Develop a program in Python language with a graphical interface that allows encryption decrypt a string of information using the Cesar code as a variant. You must request offset value

def cesar(cadena, offset):
    lista = []
    for i in range(0, len(cadena)):
        lista.append(chr(ord(cadena[i]) + offset))
    return "".join(lista)

def descifrar(cadena, offset):
    lista = []
    for i in range(0, len(cadena)):
        lista.append(chr(ord(cadena[i]) - offset))
    return "".join(lista)

texto = input("Ingrese el texto a encriptar: ")
offset = int(input("Ingrese el offset: "))
enc = cesar(texto, offset)
print ("Encriptado: ", enc)
desc = descifrar(enc, offset)
print ("Desencriptado: ", desc)