from tkinter import *

user_login = {
    'aaa': '123',
    'bbb': '654'
}

count = 0

def temp(s):
    win = Tk()
    win.geometry('100x100')

    message = Label(win, text=s)
    message.pack()

def login() :
    global count
    username = entry_username.get()
    if username not in user_login:
        label_message.config(text='账号错误')
    else:
        password = entry_password.get()
        if password == user_login[username]:
            #label_message.config(text='登录成功')
            temp('登录成功')

        else:
            label_message.config(text='密码错误！还可以尝试{}次'.format(2 - count))
            count += 1
            if count == 3:
                temp('登陆失败')
                btn_login.config(state='disabled')

windon = Tk()
windon.title('用户登录')
windon.geometry('300x200')

label_username = Label(windon, text='账号')
label_username.pack()

entry_username = Entry(windon)
entry_username.pack()

label_password = Label(windon, text='密码')
label_password.pack()

entry_password = Entry(windon, show='*')
entry_password.pack()

btn_login = Button(windon, text='登录', command=login)
btn_login.pack()

label_message = Label(windon, text="")
label_message.pack()

windon.mainloop()