如何在Python中使用类（类在我的代码中不起作用）

Question

我编写了一个代码，然后决定将其拆分为一个GUI类和一个逻辑类，但是现在我已经做到了在创建两个类之后该代码不起作用，它在没有这些类的情况下也可以工作，但是我试图使其工作与类。 如果有人可以解决此问题，我将非常感激。 任何帮助将不胜感激，谢谢。

from tkinter import *
import tkinter as tk
from tkinter import ttk

class GUI:
    notebook = ttk.Notebook(root)
    frame1 = ttk.Frame(notebook)
    notebook.add(frame1, text='Length')
    frame2 = ttk.Frame(notebook)
    notebook.add(frame2, text='Weight')
    frame3 = ttk.Frame(notebook)
    notebook.add(frame3, text='Temperature')
    notebook.pack(expand=1, fill="both")
    #======================================================================
    entry = Entry(frame1)
    entry.grid(row=0, column=0)

    label = Label(frame1, relief='groove', width=20, text='')
    label.grid(row=0, column=3)

    options1 = ['mm', 'cm', 'm', 'km', 'Inches', 'Feet', 'Yards', 'Miles']

    var1 = tk.StringVar(frame1)
    var1.set(options1[0])

    dropdown1 = tk.OptionMenu(frame1, var1, options1[0], options1[1], options1[2], options1[3], options1[4], options1[5], options1[6], options1[7])
    dropdown1.grid(row=1, column=0)

    var2 = tk.StringVar(frame1)
    var2.set(options1[0])

    dropdown2 = tk.OptionMenu(frame1, var2, options1[0], options1[1], options1[2], options1[3], options1[4], options1[5], options1[6], options1[7])
    dropdown2.grid(row=1, column=3)

    equal_button = Button(frame1, text='=', command=Length_Error) 
    equal_button.grid(row=1, column=5)
    #======================================================================
    weight_entry = Entry(frame2)
    weight_entry.grid(row=0, column=0)

    weight_label = Label(frame2, relief='groove', width=20, text='')
    weight_label.grid(row=0, column=3)

    options2 = ['Grams', 'Kilograms', 'Ounces', 'Pounds', 'Tonnes']

    weight_var1 = tk.StringVar(frame2)
    weight_var1.set(options2[0])

    dropdown1 = tk.OptionMenu(frame2, weight_var1, options2[0], options2[1], options2[2], options2[3], options2[4])
    dropdown1.grid(row=1, column=0)

    weight_var2 = tk.StringVar(frame1)
    weight_var2.set(options2[0])

    dropdown2 = tk.OptionMenu(frame2, weight_var2, options2[0], options2[1], options2[2], options2[3], options2[4])
    dropdown2.grid(row=1, column=3)

    weight_equal_button = Button(frame2, text='=', command=Weight_Error) 
    weight_equal_button.grid(row=1, column=5)
    #======================================================================
    temp_entry = Entry(frame3)
    temp_entry.grid(row=0, column=0)

    temp_label = Label(frame3, relief='groove', width=20, text='')
    temp_label.grid(row=0, column=3)

    options3 = ['Celsius', 'Fahrenheit', 'Kelvin']

    temp_var1 = tk.StringVar(frame3)
    temp_var1.set(options3[0])

    temp_dropdown1 = tk.OptionMenu(frame3, temp_var1, options3[0], options3[1], options3[2])
    temp_dropdown1.grid(row=1, column=0)

    temp_var2 = tk.StringVar(frame3)
    temp_var2.set(options3[0])

    temp_dropdown2 = tk.OptionMenu(frame3, temp_var2, options3[0], options3[1], options3[2])
    temp_dropdown2.grid(row=1, column=3)

    temp_equal_button = Button(frame3, text='=', command=Temperature_Error) 
    temp_equal_button.grid(row=1, column=5)
    #======================================================================

