A password generator with GUI in python

gui_password_generator.py

import tkinter
import string
import random
class Window():

    MAX_CHARS = 15
    MIN_CHARS = 3
    CHARS_OPTIONS = ["Alphanumeric", 
                    "Numeric", 
                    "Alpha"]
    GRID_PADY = (18, 18)
    def __init__(self):
        self.initUI()
        
    
    def initUI(self):

        # Construction of the root element
        self.master = tkinter.Tk()
        self.master.title("Password Generator")
        self.master.geometry("580x250")
        
        
        self.ptype = tkinter.StringVar(self.master, 
                                    value=Window.CHARS_OPTIONS[0])
        self.n_chars = tkinter.IntVar(self.master, 
                                    value=Window.MIN_CHARS)
        
        self.label_chars = tkinter.Label(self.master, 
                text="Chars that will compose the Password: ")
        self.option_menu_chars = tkinter.OptionMenu(self.master, self.ptype ,*Window.CHARS_OPTIONS)
        
        

        self.frame_n_chars = tkinter.Frame(self.master) 
        self.label_num_chars = tkinter.Label(self.master, text="Password Length:")
        self.option_menu_n_chars = tkinter.OptionMenu(self.master, self.n_chars, *range(Window.MIN_CHARS, Window.MAX_CHARS+1))
        

        self.text_password_out = tkinter.Text(self.master, border=2, height=2, width=30)
        
        self.frame_buttons = tkinter.Frame()
        self.button_generate = tkinter.Button(self.frame_buttons, text="Generate", width=8, command=lambda: self.set_password())
        self.button_close = tkinter.Button(self.frame_buttons, text="Close", command=self.master.quit, width=8)

        self.label_chars.grid(row=0, column=0, pady=Window.GRID_PADY)
        self.option_menu_chars.grid(row=0, column=1)
        
        
        self.label_num_chars.grid(row=1, column=0, pady=Window.GRID_PADY)
        self.option_menu_n_chars.grid(row=1, column=1)
        

        self.text_password_out.grid(row=2, column=0, pady=Window.GRID_PADY)
        
        self.button_generate.pack(side=tkinter.LEFT)
        self.button_close.pack(side=tkinter.LEFT, pady=Window.GRID_PADY)
        self.frame_buttons.grid(row=3, column=1, columnspan=2)

        
               
        self.master.mainloop()

    def set_password(self):
        chars = ""
        ptype = self.ptype.get().lower()
        if ptype == "numeric":
            chars = string.digits

        elif ptype == "alpha":
            chars = string.ascii_letters
        else:
            chars = string.digits + string.ascii_letters   

        password = "".join(random.choices(chars, k=self.n_chars.get()))
        
        self.text_password_out.delete("1.0", tkinter.END)
        self.text_password_out.insert("1.0", password)
    
    
    


if __name__=="__main__":
    Window()