Python Tkinter 中的数学函数和错误消息

Question

我必须用 Tkinter 在 Python 中创建一个 5 函数计算器，它处理 2 个变量并提供一个出口。还需要有错误消息。我已经布置了计算器并定义了功能，但没有任何反应。此外，任何想法如何添加错误消息。现在，当您按下按钮时，错误消息（插入函数的名称）缺少 1 个必需的位置参数：'app'。我完全被卡住了，无法弄清楚。我显然对此很陌生。我相信这很简单。谢谢！

from tkinter import *    
from math import *
app = Tk()
app.title('Calculator')
app.geometry('400x500')

Label(app, text = "Welcome to Calculator 2013. Enjoy!").pack(padx = 10, pady = 10) 
Label(app, text = "Enter both of your variables and then pick your computations below.").pack(pady = 10)   

global var1, var2, total
Label(text='First Variable').pack()
var1 = Entry()
var1.insert(0,0)
var1.pack()
Label(text='Final Variable').pack()
var2 = Entry()
var2.insert(0,0)
var2.pack()
Label(text='Total').pack()
Total = Entry()
Total.pack()


def add():
    global var1, var2, total
    first = float(var1.get())
    second = float(entry.get())
    total = first + second
    total.delete(0,END)
    total.insert(0, str(total))      
def subtract(app):
    global var1, var2, total
    first = float(var1.get())
    second = float(var2.get())
    total = first - second
    total.delete(0,END)
    total.insert(0, str(total))
def divide(app):
    global var1, var2, total
    first = float(var1.get())
    second = float(var2.get())
    total = first / second
    total.delete(0,END)
    total.insert(0, str(total))
def multiply(app):
    global var1, var2, total
    first = float(var1.get())
    second = float(var2.get())
    total = first * second
    total.delete(0,END)
    total.insert(0, str(total))
def clear(app):
    global var1, var2, total
    var1.delete(0,END)
    var2.delete(0,END)
    total.delete(0,END)
def quit(app):
    app.destroy()


b_add = Button(app, text="+", bg="green", fg="black", width = 5, font=12, command = add).pack(side=LEFT)
b_sub = Button(app, text="-", bg="red", fg="white", width = 5, font=12, command = subtract).pack(side=LEFT)
b_sub = Button(app, text="*", bg="blue", fg="white", width = 5, font=12, command = multiply).pack(side=LEFT)
b_div = Button(app, text="/", bg="yellow", fg="black", width = 5, font=12, command = divide).pack(side=LEFT)
b_clear = Button(app, text="Clear", bg="black", fg="white", width = 5, font=12, command = clear).pack(side=LEFT)
b_exit = Button(app, text="Exit?", bg="white", fg="red", width = 40, font=12, command = quit).pack(side=LEFT)


app.protocol("WM_DELETE_WINDOW", quit)
app.mainloop()

Answer 1

错误消息“缺少 1 个必需的位置参数：‘app’。”源于您已经定义了大多数函数来接受名为“app”的参数，但是当您按下按钮时，您并没有传递该参数。简单的解决方案是从定义中删除 app功能。

例如，这样做：

def multiply():
    ...

而不是这样：

def multiply(app):
    ...