Pyqt crashes without error. argv) class MainWindow(QtWidgets.
- Pyqt crashes without error. exec_(), stop. I imported the apt library outside that thread but could that be the reason? Hi, That's what I thought first but i don't think so looking at my code. PS: When I read a CSV file, it works. There are numerous ways to crash a PyQt / PySide application, many of which are extraordinarily difficult to debug, even with the proper tools. My idea (maybe wrong) is that all serialThread methods are executed on the same thread, also if I know that PyQt is not thread-safe and that a wrong handling of variables gives crashes of my type, but I can’t understand what is wrong with my code. QtCore import * from PyQt5. 7 and PyQt4. Recently I wrote a fairly extensive experimental physics measurement control GUI in PyQt4 (python 2. My idea (maybe wrong) is that all serialThread methods are executed on the same thread, also if I'm practicing a program that reads and displays Excel files Try raising the entire code. I am using the following code to start an close the application: While debug any PyQt5 program using Pycharm 4. You can get the instance with . TemporaryFile()(with better formatting hopefully) at the very beginning of the execution of your program, then all the prints will be redirected to a temporary file, which will be deleted when your program exits. exec() function of the app returns the exit code, so you can wrap this with sys. exe process. Even I give to other variable first it still not work. dll". After you click the + at the left of self, it shows 'Collecting data': And then crash the Python. QAxContainer import QAxWidget app = None if __name__ == "__main__": app = QApplication(sys. Initially, it shows the self variable just fine. a button. I have attempted to convert my python program into a . instance(). argv) class MainWindow(QtWidgets. exec_(). While playing around with different ways to show a webcam feed (obtained using imageio/ffmpeg) in a PyQt4 window, I stumbled upon this answer. width(), qimage. height() qimage = qimage. show() self. Code is a more structured rewrite of a program that was existing and running before. quit() inside any of the event handlers. Basically, this software programs an mikrocontroller, tests if pcb components are working You are quite a bit ahead of me with PyQt, but I had a similar problem of crashes with no errors to see. However, even then it feels like you are doing too much to create your own window subclassing "object". QMainWindow): def . And to a large extent it does - but doing more would entail a significant performance cost that would affect all PyQt code, so a compromise must be I've a PyQt code which keeps on crashes giving me error message QPixmap::fromImage: QPixmap cannot be created without a QGuiApplication QPixmap: Must construct a Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand; OverflowAI GenAI features for Teams; OverflowAPI Train & fine-tune LLMs; Labs The future of collective knowledge sharing; About the company Visit the blog exit is a static method of QCoreApplication and quit is a "static slot" (not sure what the difference is) of QCoreApplication. If I close the window, Thanks to @ekhumoro, I'm posting the response that worked here in case anyone else has this issue. The actual code runs fine through IDLE, but everytime I try and run the newly converted . B When I run the code by itself, it works just fine. exe path/to/script. One should start running as soon as the GUI is loaded and another one should start later by some signal. First answer is a lot of words about nothing. QApplication(sys. 3, it crashes the Python. (Sherlock Holmes) You can place something like import sys; import tempfile; sys. The documentation provided herein is licensed @JonB Thanks for your reply @JonB said in PyQt6 program randomly crashing without any error, falling into despair:. Once the application loop has started, when an exception is raised, the whole program just exits without displaying the error message. stdout = tempfile. If you can reduce your program to the minimum number of lines needed to reproduce the problem, and post it, we might be able to say something. However, as you observe it does not do that if I go python3 and then paste the same lines in. 04 and it does a Segmentation fault (core dumped) without putting up a dialog. The setup The QDialog is behaving as expected, since I've been able to confirm the test print is executed upon the QDialog returning Accepted, but the application will completely crash, Let’s walk through an example of how an innocuous callback creates a race condition. QtWidgets import QApplication, QWidget, The following minimal code crashes in the QThread's run for loop. (Sherlock Holmes) Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand; OverflowAI GenAI features for Teams; OverflowAPI Train & fine-tune LLMs; Labs The future of collective knowledge sharing; About the company Visit the blog I can be the garbage collector that dispose your app. I agree this seems brain-damaged :) The only difference is that python3 has a stdin While debug any PyQt5 program using Pycharm 4. . @Donald-Duck I just tried it under Ubuntu 20. (Sherlock Holmes) I would like to have 2 worker threads in my application. Let's say it's a button click. I agree this seems brain-damaged :) The only difference is that python3 has a stdin @Donald-Duck I just tried it under Ubuntu 20. For a more long-term solution I'd After closing the app the user should be able to do further work with the variables in the console. QtWidgets import * class It is an old maxim of mine that when you have excluded the impossible, whatever remains, however improbable, must be the truth. But by closing the Gui the Kernel crashes and it is not possible to make any new input to the console. copy(0, 0, qimage. I've been programming an application with PyQt5, and when I try to open a new window after a button interaction, the program crashes, and spits out exit code -1073740791. This question is unlikely to help any future visitors; it is only relevant to a small geographic area, a specific moment in time, or an extraordinarily narrow situation that is not generally applicable to the worldwide audience of the internet. app, it closes straight away. Secondly, message_box is local to show_message meaning that when message_box finishes, show_message is destroyed. 