I made a calculator with tkinter(obviously in python) and it is meant to ask for user input, and depending on the input, show a result on the screen. However, it doesnt wait for input and just prints the result instead!

Heres the code:

#import modules
import tkinter as tk
import os
import time


window = tk.Tk()
end = window.mainloop

header= tk.Label(
    text = "Calculator",
    fg = "black",
    bg = "white",
)
header.pack()
entry = tk.Entry()
label = tk.Label(text="Enter your first number:")
label.pack()
entry.pack()
ans1 = entry.get()
time.sleep(1)

label2 = tk.Label(text="Enter your second number:")
label2.pack()
entry2 = tk.Entry()
entry2.pack()
ans2 = entry2.get()
time.sleep(1)

label3 = tk.Label(text="Enter your operator:")
label3.pack()
entry3 = tk.Entry()
entry3.pack()
ans3 = entry3.get()
time.sleep(10)
if ans3 == "add":
    result = ans1 + ans2
elif ans3 == "sub":
    result = ans1 - ans2
elif ans3 == "mul":
    result = ans1 * ans2
elif ans3 == "div":
    result = ans1 / ans2
elif ans3 == "mod":
    result = ans1 % ans2
elif ans3 == "pow":
    result = ans1 ** ans2
else:
    result = "error"

label4 = tk.Label(text="The result is:")
label4.pack()
label5 = tk.Label(text=result)
label5.pack()


end()

I made a calculator with tkinter(obviously in python) and it is meant to ask for user input, and depending on the input, show a result on the screen. However, it doesnt wait for input and just prints the result instead!

Heres the code:

#import modules
import tkinter as tk
import os
import time


window = tk.Tk()
end = window.mainloop

header= tk.Label(
    text = "Calculator",
    fg = "black",
    bg = "white",
)
header.pack()
entry = tk.Entry()
label = tk.Label(text="Enter your first number:")
label.pack()
entry.pack()
ans1 = entry.get()
time.sleep(1)

label2 = tk.Label(text="Enter your second number:")
label2.pack()
entry2 = tk.Entry()
entry2.pack()
ans2 = entry2.get()
time.sleep(1)

label3 = tk.Label(text="Enter your operator:")
label3.pack()
entry3 = tk.Entry()
entry3.pack()
ans3 = entry3.get()
time.sleep(10)
if ans3 == "add":
    result = ans1 + ans2
elif ans3 == "sub":
    result = ans1 - ans2
elif ans3 == "mul":
    result = ans1 * ans2
elif ans3 == "div":
    result = ans1 / ans2
elif ans3 == "mod":
    result = ans1 % ans2
elif ans3 == "pow":
    result = ans1 ** ans2
else:
    result = "error"

label4 = tk.Label(text="The result is:")
label4.pack()
label5 = tk.Label(text=result)
label5.pack()


end()

I have tried using time.sleep()to make it wait for input and then show the result. but it just waits before opening the program GUI.