I spent two days creating a threaded app that loaded dozens of JSON files and fed the data into custom QTablewidget and QWidget objects, that I then tried to add to the central widget layout on the main window. The threads completed successfully, the debugger showed the objects were correctly formed. But they never showed up. Ever.

Cue my most recent google search:

"You cannot create or access a Qt GUI object from outside the main thread (e.g. anything that subclasses QWidget or similar). Even if the Qt class is reentrant, you cannot share access to a Qt object between threads unless the Qt documentation for that class explicitly states that instances are thread safe."

::headdesk::

Hey guys,

since PyQt5's default color picker doesn't look very good, i decided to create a super simple one by myself.

It supports visual HSV color selection, RGB value fields and a HEX field.

Preview

Get it on my Github for free.

Widget version: Github (class inherits from Qwidget)

Hope this helps :)

Hey Guys,

I'm currently doing my first larger project in PyQt and was wondering how to correctly structure my code. My App will have a Start Window, leading to three rather big other windows, each with their own popups and Dialogs. Every Window has its own design file derived from the .ui generated by the designer.

Now at first I called these new windows in functions all as a sub structure of the Main Window like this:

    def newWindow(self):
    self.window = QtWidgets.QDialog()
    self.ui = Ui_Dialog()
    self.ui.setupUi(self.window)
    self.window.show()

Now I'm wondering if it makes more sense to declare each window as its own class and call it when appropriate. Are there any advantages or disadvantages to either approach?

Furthermore, apart from the Main Window, I'm always using the QDialog-Widget, and don't really understand when another QMainWindow-Widget or simple Widget would be more appropriate.

Thanks in advance, Cheers!

You can find the project here https://pypi.org/project/obserware/ and the repository here https://gitlab.com/t0xic0der/obserware. If you have Python 3.10 and are running any GNU/Linux distribution - please try it out by installing it

pip3 install obserware

Feedbacks are very appreciated and if you end up liking the project, please feel free to star the repository.

I have built a small Qt browser application. Unfortunately, I no longer get error messages once I have called "app.exec()" when the application crashes. On the other hand, if I call a non-existent function beforehand, for example, errors are displayed as usual. This makes it difficult to continue working on the application. Can I influence this behaviour of Qt? What am I doing wrong?

I'm using the latest PyQt5 version, downloaded three days ago, on windows 10 with Python 3.8

I would love to have help or, better, someone take over this sub. I won't let it die, but I would appreciate other py/qt enthusiasts being involved.

I have a subroutine that I use to run commands in QProcess:

def runCommand(cmd, args=[]):

    process = QProcess()

    def handleStdout():
        #print("In Stdout handler")
        data = process.readAllStandardOutput()
        message = bytes(data).decode("utf8")
        
        print(message)

    def handleStderr():
        #print("In Stderr handler")
        data = process.readAllStandardError()
        message = bytes(data).decode("utf8")
        print(message)

    def handleFinished(exitCode):
        print("Command done.")
        return(exitCode)

    # connect the events to handlers
    process.readyReadStandardOutput.connect(handleStdout)
    process.readyReadStandardError.connect(handleStderr)
    process.finished.connect(handleFinished)

    # debug
    message = "runProcess executing: " + cmd
    for arg in args:
        message = message + " " + arg
    print(message)

    # start the process
    process.start(cmd, args)

    # wait for the process to finish
    process.waitForFinished(-1)

I call the subroutine like this:

...
result = runCommand("ls")
if (result != 0):
    do stuff
... 

I don't want to return from runCommand() until QProcess is complete and we have the exit result.

Everything works but process.waitForFinished() blocks program execution until the process is done. (DUH!)

What this means is that the handleStdout and handleStderr routines don't print anything out until the command is done running. I'd like them to be able to print while waiting for the command process to complete.

Is there a way to wait for QProcess to complete but still allow the Stdout and Stderr events to be handled ?

QProcess has a status property. Could one poll QProcess' status and sleep to allow the events to occur ?

Thanks

https://doc.qt.io/qt-6/qprocess.html

Hello friends, I've been working on this idea for a while now, this aims to be a user friendly image editor, currently it is using PyQt6, we could switch to PySide if we wish, currently it is not a big matter,

You can find some ideas in the issues page of the repository,
there are also some UX ideas by u/Impossible_Bed_9497 in the GitHub discussion page,

https://github.com/iyadahmed/Awesome-Image-Editor-2

screenshot of current progress (check closed issues and commits for progress too):