Tutorial: Learning Python Library PyQt – PyQt5 and Tkinter

In this tutorial, we will learn how to use the PyQt library in Python for creating graphical user interfaces. PyQt is a set of Python bindings for the Qt application framework and runs on all platforms supported by Qt, including Windows, macOS, and Linux.

To get started, make sure you have PyQt5 installed on your system. You can install it using pip with the following command:

pip install pyqt5

Once PyQt5 is installed, we can start creating our GUI application. PyQt supports two main ways of creating GUIs: using the QtDesigner tool to design the interface visually, or creating the interface programmatically using Python code.

For this tutorial, we will focus on creating the interface programmatically using Python code. Let’s start by creating a simple window:

import sys
from PyQt5.QtWidgets import QApplication, QLabel

app = QApplication(sys.argv)
label = QLabel("Hello PyQt!")
label.show()
sys.exit(app.exec_())

In this code snippet, we first import the necessary modules from the PyQt5 package. We then create a QApplication object, which manages the application’s control flow and main settings. Next, we create a QLabel widget with the text "Hello PyQt!" and show it on the screen. Finally, we use app.exec_() to start the application event loop and sys.exit() to cleanly exit the application when the window is closed.

Next, let’s create a more complex GUI with multiple widgets and layout management. We can use QVBoxLayout to stack widgets vertically or QHBoxLayout to stack widgets horizontally. Here’s an example creating a window with a button and a label:

import sys
from PyQt5.QtWidgets import QApplication, QWidget, QPushButton, QVBoxLayout, QLabel

class MyWidget(QWidget):
    def __init__(self):
        super().__init__()

        layout = QVBoxLayout()
        self.setLayout(layout)

        self.label = QLabel("Hello PyQt!")
        layout.addWidget(self.label)

        self.button = QPushButton("Click me!")
        layout.addWidget(self.button)

app = QApplication(sys.argv)
widget = MyWidget()
widget.show()
sys.exit(app.exec_())

In this code snippet, we define a custom QWidget subclass called MyWidget that contains a QVBoxLayout layout. We add a QLabel widget with the text "Hello PyQt!" and a QPushButton widget with the text "Click me!" to the layout.

This is just a simple example to get you started with PyQt. PyQt offers a wide range of widgets, layout managers, and signal-slot connections for creating powerful and interactive GUI applications in Python. I encourage you to explore the PyQt documentation and examples to learn more about its capabilities.

That’s it for this tutorial on learning PyQt in Python. I hope you found it helpful in getting started with creating GUI applications using PyQt. Happy coding!