prompter: How do I run background threads in a PyQt5 GUI in Python?

assistant: #this is a background task that displays 'Ten seconds passed' in the PyQt5 main window every ten seconds
#this should be adapted for your perposes
def countTenSeconds():
    #Load PyQt5 GUI
    window = uic.loadUi("mainwindow.ui")
    #Do something
    window.print("Ten seconds passed ")
    #restart task
    threading.Timer(10, countTenSeconds).start()

#Start background task
threading.Timer(10, countTenSeconds).start()

prompter: It actually worked, could you provide an alternative such as PySimpleGUI.

Please.

assistant: Here are five examples on how to run background tasks using PyQt5 in Python:

```py
import sys
import time

from PyQt5.QtCore import (QCoreApplication, QObject, QRunnable, QThread,
                          QThreadPool, pyqtSignal)


# Subclassing QThread
# http://qt-project.org/doc/latest/qthread.html
class AThread(QThread):

    def run(self):
        count = 0
        while count < 5:
            time.sleep(1)
            print("A Increasing")
            count += 1

# Subclassing QObject and using moveToThread
# http://blog.qt.digia.com/blog/2007/07/05/qthreads-no-longer-abstract
class SomeObject(QObject):

    finished = pyqtSignal()

    def long_running(self):
        count = 0
        while count < 5:
            time.sleep(1)
            print("B Increasing")
            count += 1
        self.finished.emit()

# Using a QRunnable
# http://qt-project.org/doc/latest/qthreadpool.html
# Note that a QRunnable isn't a subclass of QObject and therefore does
# not provide signals and slots.
class Runnable(QRunnable):

    def run(self):
        count = 0
        app = QCoreApplication.instance()
        while count < 5:
            print("C Increasing")
            time.sleep(1)
            count += 1
        app.quit()


def using_q_thread():
    app = QCoreApplication([])
    thread = AThread()
    thread.finished.connect(app.exit)
    thread.start()
    sys.exit(app.exec_())

def using_move_to_thread():
    app = QCoreApplication([])
    objThread = QThread()
    obj = SomeObject()
    obj.moveToThread(objThread)
    obj.finished.connect(objThread.quit)
    objThread.started.connect(obj.long_running)
    objThread.finished.connect(app.exit)
    objThread.start()
    sys.exit(app.exec_())

def using_q_runnable():
    app = QCoreApplication([])
    runnable = Runnable()
    QThreadPool.globalInstance().start(runnable)
    sys.exit(app.exec_())

if __name__ == "__main__":
    #using_q_thread()
    #using_move_to_thread()
    using_q_runnable()

prompter: Can you please explain to me how this code is working?

assistant: The code demonstrates 3 different ways to create and run a thread in a PyQt5 application.

1. Subclassing `QThread`: `AThread` is a subclass of `QThread`. It overrides the `run()` method to print "A Increasing" every second for 5 times.

2. Subclassing `QObject` and using `moveToThread`: `SomeObject` is a subclass of `QObject` and has a finished signal. It has a `long_running` method that prints "B Increasing" every second for 5 times and emits the finished signal after the loop is done. The object is moved to a separate thread using `moveToThread` method. When the thread starts, it runs the `long_running` method.

3. Using a `QRunnable`: `Runnable` is a `QRunnable` class. It has a run method that prints "C Increasing" every second for 5 times. The run method is added to a thread pool, which will create a new thread and run the method.

Each of these 3 ways is demonstrated in a separate function. To run each of them, uncomment the corresponding function in the `main` section and comment out the other two.

assistant: This code demonstrates three different ways to run background tasks in a PyQt5 GUI application in Python.

Subclassing QThread:
AThread class is a subclass of the QThread class and overrides the run method. The run method contains the code that will run in the background. In this case, the code contains a while loop that runs 5 times and each time prints "A Increasing" and increments the counter by 1.

Subclassing QObject and using moveToThread:
SomeObject is a subclass of the QObject class and contains the long_running method. The long_running method is similar to the run method in the AThread class, but instead of subclassing QThread, it uses the moveToThread method to run the code in a separate thread. A signal finished is also defined that is emitted when the long_running method has completed execution.

Using a QRunnable:
Runnable is a subclass of the QRunnable class and overrides the run method. This method contains the code that will run in the background. Since QRunnable is not a subclass of QObject, it does not provide signals and slots and therefore doesn't emit signals.

In the main function, each of these methods is demonstrated by creating an instance of the respective class, setting up the connections and starting the thread. The main function then runs the GUI event loop using sys.exit(app.exec_()). This line starts the GUI event loop and waits until the signal finished is emitted and then exits the event loop, which in turn terminates the program.

assistant: This code shows how to execute a task that takes a long time to complete in a PyQt5 application using three methods: subclassing `QThread`, combining `QObject` and `moveToThread`, and using `QRunnable`. Each method involves a loop that runs for five cycles, pausing for one second in each cycle. The main program waits until the task is finished before terminating.

assistant: Like you normally do it, using just the library "threadding"

prompter: Explain what Python's PyQt5 GUI is, and how it is used in threading.

assistant: PyQt5 is a Python binding for the Qt application framework and provides a comprehensive set of Python bindings for the Qt GUI toolkit. It allows developers to create graphical user interfaces (GUIs) for their Python applications.

Threading is a technique in programming where a program is broken down into smaller threads that run concurrently, allowing the program to perform multiple tasks simultaneously. PyQt5 can be used to create a GUI that runs in a separate thread from the main thread of the application, which can help to improve the overall performance and responsiveness of the application.

To use PyQt5 for threading, you can create a separate worker thread that handles long-running or blocking operations, while the main thread remains responsive to user input. The worker thread can communicate with the main thread using signals and slots, which allows them to share data and interact with each other.

PyQt5 provides several classes and modules to support threading, including the QThread class, which is used to create and manage threads, and the QRunnable and QThreadPool classes, which can be used to create thread pools to handle multiple tasks concurrently.

In summary, PyQt5 is a powerful GUI toolkit for Python that allows developers to create interactive and responsive graphical user interfaces for their applications, and it can be used with threading to improve the performance and responsiveness of the application.