Mobile Application Development with Python: Kivy and PyQT Frameworks
One of the usage areas of Python language is mobile application development. Thanks to popular frameworks such as Kivy and PyQT, it is possible to develop fast and effective mobile applications using the Python language. Here’s what you need to know about Kivy and PyQT frameworks, and some of the challenges you may encounter in mobile app development:
What is Kivy Framework?
Kivy is a Python-based, open-source graphical interface library. It supports multiple operating systems including Android, iOS, Windows, macOS and Linux. In this way, it allows you to develop applications that run on different platforms with a single code base.
Features of Kivy:
Multi-Platform: As mentioned above, Kivy supports multiple operating systems. In this way, you can write your code once and run it on different platforms.
Open Source: Kivy’s source code is freely available and available on GitHub. In this way, you can examine how the library works and customize it according to your needs.
Python Based: Kivy is written in the Python programming language. In this way, you can benefit from the extensive libraries and tools offered by Python.
Easy to Use: Kivy is a relatively easy library to learn and use. There are many resources and sample applications available to get you started.
High Performance: Kivy offers high performance graphics using the SDL2 library.
Disadvantages of Kivy:
Native View: Kivy does not use the native operating system’s graphics tools. Therefore, the appearance of the applications you create may vary from platform to platform.
Limited Widget Set: Kivy offers fewer widgets compared to some other GUI libraries.
Focused on Mobile Application Development: Kivy can also be used to develop desktop applications, but it is primarily focused on mobile application development.
Kivy Usage Areas:
Mobile Applications
Desktop Applications
Games
simulations
Prototyping
More Information About Kivy:
Official Website: https://kivy.org/doc/stable/gettingstarted/installation.html
GitHub Repository: https://github.com/kivy/kivy
Documentation: https://readthedocs.org/projects/kivy/?fromdocs=kivy
Examples: https://kivy.org/doc/stable/guide/basic.html
Installing Kivy Framework:
Download the latest version of Kivy Framework from the official website. (https://kivy.org/#download)
Run the setup file you downloaded and follow the on-screen instructions.
After the installation is complete, open the command line and enter the following command:
pip install kivyAfter the installation is complete, you can start using Kivy Framework in your Python projects.
What are the Features of Kivy?
Kivy offers a rich feature set and includes:
Multi-touch screen support
Animated user interfaces
2D and 3D graphics
OpenGL ES 2 compatible
Compatible with Python 2 and 3
It can run on many platforms such as Android, iOS, Windows, Linux and Mac.
If you want to be efficient while programming with Kivy, it is very important to have basic knowledge about Python classes. In this article, we will examine how classes are used in Kivy and why they are important.
What is Class?
In Python, classes are a way to organize your code and make repetitive operations easier. A class is used to define objects that have common properties and behaviors. Classes can make your code more readable, maintainable and testable.
Why Are Classes Important in Kivy?
Widgets are used to create user interface (UI) elements in Kivy. Widgets are also created using classes. Therefore, it is important to know about classes when programming with Kivy.
Classes are available in Kivy for:
Avoid repetitive codes: If you are going to create many widgets of the same type, you can create a class and create all widgets from this class instead of writing separate code for each widget.
Making code more readable: Classes allow you to make your code more organized and readable. This is especially important in large and complex projects.
Making code more maintainable: Classes make it easier to update and change your code. This increases the maintainability of your code in the long run.
Making code more testable: Classes allow you to test your code more easily. This ensures that your code is free of errors.
Class Usage Example in Kivy:
Below is a simple example of how to use a class to create a button in Kivy:
class Button(kivy.uix.button.Button):
def __init__(self, **kwargs):
super().__init__(**kwargs)
self.text = "Hello World!"# Add a click event handler to the button
self.bind(on_press=self.clicked)
def clicked(self, instance):
print("Button Clicked!")
# Create a button instance and add it to the screen
button = Button()
app = kivy.app.App()
app.build = lambda: button
app.run()In this code, we create a class called Button. This class derives from kivy.uix.button.Button class. This means that the Button class can use all the properties and methods of the kivy.uix.button.Button class.
The __init__ method is a special method that is called when a new instance of a class is created. In this method, you change the button’s text to “Hello World!” We set it to and add a click event handler to the button.
The pressed method is a method that is called when the button is clicked. In this method, “Button clicked!” We print the message.
Finally, we create a button instance and add it to the screen.
Conclusion:
Python classes can help you gain efficiency while programming with Kivy. Classes can make your code more organized, readable, maintainable and testable.
First Application with Kivy: Code Analysis
In this text, we will examine the steps of creating a simple application with Kivy and the functions of the lines of code.
- Code Entry Section:
#!/usr/bin/python3
import kivy
kivy.require('1.10.1') # Check Kivy versionFirst line: This line is used to enable execution with Python 3 on Linux systems. If you’re using Windows or macOS, you can remove this line.
Second line: This line checks the Kivy library and version. It states that you need at least version 1.10.1 of Kivy.
2. Importing Required Libraries:
from kivy.app import App
from kivy.uix.label import LabelFirst line: This line imports the App class from the kivy.app module. The App class is used to form the basis of Kivy applications.
Second line: This line imports the Label class from the kivy.uix.label module. Label class is used to display text on the screen.
3. Main Program Class:
class Program(App):
def build(self):
return Label(text="Hello World!")
Program class: This class forms the basis of the Kivy application by inheriting from the App class.
build method: This method returns the main layout or components that will be displayed on the screen when the program runs. In this method, we say “Hello World!” We return a Label widget that displays the text.
