index.py

import tkinter as tk

def fahrenheit_to_celsius():
    try:
        f = float(ent_temperature.get())  
        c = (f - 32) * 5 / 9             
        lbl_result.config(text=f"{round(c, 2)}\N{DEGREE CELSIUS}")  
    except ValueError:
        lbl_result.config(text="Invalid input")  

window = tk.Tk()
window.title("Temperature Converter")
window.resizable(width=False, height=False)

frm_entry = tk.Frame(master=window)
ent_temperature = tk.Entry(master=frm_entry, width=10)
lbl_temp = tk.Label(master=frm_entry, text="\N{DEGREE FAHRENHEIT}")

ent_temperature.grid(row=0, column=0, sticky="e")
lbl_temp.grid(row=0, column=1, sticky="w")

btn_convert = tk.Button(master=window, text="\N{RIGHTWARDS BLACK ARROW}", command=fahrenheit_to_celsius)
lbl_result = tk.Label(master=window, text="\N{DEGREE CELSIUS}")

frm_entry.grid(row=0, column=0, padx=10)
btn_convert.grid(row=0, column=1, pady=10)
lbl_result.grid(row=0, column=2, padx=10)

window.mainloop()