If an operation is performed periodically in the application, such as periodically detecting the CPU value of the host, then the QTimer timer is needed.

• Jun 22, 2020 Slots in Python is a special mechanism that is used to reduce memory of the objects. In Python, all the objects use a dynamic dictionary for adding an attribute. Slots is a static type method in this no dynamic dictionary are required for allocating attribute.
• See full list on techbase.kde.org.
• In the above example, our slot shows a message box. The term slot is important when using Qt from C, because slots must be declared in a special way in C. In Python however, any function can be a slot – we saw this above. For this reason, the distinction between slots.

When the window’s control receives a Timeout signal, it stops this timer.

Dec 27, 2019 In Python, there is no default functionality to allocate a static amount of memory while creating the object to store all its attributes. Usage of slots reduce the wastage of space and speed up the program by allocating space for a fixed amount of attributes. Example of python object with slots.

QTimer has the method start(milliseconds) and Stop().

Book: Create Desktop Apps with Python PyQt5

QTimer example

The program below has a start and stop button. If you click the start button, it starts a QTimer.

This will update the time every second.

First initialize a timer and connect the timer’s timeout signal to the showTime() slot function

Use the connected slot function to display the current time, with the system’s current time on the label

Click the Start button to start the timer and disable the button

Python Slots Examples

Click the end button to stop the timer and disable the button

Python Slot Machine Code

Book: Create Desktop Apps with Python PyQt5