Python Tkinter Entry() 计算

Question

我目前正在尝试在 tkinter 的帮助下使用 python 构建一个 GUI 计算器。我已经设法设置了我所有的按钮，并且当我按下按钮时它们与我的 entry() 栏交互（例如：按下按钮 5 并且 5 出现在 entry() 中）。

唯一剩下要做的就是实际执行 entry() 中出现的数学方程式。例如，如果我在输入栏中输入 5 + 5 * 2，我将如何在更新后让答案出现在 entry() 中？所以基本上我所要求的只是有人帮助我实现这一目标！

我提供了下面的代码和计算器的屏幕截图。另外请不要将此报告为重复或将此问题标记为 post，（我重新提出这个问题是因为我在上一个问题上没有得到任何帮助所以请帮助年轻的 python 程序员！）。另外，我要求您不要向我提供 links，因为我已经阅读了 tkinter 上所有可能的 link，但仍然不知道我在做什么。

这是我的代码：

import sys
from tkinter import *
from PIL import Image, ImageTk

#ACTIONS:
def clear():
    #Action: Clears the entry().
    txtDisplay.delete(0,END);
    return;

def update_Entry(inputValue):
    #Updates the entry when a button is pressed.
    currentText = num1.get();
    update = num1.set(currentText + inputValue);

#Parent Window.
root = Tk();
root.title('Calculator ++ [1.7.2]');
root.geometry('350x450');

#Main entry.
num1 = StringVar();
txtDisplay = Entry(root, textvariable = num1, relief=RIDGE, bd = 10, width=33, insertwidth = 1, font = 40, justify=RIGHT);
txtDisplay.place(x=15, y=10);
txtDisplay.focus();

print(txtDisplay.get())

#Buttons:
zeroButton = Button(root, text='0', width=20, height=3, bg='LightBlue', fg='red', command=lambda:update_Entry('0'));
zeroButton.place(x=17,y=382);
oneButton = Button(root, text='1', width=8, height=3, bg='LightBlue', fg='red', command=lambda:update_Entry('1'));
oneButton.place(x=17, y=302);
twoButton = Button(root, text='2', width=8, height=3, bg='LightBlue', fg='red', command=lambda:update_Entry('2'));
twoButton.place(x=100, y=302);
threeButton = Button(root, text='3', width=8, height=3, bg='LightBlue', fg='red', command=lambda:update_Entry('3'));
threeButton.place(x=182, y=302);
fourButton = Button(root, text='4', width=8, height=3, bg='LightBlue', fg='red', command=lambda:update_Entry('4'));
fourButton.place(x=17, y=222);
fiveButton = Button(root, text='5', width=8, height=3, bg='LightBlue', fg='red', command=lambda:update_Entry('5'));
fiveButton.place(x=100, y=222);
sixButton = Button(root, text='6', width=8, height=3, bg='LightBlue', fg='red', command=lambda:update_Entry('6'));
sixButton.place(x=182, y=222);
sevenButton = Button(root, text='7', width=8, height=3, bg='LightBlue', fg='red', command=lambda:update_Entry('7'));
sevenButton.place(x=17, y=142);
eightButton = Button(root, text='8', width=8, height=3, bg='LightBlue', fg='red', command=lambda:update_Entry('8'));
eightButton.place(x=100, y=142);
ninthButton = Button(root, text='9', width=8, height=3, bg='LightBlue', fg='red', command=lambda:update_Entry('9'));
ninthButton.place(x=182, y=142);

decimalButton = Button(root, text='.', width=8, height=3, bg='powder blue', command=lambda:update_Entry('.'));
decimalButton.place(x=182, y=382);
equalButton = Button(root, text='=', width=8, height=8, bg='Lightgreen', command=lambda:update_Entry('='));
equalButton.place(x=264, y=307);
plusButton = Button(root, text='+', width=8, height=3, bg='gray', command=lambda:update_Entry('+'));
plusButton.place(x=264, y=222);
minusButton = Button(root, text='-', width=8, height=3, bg='gray', command=lambda:update_Entry('-'));
minusButton.place(x=264, y=142);
multiplyButton = Button(root, text='x', width=8, height=3, bg='gray', command=lambda:update_Entry('*'));
multiplyButton.place(x=264, y=66);
divideButton = Button(root, text='÷', width=8, height=3, bg='gray', command=lambda:update_Entry('/'));
divideButton.place(x=182, y=66);
clearButton = Button(root, text='Clear (CE)', width=20, height=3, command = clear, bg='Orange');
clearButton.place(x=17, y=66);

#Locks the parent windows size.
root.maxsize(350,450);
root.minsize(350,450);

#Parent window's background color:
root.configure(background = 'black');
root.mainloop();

截图：

Answer 1

对于这么简单的事情，请尝试将其作为您的 equalButton:

的 command

def evaluate():
    currentText = num1.get()
    try:
        num1.set(str(eval(currentText)))
    except SyntaxError:
        num1.set('<ERROR>')

Python Tkinter Entry() 计算

Python Tkinter Entry() Calculations

python

user-interface

tkinter

calculator

python-3.4