Python クラスを継承しても変数が継承されない

前提・実現したいこと

Pythonでtkinterを用いて整数の四則演算のみの電卓を作成しています。
電卓機能のクラスDentakuとそれ以外の数値の入力、ウィジェットの設定を定義するクラスMyFrameを組み合わせて作ろうとしています。

発生している問題・エラーメッセージ

ボタンで数値（first_term,second_term）入力をしても電卓機能のクラスDentakuに継承されない。
first_term,second_termともにprintすると０と出力される。

該当のソースコード

Python
1import tkinter as tk
2
3# 第一項
4first_term = 0
5# 第二項
6second_term = 0
7# 結果
8result = 0
9# 入力中の数字
10current_number = 0
11
12
13def do_plus():
14    global current_number
15    global first_term
16    global ennzannshi
17    first_term = current_number
18    current_number = 0
19    ennzannshi = "+"
20
21
22def do_eq():
23    global second_term
24    global result
25    global current_number
26    global ennzannshi
27    second_term = current_number
28    if ennzannshi == "-":
29        result = first_term - second_term
30    elif ennzannshi == "+":
31        result = first_term + second_term
32    elif ennzannshi == "*":
33        result = first_term * second_term
34    elif ennzannshi == "/" and second_term == 0:
35        pass
36    else:
37        result = first_term // second_term
38    current_number = 0
39
40
41class Dentaku():
42    def __init__(self):
43        self.first_term = 0
44        self.second_term = 0
45        self.second_term = 0
46        self.result = 0
47        self.operation = "+"
48
49    def do_operation(self):
50        if self.operation == "+":
51            self.result = self.first_term + self.second_term
52        elif self.operation == "-":
53            self.result = self.first_term - self.second_term
54        elif self.operation == "*":
55            self.result = self.first_term * self.second_term
56        elif self.operation == "/":
57            self.result = self.first_term // self.second_term
58
59
60
61class MyFrame(tk.Frame, Dentaku):
62    def __init__(self, master=None):
63        super().__init__(master)
64
65        self.first_term = dentaku.first_term
66        self.second_term = dentaku.second_term
67        b1 = tk.Button(self, text='1', command=lambda: self.key(1), bg='#ffffff', width=2, font=('Helvetica', 14))
68        b2 = tk.Button(self, text='2', command=lambda: self.key(2), bg='#ffffff', width=2, font=('Helvetica', 14))
69        b3 = tk.Button(self, text='3', command=lambda: self.key(3), bg='#ffffff', width=2, font=('Helvetica', 14))
70        b4 = tk.Button(self, text='4', command=lambda: self.key(4), bg='#ffffff', width=2, font=('Helvetica', 14))
71        b5 = tk.Button(self, text='5', command=lambda: self.key(5), bg='#ffffff', width=2, font=('Helvetica', 14))
72        b6 = tk.Button(self, text='6', command=lambda: self.key(6), bg='#ffffff', width=2, font=('Helvetica', 14))
73        b7 = tk.Button(self, text='7', command=lambda: self.key(7), bg='#ffffff', width=2, font=('Helvetica', 14))
74        b8 = tk.Button(self, text='8', command=lambda: self.key(8), bg='#ffffff', width=2, font=('Helvetica', 14))
75        b9 = tk.Button(self, text='9', command=lambda: self.key(9), bg='#ffffff', width=2, font=('Helvetica', 14))
76        b0 = tk.Button(self, text='0', command=lambda: self.key(0), bg='#ffffff', width=2, font=('Helvetica', 14))
77        bc = tk.Button(self, text='C', command=self.clear, bg='#ff0000', width=2, font=('Helvetica', 14))
78        bp = tk.Button(self, text='+', command=self.plus, bg='#00ff00', width=2, font=('Helvetica', 14))
79        bm = tk.Button(self, text='-', command=self.minus, bg='#00ff00', width=2, font=('Helvetica', 14))
80        bmp = tk.Button(self, text='*', command=self.multiply, bg='#00ff00', width=2, font=('Helvetica', 14))
81        bd = tk.Button(self, text='/', command=self.division, bg='#00ff00', width=2, font=('Helvetica', 14))
82        be = tk.Button(self, text="=", command=self.eq, bg='#00ff00', width=2, font=('Helvetica', 14))
83
84        b1.grid(row=3, column=0)
85        b2.grid(row=3, column=1)
86        b3.grid(row=3, column=2)
87        b4.grid(row=2, column=0)
88        b5.grid(row=2, column=1)
89        b6.grid(row=2, column=2)
90        b7.grid(row=1, column=0)
91        b8.grid(row=1, column=1)
92        b9.grid(row=1, column=2)
93        b0.grid(row=4, column=0)
94        bc.grid(row=1, column=3)
95        be.grid(row=4, column=3)
96        bp.grid(row=2, column=3)
97        bm.grid(row=3, column=3)
98        bmp.grid(row=4, column=1)
99        bd.grid(row=4, column=2)
100
101        self.e = tk.Entry(self, font=('Helvetica', 14))
102        self.e.grid(row=0, column=0, columnspan=4)
103
104    def key(self, n):
105        global current_number
106        current_number = current_number * 10 + n
107        self.show_number(current_number)
108
109    def clear(self):
110        global current_number
111        current_number = 0
112        self.show_number(current_number)
113
114    def plus(self):
115        print(dentaku.first_term)
116        do_plus()
117        dentaku.operation = "+"
118        print(dentaku.operation)
119        print(dentaku.second_term)
120        dentaku.do_operation()
121        print(dentaku.result)
122        self.show_number(dentaku.result)
123
124   
125    def eq(self):
126        do_eq()
127        self.show_number(dentaku.result)
128
129    def show_number(self, num):
130        self.e.delete(0, tk.END)
131        self.e.insert(0, str(num))
132
133
134dentaku = Dentaku()
135root = tk.Tk()
136f = MyFrame(root)
137f.pack()
138f.mainloop()
139