4. Running a Program:
if __name__ == "__main__":
Program().run()if __name__ == “__main__”: : This block ensures that the code is executed only when run directly (not as a module).
Program().run(): This line calls the run() method of the Program class and starts the Kivy application.
In this simple Kivy application, we imported the necessary libraries, created the main program class and said “Hello World!” on the screen. We returned a Label widget that shows the text. Finally, we called the run() method to run the program.
Kivy Application Development with Kv Language
In this text, you can use the kv language in Kivy to say “Hello World!” We will examine how you can create the application.
1. Master File Preparation:
main.py:
This file will contain the Python code for your program.
Set the file name and encoding.
Create a class named Program and inherit from App class.
At this stage, you do not need to write any code inside the class.
2. Creating Kv File:
program.kv:
This file will define the user interface (UI) of your program in the kv language.
Set the filename according to the class name in the main.py file.
“Hello World!” using the Label widget. print the text to the screen.
3. Code Analysis:
main.py:
#!/usr/bin/env python
# -*- coding: utf-8 -*-
from kivy.app import App
class Program(App):
pass
Program().run()Encoding: Indicates that the UTF-8 character set is used.
Import: Imports the App class from the kivy.app module.
Program Class:
It inherits from the App class.
It does not contain any code at this stage.
Run: Creates an instance of the program class and calls the run() method.
program.kv:
Label:
text: "Hello World"Label Widget:
It is used to show text on the screen.
The text property specifies the text to display.
4. Operation:
Run the main.py file.
“Hello World!” text will appear on the screen.
About Kv Language:
Kv language is used to define the UI when programming with Kivy.
It has a simpler and more readable syntax compared to Python.
WYSIWYG tools can also be used to visually design the UI.
The Kv language can be used in conjunction with Python code or independently.
Advantages of Kv Language:
Faster and easier UI development
More readable and maintainable code
Visual design opportunity with WYSIWYG tools
Flexibility and power with Python code
Kv language is a powerful tool that makes UI development easier and faster when programming with Kivy.
Kivy Application Features
In this article, we will examine how you can change the window title and other properties in your Kivy application.
1. Changing Window Title:
main.py:
#!/usr/bin/env python
# -*- coding: utf-8 -*-
from kivy.app import App
from kivy.uix.label import Label
class Program(App):
def build(self):
self.title = "KİVY APP" # Adjust window title
return Label(text="Hello World")
Program().run()self.title: This property is used to set the window title.
2. on_start() Method:
This method is run before the program starts and can be used to set initial settings.
main.py:
#!/usr/bin/env python
# -*- coding: utf-8 -*-
from kivy.app import App
from kivy.uix.label import Label
class Program(App):
def on_start(self):
self.title = "KİVY APP" # Adjust window title
# You can perform operations such as starting a database connection here
def build(self):
return Label(text="Hello World")
Program().run()on_start: This method is run before the program starts.
Initial Settings: You can adjust settings such as the window title here.
Database Connection: You can also perform operations such as database connection here.
3. Other Methods:
on_stop(): This method is run when the program ends. You can perform final operations (such as closing open files) here.
on_pause(): This method is run when the program is backgrounded (on Android or iOS).
on_resume(): This method is run when the program is restored from the background.
Notes:
The on_start() method is called after executing the build() method.
These methods can be used to improve your program’s functionality and user experience.
What is PyQT Framework?
PyQT is an open source Python library and GUI (Graphical User Interface) framework. This framework is a tool used to develop desktop applications.
What are the Features of PyQT?
PyQT offers a number of features including:
Multi-platform support
WYSIWYG design tool
Qt Designer interface
An open source tool
QtWebKit and QtOpenGL support
Challenges Encountered While Developing Mobile Applications
Some of the challenges that may be encountered in the mobile application development process are:
Providing multi-platform support
Designing for different screen sizes
Avoid slowdowns that can cause performance issues
Ensuring data security of the application
Conclusion
Kivy and PyQT are two popular frameworks that facilitate mobile app development using the Python language. Both frameworks have a rich feature set and can run on different platforms. However, some difficulties may be encountered in the mobile application development process and therefore the development process must be carefully planned.
Multi-platform support can be provided with tools such as Kivy and PyQt using the Python programming language. Kivy and PyQt are Python libraries used to design user interface (UI).
Kivy is an open source framework and can run on many platforms such as mobile devices, desktops, and websites. Kivy offers many features to easily create graphical interfaces and is also optimized for touchscreens. Kivy is especially ideal for mobile apps.
PyQt, on the other hand, is a Qt library linker written in Python. Qt is a C++ library that provides multi-platform support. PyQt is used to develop GUI applications using the Python language Qt library classes. With PyQt, you can create graphical applications that run on many operating systems such as Windows, macOS, and Linux.
Therefore, using the Python programming language, it is possible to develop multi-platform support and mobile, desktop and web applications with tools such as Kivy and PyQt.
Installing Python Kivy and PyQt Frameworks is quite simple. Assuming you have Python installed on your operating system, you can install these frameworks by following the steps below:
Installing PyQt Framework:
Download the latest version of PyQt Framework from the official website. (https://www.riverbankcomputing.com/software/pyqt/download5)
Run the setup file you downloaded and follow the on-screen instructions.
After the installation is complete, open the command line and enter the following command:
pip install pyqt5After the installation is complete, you can start using the PyQt Framework in your Python projects.
Note: Installation steps may vary depending on your operating system and Python version. Follow the installation steps carefully and if you encounter error messages, you can seek help from the relevant websites or forums.