class logic:
    #======================================================================
    def Length_Error(*args):
        try:
            v = float(entry.get())       
        except ValueError:
            label['text']=('Enter Valid Input')
        else:
            Length_converter()
    #======================================================================
    def Weight_Error(*args):
        try:
            v = float(weight_entry.get())
        except ValueError:
            weight_label['text']=('Enter Valid Input')
        else:
            Weight_converter()
    #======================================================================
    def Temperature_Error(*args):
        try:
            v = float(temp_entry.get())
        except ValueError:
            temp_label['text']=('Enter Valid Input')
        else:
            Temperature_converter()
    #======================================================================
    def Length_converter(*args):
        v = float(entry.get())
        metre_dict = dict(mm= 0.001, cm= 0.01, m= 1, km= 1000, Inches= 0.0254, Feet= 0.3048, Yards= 0.9144, Miles= 1609.344)
        M = v * metre_dict[var1.get()]
        k = M / metre_dict[var2.get()]
        label['text']=k
    #======================================================================
    def Weight_converter(*args):
        v = float(weight_entry.get())
        weight_dict = dict(Grams= 1, Kilograms= 1000, Ounces= 28.34952313, Pounds= 453.59237, Tonnes= 1000000)
        M = v * weight_dict[weight_var1.get()]
        k = M / weight_dict[weight_var2.get()]
        weight_label['text']=k
    #======================================================================
    def Temperature_converter(*args):
        temp_dict = dict(Fahrenheit=(1/1.8, -32/1.8), Celsius=(1, 0), Kelvin=(1, -273.15))
        x, y= temp_dict[temp_var1.get()]
        cels = float(temp_entry.get()) * x + y
        x, y = temp_dict[temp_var2.get()]
        answer = (cels - y) / x
        temp_label['text']=answer

        root.mainloop

Answer 1

如果为逻辑创建类，则它应该获取参数并返回结果，而不使用小部件。 Button应该运行从小部件获取值并将其与Logic一起使用的函数，然后再获取结果并放入小部件。

此类Logic不必记住值，因此我认为方法可以是静态的。

在课堂上，我们将代码评级器放入方法中，然后使用self. 在类中的不同方法中可以访问相同的变量

#### from tkinter import *  <-- not preferred

import tkinter as tk
from tkinter import ttk

class GUI:

    def __init__(self):  # <-- init class

        root = tk.Tk()  # <-- main window

        notebook = ttk.Notebook(root)
        frame1 = ttk.Frame(notebook)

        notebook.add(frame1, text='Length')
        frame2 = ttk.Frame(notebook)

        notebook.add(frame2, text='Weight')
        frame3 = ttk.Frame(notebook)

        notebook.add(frame3, text='Temperature')
        notebook.pack(expand=1, fill="both")

        #======================================================================

        self.entry = tk.Entry(frame1)  # <-- self. / tk.
        self.entry.grid(row=0, column=0)  # <-- self.

        self.label = tk.Label(frame1, relief='groove', width=20, text='')  # <-- self. / tk.
        self.label.grid(row=0, column=3)  # <-- self.

        options1 = ['mm', 'cm', 'm', 'km', 'Inches', 'Feet', 'Yards', 'Miles']

        self.var1 = tk.StringVar(frame1)  # <-- self.
        self.var1.set(options1[0])  # <-- self.

        dropdown1 = tk.OptionMenu(frame1, self.var1, *options1)  # <-- self. / *options1
        dropdown1.grid(row=1, column=0)

        self.var2 = tk.StringVar(frame1)  # <-- self.
        self.var2.set(options1[0])  # <-- self.

        dropdown2 = tk.OptionMenu(frame1, self.var2, *options1)  # <-- self. / *options1
        dropdown2.grid(row=1, column=3)

        equal_button = tk.Button(frame1, text='=', command=self.convert_length)   # <-- tk. / function in GUI
        equal_button.grid(row=1, column=5)

        #======================================================================

        self.weight_entry = tk.Entry(frame2)  # <-- self. / tk.
        self.weight_entry.grid(row=0, column=0)  # <-- self.

        self.weight_label = tk.Label(frame2, relief='groove', width=20, text='')  # <-- self. / tk.
        self.weight_label.grid(row=0, column=3)  # <-- self.

        options2 = ['Grams', 'Kilograms', 'Ounces', 'Pounds', 'Tonnes']

        self.weight_var1 = tk.StringVar(frame2)  # <-- self.
        self.weight_var1.set(options2[0])  # <-- self.

        dropdown1 = tk.OptionMenu(frame2, self.weight_var1, *options2)  # <-- self. / *options2
        dropdown1.grid(row=1, column=0)

        self.weight_var2 = tk.StringVar(frame1)  # <-- self.
        self.weight_var2.set(options2[0])  # <-- self.