試したこと

表示されるウィンドウの+ボタンを押下すると
0
"+"
0
0
と出力されます

行動規範の内容に同意します

回答1件

ベストアンサー

Dentakuを継承するのではなく、生成した dentaku インスタンスを引数で渡しましょう。
Dentakuは計算を担当するクラス、MyFrame は dentaku を操作する UI (User Interface) クラスに役割分担するといいです。
それらしい実装にしてみました。

python
1import tkinter as tk
2
3
4class Dentaku:
5
6    def __init__(self, show):
7        self.show = show
8        self.operators = {
9            '+': lambda: self.answer + self.number,
10            '-': lambda: self.answer - self.number,
11            '*': lambda: self.answer * self.number,
12            '/': lambda: self.answer // (self.number or 1),
13        }
14        self.clear()
15
16    def clear(self):
17        self.number = 0
18        self.answer = 0
19        self.operator = None
20        self.show(self.answer)
21
22    def entry(self, digit):
23        self.number = self.number * 10 + digit
24        self.show(self.number)
25
26    def operate(self, operator):
27        if self.operator:
28            self.calculate()
29        else:
30            self.answer = self.number
31            self.number = 0
32            self.show(self.answer)
33        self.operator = operator
34        print(self.answer, operator)
35
36    def calculate(self):
37        if self.operator:
38            answer = self.operators[self.operator]()
39            print(self.answer, self.operator, self.number, '=', answer)
40            self.answer = answer
41            self.number = 0
42            self.operator = None
43        self.show(self.answer)
44
45
46class DentakuUI:
47    FONT = ('Helvetica', 14)
48
49    def __init__(self, dentaku, display_variable):
50        display = tk.Entry(textvariable=display_variable, font=self.FONT)
51        k1 = self.number_key(1, dentaku.entry)
52        k2 = self.number_key(2, dentaku.entry)
53        k3 = self.number_key(3, dentaku.entry)
54        k4 = self.number_key(4, dentaku.entry)
55        k5 = self.number_key(5, dentaku.entry)
56        k6 = self.number_key(6, dentaku.entry)
57        k7 = self.number_key(7, dentaku.entry)
58        k8 = self.number_key(8, dentaku.entry)
59        k9 = self.number_key(9, dentaku.entry)
60        k0 = self.number_key(0, dentaku.entry)
61        kp = self.binomial_key('+', dentaku.operate)
62        ks = self.binomial_key('-', dentaku.operate)
63        km = self.binomial_key('*', dentaku.operate)
64        kd = self.binomial_key('/', dentaku.operate)
65        ke = self.unary_key('=', dentaku.calculate)
66        kc = self.unary_key('C', dentaku.clear, bg='#ff0000')
67
68        display.grid(row=0, column=0, columnspan=4)
69        k7.grid(row=1, column=0)
70        k8.grid(row=1, column=1)
71        k9.grid(row=1, column=2)
72        kc.grid(row=1, column=3)
73        k4.grid(row=2, column=0)
74        k5.grid(row=2, column=1)
75        k6.grid(row=2, column=2)
76        kp.grid(row=2, column=3)
77        k1.grid(row=3, column=0)
78        k2.grid(row=3, column=1)
79        k3.grid(row=3, column=2)
80        ks.grid(row=3, column=3)
81        k0.grid(row=4, column=0)
82        km.grid(row=4, column=1)
83        kd.grid(row=4, column=2)
84        ke.grid(row=4, column=3)
85
86    def number_key(self, number, operate, bg='#ffffff'):
87        return tk.Button(text=number,
88                         command=lambda: operate(number),
89                         bg=bg, width=2, font=self.FONT)
90
91    def binomial_key(self, operator, operate, bg='#00ff00'):
92        return tk.Button(text=operator,
93                         command=lambda: operate(operator),
94                         bg=bg, width=2, font=self.FONT)
95
96    def unary_key(self, operator, operate, bg='#00ff00'):
97        return tk.Button(text=operator,
98                         command=operate,
99                         bg=bg, width=2, font=self.FONT)
100
101
102def main():
103    root = tk.Tk()
104    display_variable = tk.IntVar()
105    dentaku = Dentaku(show=display_variable.set)
106    ui = DentakuUI(dentaku, display_variable)
107    root.mainloop()
108
109if __name__ == '__main__':
110    main()