Python PyQt time display

Python PyQt Connecting Signals to Slots: Exercise-12 with Solution

Write a Python program that creates an application with a window that displays the current time. Use the PyQt module.

From doc.qt.io:

QApplication Class: The QApplication class manages the GUI application's control flow and main settings.

QWidget Class: The QWidget class is the base class of all user interface objects.

QLabel Class: The QLabel widget provides a text or image display.

QVBoxLayout Class: The QVBoxLayout class lines up widgets vertically.

QTimer Class: The QTimer class provides repetitive and single-shot timers.

QTime Class: The QTime class provides clock time functions.

Sample Solution:

Python Code:

import sys
from PyQt5.QtWidgets import QApplication, QWidget, QLabel, QVBoxLayout
from PyQt5.QtCore import QTimer, QTime

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

        self.setWindowTitle("Time Display")
        self.setGeometry(100, 100, 300, 100)  # (x, y, width, height)

        layout = QVBoxLayout()

        # Create a label for displaying the time
        self.time_label = QLabel(self)
        layout.addWidget(self.time_label)

        self.setLayout(layout)

        # Create a QTimer that updates the time label every second
        self.timer = QTimer(self)
        self.timer.timeout.connect(self.update_time)
        self.timer.start(1000)  # Update every 1000 milliseconds (1 second)

    def update_time(self):
        # Get the current time and set it on the label
        current_time = QTime.currentTime().toString("hh:mm:ss")
        self.time_label.setText(f"Current Time: {current_time}")

def main():
    app = QApplication(sys.argv)
    window = TimeDisplayApp()
    window.show()
    sys.exit(app.exec_())

if __name__ == "__main__":
    main()

Explanation:

In the exercise above -

• Import the necessary modules from PyQt5.
• Create a custom "QWidget" class named "TimeDisplayApp" that builds the main application window.
• Inside the window, there's a label (self.time_label) for displaying the current time.
• Set up a QTimer (self.timer) that triggers the update_time slot function every second (1000 milliseconds).
• In the "update_time()" slot function, we get the current time and set it on the label. This function runs every second, so the label updates with the current time automatically.
• In the main function, we create the PyQt application, instantiate the TimeDisplayApp class, and show the main window.

Output:

Flowchart:

Python Code Editor:

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