messagebox
import pickle
import random
from PIL import ImageTk


def verifycode():
    # 验证码
    code_list = ''
    # 每一位验证码都有三种可能（大写字母，小写字母，数字）
    for i in range(6):  # 控制验证码生成的位数
        state = random.randint(1, 3)
        if state == 1:
            first_kind = random.randint(65, 90)  # 大写字母
            random_uppercase = chr(first_kind)
            code_list = code_list + random_uppercase

        elif state == 2:
            second_kinds = random.randint(97, 122)  # 小写字母
            random_lowercase = chr(second_kinds)
            code_list = code_list + random_lowercase
        elif state == 3:
            third_kinds = random.randint(0, 9)
            code_list = code_list + str(third_kinds)

    return code_list
# 验证码值
verification_Code = verifycode()

# 窗口
window = tk.Tk()
window.title('图书管理系统')
window.geometry('450x300')
# 设置登录窗口大小不可拉伸
window.resizable(width=False, height=False)
# 画布放置图片
canvas = tk.Canvas(window, height=300, width=500)
# imagefile = ImageTk.PhotoImage(file=r'.\背景图片.png')
imagefile = ImageTk.PhotoImage(file=r'.\背景.png')
image = canvas.create_image(0, 0, anchor='nw', image=imagefile)
canvas.pack(side='top')
# 标签 用户名密码
tk.Label(window, text='用户名:').place(x=100, y=110)
tk.Label(window, text='密   码:').place(x=100, y=150)
tk.Label(window, text='验证码:').place(x=100, y=190)
tk.Label(window, text=verification_Code).place(x=310, y=190)
# 用户名输入框
var_usr_name = tk.StringVar()
entry_usr_name = tk.Entry(window, textvariable=var_usr_name)
entry_usr_name.place(x=160, y=110)
# 密码输入框
var_usr_pwd = tk.StringVar()
entry_usr_pwd = tk.Entry(window, textvariable=var_usr_pwd, show='*')
entry_usr_pwd.place(x=160, y=150)
# 验证码输入框
var_usr_vercode = tk.StringVar()
var_usr_vercode = tk.Entry(window, textvariable=var_usr_vercode)
var_usr_vercode.place(x=160, y=190)

print(verification_Code)
# 登录函数
def usr_log_in():
    # 输入框获取用户名密码
    # 用户名
    usr_name = var_usr_name.get()
    # 密码
    usr_pwd = var_usr_pwd.get()
    # 验证码
    var_vercode = var_usr_vercode.get()
    # 从本地字典获取用户信息，如果没有则新建本地数据库
    try:
        with open('usr_info.pickle', 'rb') as usr_file:
            usrs_info = pickle.load(usr_file)
    except FileNotFoundError:
        with open('usr_info.pickle', 'wb') as usr_file:
            usrs_info = {'admin': 'admin'}
            pickle.dump(usrs_info, usr_file)
    # 判断用户名和密码是否匹配
    if usr_name in usrs_info:
        if usr_pwd == usrs_info[usr_name]:
            if var_vercode == verification_Code:

                tk.messagebox.showinfo(title='welcome',
                                       message='欢迎您：' + usr_name)
            else:
                tk.messagebox.showerror(message='验证码错误')
        else:
            tk.messagebox.showerror(message='密码错误')
    # 用户名密码不能为空
    elif usr_name == '' or usr_pwd == '':
        tk.messagebox.showerror(message='用户名或密码为空')

    # 不在数据库中弹出是否注册的框
    else:
        is_signup = tk.messagebox.askyesno('欢迎', '您还没有注册，是否现在注册')
        if is_signup:
            usr_sign_up()


# 注册函数
def usr_sign_up():
    # 确认注册时的相应函数
    def signtowcg():
        # 获取输入框内的内容
        nn = new_name.get()
        np = new_pwd.get()
        npf = new_pwd_confirm.get()

        # 本地加载已有用户信息,如果没有则已有用户信息为空
        try:
            with open('usr_info.pickle', 'rb') as usr_file:
                exist_usr_info = pickle.load(usr_file)
        except FileNotFoundError:
            exist_usr_info = {}

            # 检查用户名存在、密码为空、密码前后不一致
        if nn in exist_usr_info:
            tk.messagebox.showerror('错误', '用户名已存在')
        elif np == '' or nn == '':
            tk.messagebox.showerror('错误', '用户名或密码为空')
        elif np != npf:
            tk.messagebox.showerror('错误', '密码前后不一致')
        # 注册信息没有问题则将用户名密码写入数据库
        else:
            exist_usr_info[nn] = np
            with open('usr_info.pickle', 'wb') as usr_file:
                pickle.dump(exist_usr_info, usr_file)
            tk.messagebox.showinfo('欢迎', '注册成功')
            # 注册成功关闭注册框
            window_sign_up.destroy()

    # 新建注册界面
    window_sign_up = tk.Toplevel(window)
    window_sign_up.geometry('350x200')
    window_sign_up.title('注册')


    # 画布放置图片
    #canvas1 = tk.Canvas(window_sign_up)
    #imagefile1 = ImageTk.PhotoImage(file='.\背景.png')
    # imagefile = ImageTk.PhotoImage(file=r'.\背景图片.png')
    #image = canvas1.create_image(0, 0, anchor='nw', image=imagefile1)
    # canvas1.pack(side='top')

    # 用户名变量及标签、输入框
    new_name = tk.StringVar()
    tk.Label(window_sign_up, text='用户名：').place(x=10, y=10)
    tk.Entry(window_sign_up, textvariable=new_name).place(x=150, y=10)
    # 密码变量及标签、输入框
    new_pwd = tk.StringVar()
    tk.Label(window_sign_up, text='请输入密码：').place(x=10, y=50)
    tk.Entry(window_sign_up, textvariable=new_pwd, show='*').place(x=150, y=50)
    # 重复密码变量及标签、输入框
    new_pwd_confirm = tk.StringVar()
    tk.Label(window_sign_up, text='请再次输入密码：').place(x=10, y=90)
    tk.Entry(window_sign_up, textvariable=new_pwd_confirm, show='*').place(x=150, y=90)
    # 确认注册按钮及位置
    bt_confirm_sign_up = tk.Button(window_sign_up, text='确认注册',
                                   command=signtowcg)
    bt_confirm_sign_up.place(x=150, y=130)


# 退出的函数
def usr_sign_quit():
    window.destroy()


# 登录 注册按钮
bt_login = tk.Button(window, text='登录', command=usr_log_in)
bt_login.place(x=140, y=230)
bt_logup = tk.Button(window, text='注册', command=usr_sign_up)
bt_logup.place(x=210, y=230)
bt_logquit = tk.Button(window, text='退出', command=usr_sign_quit)
bt_logquit.place(x=280, y=230)
# 主循环
window.mainloop()