如何使用Python中的tkinter构建简单的GUI计算器

在日常生活和工作中，我们经常需要进行计算。与其写代码或者打开复杂的软件来进行计算，不如构建一个简单的计算器来提高效率。而Python作为一种优秀的编程语言，提供了很好的GUI工具——tkinter。在本篇文章中，我们将会学习如何使用Python中的tkinter构建一个简单的GUI计算器。

步骤1：导入tkinter模块

首先，在Python中使用tkinter构建一个GUI窗口需要先导入tkinter模块。

from tkinter import *

步骤2：创建GUI窗口

接下来，我们需要创建GUI窗口。

window = Tk()
window.title("Simple Calculator")

以上代码将会创建一个名为“Simple Calculator”的GUI窗口。

步骤3：添加文本框

接下来，我们需要在GUI窗口中添加文本框用于显示计算结果。

text_box = Entry(window, width=40, borderwidth=5)
text_box.grid(row=0, column=0, columnspan=4, padx=10, pady=10)

以上代码将创建一个宽为40字符的文本框，并放置在第一行第一列，占据4列。参数“padx”和“pady”将会在文本框周围分别添加10像素的空白边框。

步骤4：创建按键

接下来，我们需要在GUI窗口中添加按键用于进行计算。

button_1 = Button(window, text='1', padx=40, pady=20, command=lambda: button_click(1))
button_2 = Button(window, text='2', padx=40, pady=20, command=lambda: button_click(2))
button_3 = Button(window, text='3', padx=40, pady=20, command=lambda: button_click(3))
button_4 = Button(window, text='4', padx=40, pady=20, command=lambda: button_click(4))
button_5 = Button(window, text='5', padx=40, pady=20, command=lambda: button_click(5))
button_6 = Button(window, text='6', padx=40, pady=20, command=lambda: button_click(6))
button_7 = Button(window, text='7', padx=40, pady=20, command=lambda: button_click(7))
button_8 = Button(window, text='8', padx=40, pady=20, command=lambda: button_click(8))
button_9 = Button(window, text='9', padx=40, pady=20, command=lambda: button_click(9))
button_0 = Button(window, text='0', padx=40, pady=20, command=lambda: button_click(0))
button_add = Button(window, text='+', padx=39, pady=20, command=button_add)
button_subtract = Button(window, text='-', padx=41, pady=20, command=button_subtract)
button_multiply = Button(window, text='*', padx=40, pady=20, command=button_multiply)
button_divide = Button(window, text='/', padx=41, pady=20, command=button_divide)
button_equals = Button(window, text='=', padx=89, pady=20, command=button_equals)
button_clear = Button(window, text='Clear', padx=79, pady=20, command=button_clear)

以上代码将会创建计算器所需的所有按键。

步骤5：定义按键功能

接下来，我们需要为按键定义相应的功能。

def button_click(number):
    current = text_box.get()
    text_box.delete(0, END)
    text_box.insert(0, str(current) + str(number))

def button_add():
    first_number = text_box.get()
    global f_num
    global math
    math = "addition"
    f_num = int(first_number)
    text_box.delete(0, END)

def button_subtract():
    first_number = text_box.get()
    global f_num
    global math
    math = "subtraction"
    f_num = int(first_number)
   text_box.delete(0, END)

def button_multiply():
    first_number = text_box.get()
    global f_num
    global math
    math = "multiplication"
    f_num = int(first_number)
    text_box.delete(0, END)

def button_divide():
    first_number = text_box.get()
    global f_num
    global math
    math = "division"
    f_num = int(first_number)
    text_box.delete(0, END)

def button_equals():
    second_number = text_box.get()
    text_box.delete(0, END)

    if math == "addition":
        text_box.insert(0, f_num + int(second_number))
    elif math == "subtraction":
        text_box.insert(0, f_num - int(second_number))
    elif math == "multiplication":
        text_box.insert(0, f_num * int(second_number))
    elif math == "division":
        text_box.insert(0, f_num / int(second_number))

def button_clear():
    text_box.delete(0, END)

