from random import *
from tkinter import *

window = Tk()
window.geometry("300x200")

number = "123456789"
new_string = "qwertyuiopasdfghjklzxcvbnm"
up_string = new_string.upper()
passw = number+new_string+up_string
List = list(passw)
shuffle(List)

user_passw = ''.join([choice(List) for x in range(8)])

def hello():
    print(user_passw)
button = Button(window, text="Click me", command=hello)


label = Label(window)
label.config(text='Enter Text', font='Arial 25', fg='gray')
label.pack(padx=50, pady=20)

button = Button(window, text="Click me", command=hello)
button.config(text="Click me", bg='black', fg='red', font="Arial 15",width=20, height=5)

button.pack()
window.mainloop()