from tkinter import *
import datetime

root = Tk()
root.title('Spinbox-Calcular a idade')
root.geometry('400x200')
root.config(bg='#31403C')
data =datetime.datetime.now()
data_ano = data.year
current_time = int(data_ano)
def app():
    v = int(var.get())
    idade = current_time - v
    resultado.set(idade)
var = StringVar()
texto_sub1 = Label(text="Ano de Nascimento",
               font=("Arial", "15", "bold"),bg="#31403C",fg="#bf9000")
texto_sub1.place(relx=0.3, rely=0.05)
a = Spinbox( root,from_=1900, to=data_ano,font=('sans-serif', 14),textvariable=var)
a.place(relx=0.4,rely=0.25,relwidth=0.2)
b = Button(text="Calcular Idade", command=app,bg='#107db2', fg='white',
              font=('verdana', 10, 'bold'))
b.place(relx=0.35,rely=0.45,relwidth=0.3, relheight=0.2)
resultado = StringVar()
resultado_texto = Label(textvariable=resultado,
                           font=("Arial", 12, "bold"),bg="#d9ead3" )
resultado_texto.place(relx=0.25, rely=0.7, relwidth=0.45,relheight=0.25)
root.mainloop()