Requisito previo: Introducción a Tkinter , función lambda
Python ofrece múltiples opciones para desarrollar una GUI (interfaz gráfica de usuario). De todos los métodos GUI, Tkinter es el método más utilizado. Es una interfaz estándar de Python para el kit de herramientas Tk GUI que se envía con Python. Python con Tkinter genera la forma más rápida y sencilla de crear aplicaciones GUI. Crear una GUI usando Tkinter es una tarea fácil.
Para crear un Tkinter:
- Importando el módulo – tkinter
- Crear la ventana principal (contenedor)
- Agregue cualquier cantidad de widgets a la ventana principal
- Aplique el evento Trigger en los widgets.
A continuación se muestra el aspecto de la GUI:
Vamos a crear una calculadora simple basada en GUI utilizando el módulo Python Tkinter, que puede realizar operaciones aritméticas básicas de suma, resta, multiplicación y división.
A continuación se muestra la implementación:
Python3
# Python program to create a simple GUI
# calculator using Tkinter
# import everything from tkinter module
from tkinter import *
# globally declare the expression variable
expression = ""
# Function to update expression
# in the text entry box
def press(num):
# point out the global expression variable
global expression
# concatenation of string
expression = expression + str(num)
# update the expression by using set method
equation.set(expression)
# Function to evaluate the final expression
def equalpress():
# Try and except statement is used
# for handling the errors like zero
# division error etc.
# Put that code inside the try block
# which may generate the error
try:
global expression
# eval function evaluate the expression
# and str function convert the result
# into string
total = str(eval(expression))
equation.set(total)
# initialize the expression variable
# by empty string
expression = ""
# if error is generate then handle
# by the except block
except:
equation.set(" error ")
expression = ""
# Function to clear the contents
# of text entry box
def clear():
global expression
expression = ""
equation.set("")
# Driver code
if __name__ == "__main__":
# create a GUI window
gui = Tk()
# set the background colour of GUI window
gui.configure(background="light green")
# set the title of GUI window
gui.title("Simple Calculator")
# set the configuration of GUI window
gui.geometry("270x150")
# StringVar() is the variable class
# we create an instance of this class
equation = StringVar()
# create the text entry box for
# showing the expression .
expression_field = Entry(gui, textvariable=equation)
# grid method is used for placing
# the widgets at respective positions
# in table like structure .
expression_field.grid(columnspan=4, ipadx=70)
# create a Buttons and place at a particular
# location inside the root window .
# when user press the button, the command or
# function affiliated to that button is executed .
button1 = Button(gui, text=' 1 ', fg='black', bg='red',
command=lambda: press(1), height=1, width=7)
button1.grid(row=2, column=0)
button2 = Button(gui, text=' 2 ', fg='black', bg='red',
command=lambda: press(2), height=1, width=7)
button2.grid(row=2, column=1)
button3 = Button(gui, text=' 3 ', fg='black', bg='red',
command=lambda: press(3), height=1, width=7)
button3.grid(row=2, column=2)
button4 = Button(gui, text=' 4 ', fg='black', bg='red',
command=lambda: press(4), height=1, width=7)
button4.grid(row=3, column=0)
button5 = Button(gui, text=' 5 ', fg='black', bg='red',
command=lambda: press(5), height=1, width=7)
button5.grid(row=3, column=1)
button6 = Button(gui, text=' 6 ', fg='black', bg='red',
command=lambda: press(6), height=1, width=7)
button6.grid(row=3, column=2)
button7 = Button(gui, text=' 7 ', fg='black', bg='red',
command=lambda: press(7), height=1, width=7)
button7.grid(row=4, column=0)
button8 = Button(gui, text=' 8 ', fg='black', bg='red',
command=lambda: press(8), height=1, width=7)
button8.grid(row=4, column=1)
button9 = Button(gui, text=' 9 ', fg='black', bg='red',
command=lambda: press(9), height=1, width=7)
button9.grid(row=4, column=2)
button0 = Button(gui, text=' 0 ', fg='black', bg='red',
command=lambda: press(0), height=1, width=7)
button0.grid(row=5, column=0)
plus = Button(gui, text=' + ', fg='black', bg='red',
command=lambda: press("+"), height=1, width=7)
plus.grid(row=2, column=3)
minus = Button(gui, text=' - ', fg='black', bg='red',
command=lambda: press("-"), height=1, width=7)
minus.grid(row=3, column=3)
multiply = Button(gui, text=' * ', fg='black', bg='red',
command=lambda: press("*"), height=1, width=7)
multiply.grid(row=4, column=3)
divide = Button(gui, text=' / ', fg='black', bg='red',
command=lambda: press("/"), height=1, width=7)
divide.grid(row=5, column=3)
equal = Button(gui, text=' = ', fg='black', bg='red',
command=equalpress, height=1, width=7)
equal.grid(row=5, column=2)
clear = Button(gui, text='Clear', fg='black', bg='red',
command=clear, height=1, width=7)
clear.grid(row=5, column='1')
Decimal= Button(gui, text='.', fg='black', bg='red',
command=lambda: press('.'), height=1, width=7)
Decimal.grid(row=6, column=0)
# start the GUI
gui.mainloop()
Producción :