Tkinter - Change Label Text/Entry on Button Click

Question

I have two labels and entry fields (A & B). When I enter the username/password for "A Username/A Password", I want to click the "Submit" button, then have the labels/entry fields change to "B Username/B Password" and be able to click the "Submit" button again, using Tkinter.

Python Code

import tkinter as tk

root = tk.Tk()

a_user_var = tk.StringVar()
a_pass_var = tk.StringVar()

b_user_var = tk.StringVar()
b_pass_var = tk.StringVar()

def submit():

    a_user = a_user_var.get()
    a_pass = a_pass_var.get()

    a_user_var.set("")
    a_pass_var.set("")

    b_user = b_user_var.get()
    b_pass = b_pass_var.get()

    b_user_var.set("")
    b_pass_var.set("")

a_user_label = tk.Label(root, text="A Username")
a_user_entry = tk.Entry(root, textvariable=a_user_var)

a_pass_label = tk.Label(root, text="A Password")
a_pass_entry = tk.Entry(root, textvariable=a_pass_var, show="•")

b_user_label = tk.Label(root, text="B Username")
b_user_entry = tk.Entry(root, textvariable=b_user_var)

b_pass_label = tk.Label(root, text="B Password")
b_pass_entry = tk.Entry(root, textvariable=b_pass_var, show="•")

sub_btn = tk.Button(root, text="Submit", command=submit)

a_user_label.grid(row=0, column=0)
a_user_entry.grid(row=0, column=1)

a_pass_label.grid(row=1, column=0)
a_pass_entry.grid(row=1, column=1)

b_user_label.grid(row=0, column=0)
b_user_entry.grid(row=0, column=1)

b_pass_label.grid(row=1, column=0)
b_pass_entry.grid(row=1, column=1)

sub_btn.grid(row=2, column=0)

root.mainloop()

Current Result

Desired Result (after clicking Submit button)

Answer 1

There is no need to create a unique label and entry widgets for A and B. Instead just use one set of widgets and change the label's text upon pressing the button to B. If you need to store the contents of the entry widget, you can grab the label text and parse it to see which character the specific set belongs to.

For example:

import tkinter as tk

root = tk.Tk()
user_var = tk.StringVar()
pass_var = tk.StringVar()
entries = {}

def submit():
    user = user_var.get()
    passw = pass_var.get()
    label_text = user_label["text"]
    char = label_text.split()[0]
    entries[char] = (user, passw)
    if char == "A":
        user_label["text"] = "B" + label_text[1:]
        pass_label["text"] = "B" + pass_label["text"][1:]
    user_var.set('')
    pass_var.set('')
    print(entries)


user_label = tk.Label(root, text="A Username")
user_entry = tk.Entry(root, textvariable=user_var)

pass_label = tk.Label(root, text="A Password")
pass_entry = tk.Entry(root, textvariable=pass_var, show="•")

sub_btn = tk.Button(root, text="Submit", command=submit)
sub_btn.grid(row=2, column=0)

user_label.grid(row=0, column=0)
user_entry.grid(row=0, column=1)

pass_label.grid(row=1, column=0)
pass_entry.grid(row=1, column=1)

root.mainloop()