Returning to previous window not working in Python Tkinter -

i new python , trying had designing gui application.i have 3 classes in directory of python project, each 1 projects different window of different size therefore using window.destroy() everytime before call class, in 1 window, have button while trying access menu() function empty window loads up. below codes of 3 classes login, menu , customerdetails respectively. path being followed: login-->menu--> new customer--> button-->(ideal result=menu, result=blank window ).

from tkinter import * tkinter import ttk     frontend.menu import menu  class login:  def log(self):      if self.username.get() == "123" , self.password.get() == "123":         self.window.destroy()         menu()    def login(self):      # title frame     title=frame(self.window, border=2)     title.place(relx=0.5, rely=0.2, anchor=center)     # addng login form frame     frame=frame(self.window,background="#ccd5cc",     highlightthickness=2 )     frame.place(relx=0.5, rely=0.45, anchor=center)     # frame.pack()     # company label     company=label(title, text=" rajendra investments :: guwahati",background="#ccd5cc",                        font=("calibri", 18, "bold"))     # self.company.insert(insert," rajendra investments :: guwahati")     # self.company.configure(font=("calibri", 18, "bold"))     company.pack()     # adding heading label     headlabel1=ttk.label(frame,text="login credentials",background="#ccd5cc")     headlabel1.grid(row=0, column=0, pady=(10, 10), columnspan=2)     # username label     username=ttk.label(frame,text="username: ",background="#ccd5cc")     username.grid(row=1, column=0, pady=(10, 10), padx=(10,0))     # adding input field username     self.username = stringvar()     e1 = ttk.entry(frame, textvariable=self.username,background="#ccd5cc")     e1.grid(row=1, column=1,pady=(10, 10),padx=(0,10))     # password label     password=ttk.label(frame,text="password: ",background="#ccd5cc")     password.grid(row=2, column=0, pady=(10, 10), padx=(10,0))      # adding input field password     self.password = stringvar()     e1 = ttk.entry(frame, textvariable=self.password,background="#ccd5cc", show="*")     e1.grid(row=2, column=1,pady=(10, 10),padx=(0,10))     # button     b1 = ttk.button(frame, text="login", width=9, command=self.log)     b1.grid(row=3, column=0,columnspan=2, pady=(0, 10))  def __init__(self):      # creating window     self.window = tk()     self.window.title("finance maester")     self.window.minsize(width=500, height=450)     self.window.maxsize(width=500, height=450)     self.window.resizable(0,0)     background_image=photoimage(file="images/123.gif")     background_label = label( self.window, image=background_image)     background_label.pack()     self.login()     self.window.mainloop()    login() 

after login leads menu

from tkinter import * tkinter import ttk frontend.customerdetails import customerform  class menu:   def call_direct(self,key,value):     print(key, value)     if key=="new customer" , value=="1":         self.window.destroy()         customerform()     elif key=="old customer" , value=="3":         self.window.destroy()      elif key=="current customer" , value=="2":         self.window.destroy()       elif key=="search" , value.strip(" ")!="":         self.window.destroy()    def menu(self):       # frames     frame1=frame(self.window,background="#d5e1df")     frame1.place(relx=0.2, rely=0.25)     frame2=frame(self.window,background="#d5e1df")     frame2.place(relx=0.2, rely=0.35)     # search label     search=ttk.label(frame1, text="search: ",background="#d5e1df")     search.grid(row=0, column=0,pady=(10, 10), padx=(0, 10))     # # adding input field search     search = stringvar()     e1 = ttk.entry(frame1, textvariable=search, background="#ccd5cc", width=27)     e1.grid(row=0, column=1, padx=(0, 10))     # search button     sb = ttk.button(frame1, text="go", width=15,command=lambda : self.call_direct("search", search.get()))     sb.grid(row=0, column=2, padx=(0, 10),)     # menu button 1     mb1=ttk.button(frame2, text=" new customer ", command=lambda : self.call_direct("new customer","1"))     mb1.grid(row=0, column=0, padx=(0, 10), pady=(10,0))     # menu button 2     mb2=ttk.button(frame2, text=" current customer ", command=lambda : self.call_direct("current customer","2"))     mb2.grid(row=0, column=1, padx=(9, 10), pady=(10,0))     # menu button 3     mb3=ttk.button(frame2, text=" old customer ", command=lambda : self.call_direct("old customer","3"))     mb3.grid(row=0, column=2, padx=(10, 10), pady=(10,0))   def __init__(self):     # creating window     self.window = tk()     self.window.title("finance maester")     self.window.minsize(width=500, height=450)     # self.window.maxsize(width=self.window.winfo_screenwidth(), height=self.window.winfo_screenheight())     # self.window.resizable(0,0)     self.window.configure(background="#d5e1df")     # self.window.attributes("-toolwindow"=> 1)     # self.background_image=photoimage(file="images/123.gif")     # self.background_label = label( self.window, image=self.background_image)     # self.background_label.pack()     label=label(self.window,text="rajendra investments :: guwahati",font=('calibri',12,"bold"),background="#d5e1df")     # self.label.place(relx=0.05, rely=0.01)     label.pack(side="top", anchor="w", padx=(50, 0), pady=(10, 0))     self.menu()     self.window.mainloop() 