        dropdown2 = tk.OptionMenu(frame2, self.weight_var2, *options2)  # <-- self. / *options2
        dropdown2.grid(row=1, column=3)

        weight_equal_button = tk.Button(frame2, text='=', command=self.convert_weight)  # <-- tk. / function in GUI
        weight_equal_button.grid(row=1, column=5)

        #======================================================================

        self.temp_entry = tk.Entry(frame3)  # <-- self. / tk.
        self.temp_entry.grid(row=0, column=0)  # <-- self.

        self.temp_label = tk.Label(frame3, relief='groove', width=20, text='')  # <-- self. / tk.
        self.temp_label.grid(row=0, column=3)  # <-- self.

        options3 = ['Celsius', 'Fahrenheit', 'Kelvin']

        self.temp_var1 = tk.StringVar(frame3)  # <-- self.
        self.temp_var1.set(options3[0])  # <-- self.

        temp_dropdown1 = tk.OptionMenu(frame3, self.temp_var1, *options3)  # <-- self. / *options3
        temp_dropdown1.grid(row=1, column=0)

        self.temp_var2 = tk.StringVar(frame3)  # <-- self.
        self.temp_var2.set(options3[0])  # <-- self.

        temp_dropdown2 = tk.OptionMenu(frame3, self.temp_var2, *options3)  # <-- self. / *options3
        temp_dropdown2.grid(row=1, column=3)

        temp_equal_button = tk.Button(frame3, text='=', command=self.convert_temp)   # <-- tk. / function in GUI
        temp_equal_button.grid(row=1, column=5)

        #======================================================================

        root.mainloop()  # <--- () , it starts window

    # <-- functions assigned to buttons

    def convert_length(self):
        var1 = self.var1.get()
        var2 = self.var2.get()

        try:
            value = float(self.entry.get())       
        except ValueError:
            self.label['text'] = 'Enter Valid Input'
            return

        try:
            self.label['text'] = Converter.convert_length(value, var1, var2)
        except Exception as ex:
            self.label['text'] = 'Exception: {}'.format(ex)

    def convert_weight(self):
        var1 = self.weight_var1.get()
        var2 = self.weight_var2.get()

        try:
            value = float(self.weight_entry.get())       
        except ValueError:
            self.weight_label['text'] = 'Enter Valid Input'
            return

        try:
            self.weight_label['text'] = Converter.convert_weight(value, var1, var2)
        except Exception as ex:
            self.weight_label['text'] = 'Exception: {}'.format(ex)

    def convert_temp(self):
        var1 = self.temp_var1.get()
        var2 = self.temp_var2.get()

        try:
            value = float(self.temp_entry.get())       
        except ValueError:
            self.temp_label['text'] = 'Enter Valid Input'
            return

        try:
            self.temp_label['text'] = Converter.convert_temperature(value, var1, var2)
        except Exception as ex:
            self.temp_label['text'] = 'Exception: {}'.format(ex)


class Converter: # <-- UpperCaseName

    @staticmethod
    def convert_length(v, var1, var2):  # <-- lower_case_name / arguments

        metre_dict = dict(mm= 0.001, cm= 0.01, m= 1, km= 1000, Inches= 0.0254, Feet= 0.3048, Yards= 0.9144, Miles= 1609.344)

        M = v * metre_dict[var1]
        k = M / metre_dict[var2]

        return k

    #======================================================================

    @staticmethod
    def convert_weight(v, var1, var2):  # <-- lower_case_name / arguments

        weight_dict = dict(Grams= 1, Kilograms= 1000, Ounces= 28.34952313, Pounds= 453.59237, Tonnes= 1000000)

        M = v * weight_dict[var1]
        k = M / weight_dict[var2]

        return k

    #======================================================================

    @staticmethod
    def convert_temperature(v, var1, var2):  # <-- lower_case_name / arguments

        temp_dict = dict(Fahrenheit=(1/1.8, -32/1.8), Celsius=(1, 0), Kelvin=(1, -273.15))

        x, y= temp_dict[var1]
        cels = v * x + y
        x, y = temp_dict[var2]

        return (cels - y) / x

# --- main ----

if __name__ == '__main__':
    GUI()