利用Python中自带Tkinter模块创建一个用户登录界面（GUI）

给你完整代码，可实现图示的业务功能。如果对你有帮助，请点采纳。

import tkinter as tk
from tkinter import messagebox
t = tk.Tk()
t.title("Register&Login")
t.geometry('300x200')
v1=tk.StringVar()
v2=tk.StringVar()
fr00 = tk.Frame(t, width=300, height=40)
fr0 = tk.Frame(fr00, width=100, height=40)
fr11 = tk.Frame(fr00, width=300, height=40)
fr1 = tk.Frame(fr00, width=300, height=40)
lb0 = tk.Label(fr0, text='Username:')
li0 = tk.Entry(fr0,textvariable=v1)
lb1 = tk.Label(fr0, text='Password:')
li1 = tk.Entry(fr0, textvariable=v2)
name=[]
pwd=[]
def register():    
    if v1.get()=='':
        messagebox.showinfo('提示','请输入用户名和密码')
    else:
        name.append(v1.get())
        pwd.append(v2.get())
        messagebox.showinfo('提示', '注册成功')
def login():
    if v1.get() == '':
        messagebox.showinfo('提示', '请输入用户名和密码')
    else:
        if v1.get() in name:
            ind = name.index(v1.get())
            if v2.get()==pwd[ind]:
                messagebox.showinfo('提示', '登录成功')
            else:
                messagebox.showinfo('提示', '密码错误')
        else:
            messagebox.showinfo('提示', '用户不存在')

bu0 = tk.Button(fr1, text='Login', width=10,fg='blue',font=('SimHei',12,'bold'),command=login)
bu1 = tk.Button(fr1, text='Register', width=10, fg='red',font=('SimHei', 12, 'bold'),command=register)
fr00.pack()
fr0.pack()
fr11.pack()
fr1.pack()
lb0.pack()
li0.pack()
fr1.pack()
lb1.pack()
li1.pack()
bu0.pack(side=tk.LEFT)
bu1.pack(side=tk.RIGHT)
t.mainloop()