以上代码将会为所有按键定义相应的功能。

步骤6：将按键放置于GUI窗口中

接下来，我们需要将按键放置于GUI窗口中。

button_1.grid(row=3, column=0)
button_2.grid(row=3, column=1)
button_3.grid(row=3, column=2)

button_4.grid(row=2, column=0)
button_5.grid(row=2, column=1)
button_6.grid(row=2, column=2)

button_7.grid(row=1, column=0)
button_8.grid(row=1, column=1)
button_9.grid(row=1, column=2)

button_0.grid(row=4, column=0)

button_add.grid(row=5, column=0)
button_subtract.grid(row=6, column=0)
button_multiply.grid(row=6, column=1)
button_divide.grid(row=6, column=2)

button_equals.grid(row=5, column=1, columnspan=2)
button_clear.grid(row=4, column=1, columnspan=2)

以上代码将会将所有按键放置于GUI窗口中。

完整代码

最后，让我们来看一下完整的代码。

from tkinter import *

window = Tk()
window.title("Simple Calculator")

text_box = Entry(window, width=40, borderwidth=5)
text_box.grid(row=0, column=0, columnspan=4, padx=10, pady=10)

button_1 = Button(window, text='1', padx=40, pady=20, command=lambda: button_click(1))
button_2 = Button(window, text='2', padx=40, pady=20, command=lambda: button_click(2))
button_3 = Button(window, text='3', padx=40, pady=20, command=lambda: button_click(3))
button_4 = Button(window, text='4', padx=40, pady=20, command=lambda: button_click(4))
button_5 = Button(window, text='5', padx=40, pady=20, command=lambda: button_click(5))
button_6 = Button(window, text='6', padx=40, pady=20, command=lambda: button_click(6))
button_7 = Button(window, text='7', padx=40, pady=20, command=lambda: button_click(7))
button_8 = Button(window, text='8', padx=40, pady=20, command=lambda: button_click(8))
button_9 = Button(window, text='9', padx=40, pady=20, command=lambda: button_click(9))
button_0 = Button(window, text='0', padx=40, pady=20, command=lambda: button_click(0))
button_add = Button(window, text='+', padx=39, pady=20, command=button_add)
button_subtract = Button(window, text='-', padx=41, pady=20, command=button_subtract)
button_multiply = Button(window, text='*', padx=40, pady=20, command=button_multiply)
button_divide = Button(window, text='/', padx=41, pady=20, command=button_divide)
button_equals = Button(window, text='=', padx=89, pady=20, command=button_equals)
button_clear = Button(window, text='Clear', padx=79, pady=20, command=button_clear)

button_1.grid(row=3, column=0)
button_2.grid(row=3, column=1)
button_3.grid(row=3, column=2)

button_4.grid(row=2, column=0)
button_5.grid(row=2, column=1)
button_6.grid(row=2, column=2)

button_7.grid(row=1, column=0)
button_8.grid(row=1, column=1)
button_9.grid(row=1, column=2)

button_0.grid(row=4, column=0)

button_add.grid(row=5, column=0)
button_subtract.grid(row=6, column=0)
button_multiply.grid(row=6, column=1)
button_divide.grid(row=6, column=2)

button_equals.grid(row=5, column=1, columnspan=2)
button_clear.grid(row=4, column=1, columnspan=2)

def button_click(number):
    current = text_box.get()
    text_box.delete(0, END)
    text_box.insert(0, str(current) + str(number))

def button_add():
    first_number = text_box.get()
    global f_num
    global math
    math = "addition"
    f_num = int(first_number)
    text_box.delete(0, END)

def button_subtract():
    first_number = text_box.get()
    global f_num
    global math
    math = "subtraction"
    f_num = int(first_number)
    text_box.delete(0, END)

def button_multiply():
    first_number = text_box.get()
    global f_num
    global math
    math = "multiplication"
    f_num = int(first_number)
    text_box.delete(0, END)

def button_divide():
    first_number = text_box.get()
    global f_num
    global math
    math = "division"
    f_num = int(first_number)
    text_box.delete(0, END)

def button_equals():
    second_number = text_box.get()
    text_box.delete(0, END)

    if math == "addition":
        text_box.insert(0, f_num + int(second_number))
    elif math == "subtraction":
        text_box.insert(0, f_num - int(second_number))
    elif math == "multiplication":
        text_box.insert(0, f_num * int(second_number))
    elif math == "division":
        text_box.insert(0, f_num / int(second_number))

def button_clear():
    text_box.delete(0, END)

window.mainloop()