Python - Creating Graphical User Interfaces - 華氏を摂氏に変換、浮動小数点数、tkinter、DoubleVar

Practical Programming
楽天ブックス 紀伊国屋書店

開発環境

• macOS Catalina - Apple (OS)
• Emacs (Text Editor)
• Windows 10 Pro (OS)
• Visual Studio Code (Text Editor)
• Python 3.8 (プログラミング言語)

Practical Programming: An Introduction to Computer Science Using Python 3.6 (Paul Gries(著)、Jennifer Campbell(著)、Jason Montojo(著)、Pragmatic Bookshelf)のChapter 16(Creating Graphical User Interfaces)、Exercise 5.の解答を求めてみる。

コード

#!/usr/bin/env python3
import tkinter


class F2C:
    def __init__(self, parent):
        self.parent = parent
        # Model
        self.fahrenheit = tkinter.DoubleVar()
        self.celsius = tkinter.DoubleVar()
        # View
        self.label = tkinter.Label(
            self.parent, text='Temperature in Fahrenheit')
        self.label.pack()
        self.entry = tkinter.Entry(self.parent, textvariable=self.fahrenheit)
        self.entry.pack()
        self.label_celsius = tkinter.Label(
            self.parent, textvariable=self.celsius)
        self.label_celsius.pack()
        self.convert = tkinter.Button(self.parent,
                                      text='convert',
                                      command=self.f2c)
        self.convert.pack()
        self.quit = tkinter.Button(
            self.parent, text='quit', command=self.parent.destroy)
        self.quit.pack()

    # Controller
    def f2c(self):
        self.celsius.set((self.fahrenheit.get() - 32) * 5 / 9)


if __name__ == "__main__":
    app = tkinter.Tk()
    counter = F2C(app)
    app.mainloop()

入出力結果(Zsh、PowerShell、Terminal、Jupyter(IPython))

% ./sample5.py
%