Remove previous WIDGETS on selecting options from Menubar in TKINTER - python-3.x

Question

I have a menu bar which has 2 options
[1]TO ADD DATA
[2]TO UPDATE THE DATA
When I select an option the widgets load in the window. When I select the other option after that , the previous widgets stay & new widgets overlapped. How do I keep the window & destroy the existing widgets over it.
I have not attached the original code with other menu options due to its size, however the code snippet replicates the actual scenario.
I have tried destroy() exit() & calling the function again
from tkinter import *
root = None
data = None
def _add(dt):
global data
data = dt
print(data, 'ADDED')
def _edit(new_dt):
global data
data = new_dt
print('UPDATED')
print("DATA =", data)
def cust_add():
global root
global data
lbl = Label(root,text="ADD NAME:")
ent = Entry(root)
btn = Button(root, text='ADD', command=lambda: _add(ent.get()))
lbl.pack()
ent.pack()
btn.pack()
def cust_edit():
global root
global data
lbl = Label(root, text="UPDATE NAME:")
ent = Entry(root)
btn = Button(root, text="UPDATE", command=lambda: _edit(ent.get()))
lbl.pack()
ent.pack()
btn.pack()
def homepage():
global root
root = Tk()
root.geometry('300x400')
root.title('CAR FLEET MANAGEMENT SYSTEM')
back_image = PhotoImage(file='icons/background3.png')
back_label = Label(root, image=back_image)
back_label.place(x=0, y=0, relwidth=1, relheight=1)
menus = Menu()
cst = Menu(menus, tearoff=FALSE)
cst.add_command(label="Add New Customer", command=cust_add)
cst.add_command(label="Change Customer Details", command=cust_edit)
menus.add_cascade(label='CUSTOMERS', menu=cst)
root.config(menu=menus)
root.mainloop()
homepage()

Answer 1

If I understand what you want correctly. It's probably better to create two frames for Add Customer and Update Customer. Then show and hide them as required. Like this the widgets are created once and reused as required. I've tried to change your code as little as possible.
I've used grid and grid_remove to hide and show. I couldn't find a pack_remove.
Edit: Below changed to use pack_forget() which in this simple case seems to work OK.
import tkinter as tk
root = None
data = None
def _add(dt):
global data
data = dt
print(data, 'ADDED')
def _edit(new_dt):
global data
data = new_dt
print('UPDATED')
print("DATA =", data)
def homepage():
global root
def cust_edit():
# c_add.grid_remove() Old grid version replaced by pack version
# c_upd.grid()
c_add.pack_forget() # Hide Add Customer
c_upd.pack() # Show Update Customer
def cust_add():
# c_upd.grid_remove() # Grid version removed.
# c_add.grid()
c_upd.pack_forget() # Hide Update Customer
c_add.pack() # Show Add Customer
root = tk.Tk()
root.geometry('300x400')
root.title('CAR FLEET MANAGEMENT SYSTEM')
c_add = tk.Frame(root)
tk.Label(c_add,text="ADD NAME:").pack()
a_ent = tk.Entry(c_add)
a_btn = tk.Button(c_add, text='ADD', command=lambda: _add(a_ent.get()))
a_ent.pack()
a_btn.pack()
c_upd = tk.Frame(root)
tk.Label(c_upd,text="UPDATE NAME:").pack()
u_ent = tk.Entry(c_upd)
u_btn = tk.Button(c_upd, text='UPDATE', command=lambda: _edit(u_ent.get()))
u_ent.pack()
u_btn.pack()
menus = tk.Menu()
cst = tk.Menu(menus, tearoff=tk.FALSE)
cst.add_command(label="Add New Customer", command=cust_add)
cst.add_command(label="Change Customer Details", command=cust_edit)
menus.add_cascade(label='CUSTOMERS', menu=cst)
root.config(menu=menus)
root.mainloop()
homepage()