【初心者向け】Pythonでデスクトップアプリを作ろう-Kivyを使って♪-

Python is a popular programming language known for its simplicity and versatility. One of the great things about Python is that it can be used to develop desktop applications using various frameworks and libraries. In this tutorial, we will walk you through the process of creating a simple desktop application using Kivy, a Python library for developing multi-touch applications.

Kivy is an open-source Python library that allows you to create multi-touch applications for a wide range of platforms, including Windows, macOS, Linux, iOS, and Android. It is known for its ease of use and flexibility, making it a great choice for beginners and experienced developers alike.

To follow this tutorial, you will need to have Python and Kivy installed on your computer. You can download the latest version of Python from the official website (https://www.python.org/downloads/) and install Kivy using the following command:

pip install kivy

Once you have Python and Kivy installed, you can start creating your desktop application. In this tutorial, we will create a simple calculator application that performs basic arithmetic operations.

Step 1: Setting Up Your Project

Create a new directory for your project and navigate to it using the command line. Then, create a new Python file called calculator.py and open it in your favorite text editor.

mkdir calculator_app
cd calculator_app
touch calculator.py

Step 2: Importing the Required Modules

In your calculator.py file, import the necessary modules from Kivy to create the user interface for your application. Add the following code to your file:

from kivy.app import App
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.button import Button
from kivy.uix.label import Label

Step 3: Creating the User Interface

Next, we will create the user interface for our calculator application. We will use a BoxLayout to organize the buttons and labels in a row. Add the following code to your calculator.py file:

class CalculatorApp(App):

    def build(self):
        layout = BoxLayout(orientation='vertical')

        label = Label(text='0', font_size=50)
        layout.add_widget(label)

        buttons = [
            ['7', '8', '9', '/'],
            ['4', '5', '6', '*'],
            ['1', '2', '3', '-'],
            ['C', '0', '=', '+']
        ]

        for row in buttons:
            row_layout = BoxLayout()
            for button_text in row:
                button = Button(text=button_text, font_size=30)
                button.bind(on_press=self.on_button_press)
                row_layout.add_widget(button)
            layout.add_widget(row_layout)

        return layout

    def on_button_press(self, instance):
        pass

if __name__ == '__main__':
    CalculatorApp().run()

Step 4: Adding Functionality to the Buttons

In the on_button_press method, we will implement the functionality for the calculator buttons. Update the on_button_press method as follows:

    def on_button_press(self, instance):
        current_text = self.root.children[0].text

        if instance.text == 'C':
            self.root.children[0].text = '0'
        elif instance.text == '=':
            try:
                result = str(eval(current_text))
                self.root.children[0].text = result
            except:
                self.root.children[0].text = 'Error'
        else:
            if current_text == '0':
                self.root.children[0].text = instance.text
            else:
                self.root.children[0].text += instance.text

Step 5: Running Your Application

To run your application, navigate to the directory where your calculator.py file is located and run the following command:

python calculator.py

You should see a simple calculator application with buttons for numbers, arithmetic operations, and a label to display the current input. You can click on the buttons to perform basic calculations like addition, subtraction, multiplication, and division.

Congratulations! You have successfully created a Python desktop application using the Kivy library. You can further customize your application by adding more features and improving its user interface. Happy coding!