How to switch between two tkinter frames

Question

I am trying to switch and display two frames in tkinter using the codes below but I am not succeeding. I have attached an image of what the code is displaying.

from tkinter import*
    root= Tk()
    root.title("HOSPITAL MANAGEMENT SYSTEM")
    root.geometry('600x350')
    #=======frames====
    HR=Frame(root)
    Schain=Frame(root)
    #=========================functions for switching the frames========
    def change_to_HR():
        HR.pack(fill='BOTH', expand=1)
        Schain.pack_forget()
        def change_to_Schain():
            Schain.pack(fill='BOTH', expand=1)
            HR.pack_forget()
        #=====================Add heading logo in the frames======
        labelHR=Label(HR, text="HR DEPARTMENT")
        labelHR.pack(pady=20)
    
        labelSchain=Label(Schain, text="SUPPLY CHAIN DEPARTMENT")
        labelSchain.pack(pady=20)
        #===============================add button to switch between frames=====
        btn1=Button(root, text="HR", command=change_to_HR)
        btn1.pack(pady=20)
        btn2=Button(root, text="SUPPLY CHAIN", command=change_to_Schain)
        btn2.pack(pady=20)
    root.mainloop()

Answer 1

The mistake is in the following lines:

HR.pack(fill='BOTH', expand=1)
Schain.pack(fill='BOTH', expand=1)

You must either directly give the string in lowercase as 'both' or use the pre-defined tkinter constant BOTH. On changing 'BOTH' to BOTH in both the places, your code works properly.

---

Working Code:

from tkinter import *
root= Tk()
root.title("HOSPITAL MANAGEMENT SYSTEM")
root.geometry('600x350')

#=======frames====
HR=Frame(root)
Schain=Frame(root)

#=========================functions for switching the frames========
def change_to_HR():
    HR.pack(fill=BOTH, expand=1)
    Schain.pack_forget()

def change_to_Schain():
    Schain.pack(fill=BOTH, expand=1)
    HR.pack_forget()

#=====================Add heading logo in the frames======
labelHR=Label(HR, text="HR DEPARTMENT")
labelHR.pack(pady=20)

labelSchain=Label(Schain, text="SUPPLY CHAIN DEPARTMENT")
labelSchain.pack(pady=20)
#===============================add button to switch between frames=====
btn1=Button(root, text="HR", command=change_to_HR)
btn1.pack(pady=20)
btn2=Button(root, text="SUPPLY CHAIN", command=change_to_Schain)
btn2.pack(pady=20)

root.mainloop()