new customer form

from tkinter import * tkinter import ttk frontend.menu import menu frontend.installmentdetails import installmentdetails  class customerform():  def redirect(self, value):     self.window.destroy()     if value=="back":         menu()     elif value=="continue":         installmentdetails()   def custform(self):      # frames     frame1=frame(self.window,background="#d5e1df")     frame1.pack(side="left", anchor="nw", padx=(50, 0), pady=(50, 0))     frame2=frame(self.window,background="#d5e1df")     frame2.pack(side="left", anchor="ne",pady=(50, 0), padx=(0,50))      # frame1 blocks starts here     # block 1 starts here     statement_file_no=ttk.label(frame1,background="#d5e1df",text="statement file number : ", )     statement_file_no.grid(row=0, column=0, padx=(10, 10), pady=(10, 10), sticky="w" )      stfileno=stringvar()     statement_file_no_entry=ttk.entry(frame1, textvariable=stfileno, width=25)     statement_file_no_entry.grid(row=0, column=1, padx=(10, 10), pady=(10, 10), sticky="w")      date=ttk.label(frame1,background="#d5e1df", text="date : ")     date.grid(row=0, column=2 , padx=(10, 10), pady=(10, 10), sticky="e")      datetext=stringvar()     date_entry=ttk.entry(frame1, textvariable=datetext, width=22)     date_entry.grid(row=0, column=3, padx=(10, 10), pady=(10, 10), sticky="w")      hirer_name=ttk.label(frame1,background="#d5e1df",text="hirer name : ")     hirer_name.grid(row=1, column=0 , padx=(10, 10), pady=(10, 10), sticky="w")      hname=stringvar()     hirer_name_entry=ttk.entry(frame1, textvariable=hname, width=73)     hirer_name_entry.grid(row=1, column=1, columnspan=3, padx=(10, 10), pady=(10, 10), sticky="w" )      address=ttk.label(frame1,background="#d5e1df", text="address : ")     address.grid(row=2, column=0, padx=(10, 10), pady=(10, 10), sticky="w")      address=stringvar()     address_text=text(frame1,  height=2, width=55)     address_text.grid(row=2, column=1, columnspan=3, padx=(10, 10), pady=(10, 10), sticky="w")      # block 1 ends here       # button     sb = button(frame2, text=" back", width=20, font=("calibri", 12),command=lambda: self.redirect("back"))     sb.grid(row=9, column=0, columnspan=3, padx=(10, 30), pady=(20, 15), rowspan=2)      # submit button     sb = button(frame2, text=" continue",  width=20, font=("calibri", 12),command=lambda: self.redirect("continue"))     sb.grid(row=9, column=1,columnspan=3, padx=(10, 10), pady=(20, 15), sticky="e")  def __init__(self):     # creating window     self.window = tk()     self.window.title("finance maester")     # self.window.minsize(width=500, height=450)     # self.window.maxsize(width=500, height=450)     # self.window.resizable(0, 0)     w, h = self.window.winfo_screenwidth(), self.window.winfo_screenheight()     self.window.geometry("%dx%d+0+0" % (w, h))     self.window.configure(background="#d5e1df")     # self.window.attributes("-toolwindow"=> 1)     # self.background_image=photoimage(file="images/123.gif")     # self.background_label = label( self.window, image=self.background_image)     # self.background_label.pack(anchor="center")     self.label = label(self.window, text="rajendra investments :: guwahati", font=('calibri', 12, "bold"),                        background="#d5e1df")     # self.label.place(relx=0.05, rely=0.01)     self.label.pack(side="top", anchor="w", padx=(50,0), pady=(10,0))     self.custform()     self.window.mainloop() 

in class customer when try call menu if button pressed, empty window. have no idea why.