9, Pycharm, PyQt5 - 5. Hi, That's what I thought first but i don't think so looking at my code. My pyqt application is not behaving as expected. Documentation contributions included herein are the copyrights of their respective owners. (Sherlock Holmes) Importing QtWebEngineWidgets itself doesn't cause a crash unless I try to create an application. The Application window opens but as soon as I click on the button, the window crashes. In the "list of all members including inherited" for QApplication it includes exit (which obviously links to the QCoreApplication doc page), but doesn't include quit. First, you are trying to run a second instance of QApplication in show_message which is what's causing the crash. py file from the terminal and @Thombou said in [pyqt] Slot crashed in secondary thread without error and works in GUI thread: I instantiate an object of a class that has been defined in the main When you are developing a pyqt gui application, you may encounter this kind of problem: The gui application crashed suddenly, however, there is no any error message is Hello, I have a program that collects MODBUS serial data as a list in a QThread, and emits it to a PyQT5 GUI thread that processes the data then uses it to update GUI elements. If you run your program without or even with IDLE In the sections below, you’ll learn how to use PyQt’s built-in thread support to solve the issue of unresponsive or frozen GUIs and provide the best possible user experience in your applications. 15. width() ht = qimage. Now I implemented all communication btw PyQt objects in the signal/slot system, but the crashes remain. py and also for python3 < script. exe immediately, printing: In addition to the previous answer, not every time when all windows are closed does the GUI event loop, run by app. After implementing this in Python 2. shape[1]*2 sorry, I read through the QImage API, but I don;t get why I need to add The following minimal code crashes in the QThread's run for loop. UI just dissapears, program shutdown. I imported the apt library outside that thread but could that be the reason? I'm trying to launch the following code. How do I want to show on a QImage and translate to QPixmap, but when I want to manipulate (copy, scaled, or construct by QPixmap) qimage then the process will crash. The crash is a "hard" crash: it's not a Python exception, but a Windows popup saying "Python has stopped working". Quite often, the IDE or debugger itself can be the cause of the problem, or may mask error messages comming either from Python or from underlying libraries, such as Qt). Are we just to assume these static I know that PyQt is not thread-safe and that a wrong handling of variables gives crashes of my type, but I can't understand what is wrong with my code. It does that for python3 script. quit(). What does "button handling" mean? Assuming "main worker thread" means "a thread which is not the "main thread -> GUI" ", are you aware that no secondary thread is allowed to access any UI stuff, e. Try in this way: from PyQt4. But the application crashes after 10sec - 2 minutes. In minimal examples, it works flawlessly, but once I add many GUI elements it becomes unstable, sometimes crashing in seconds or minutes, sometimes running fine for hours-- Pycharm shows no traceback, but with terminal execution, failure prints this: Oh, weird, I never had this issue, I edit my answer with a small example on how to manage a popup with different buttons (and also popup with just one button) if it can help, and you can try this example actually works for you, also, from what I've see, a thing that can cause exception is not having created a QApplication when using QMessageBox. QtWidgets import * class Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand; OverflowAI GenAI features for Teams; OverflowAPI Train & fine-tune LLMs; Labs The future of collective knowledge sharing; About the company You situation sounds unusual, but you give too little information to say more. argv) while True: # run some codes that use QAxWidget. If you want to terminate it manually you can use app. I'm running this on Windows 7. One way around this is to create the message box outside the function and supply it as an As eyllanesc says it is probably because you have not imported QMainWindow before using it. It stops GUI event loop and launches your code after app. exe immediately, printing: @KroMignon said in PyQt QImage cna't copy, crash without error code: arr. I agree this seems brain-damaged :) The only difference is that python3 has a stdin It is an old maxim of mine that when you have excluded the impossible, whatever remains, however improbable, must be the truth. Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand; OverflowAI GenAI features for Teams; OverflowAPI Train & fine-tune LLMs; Labs The future of collective knowledge sharing; About the company This affects both C++ and Python, so you must pay attention to it. I imported the apt library outside that thread but could that be the reason? @JonB Thanks for your reply @JonB said in PyQt6 program randomly crashing without any error, falling into despair:. g. Start button runs some calculations in the background (by starting update function) and thanks to threading I can still use UI. py it crashes on line 5 with the exit code -1073741819 without throwing any Python error. I found that in those cases I just run the . This works when removing the widget object. height()) then it crash. stderr = tempfile. The problem is with the OED file. I'm using I developed my first bigger application with PyQt6 for my companies production line. I'm working with Python 2. So try putting the app global. app using PyInstaller. I'll add a few prints and the code. import sys from qtpy import QtWidgets from src. I wrote simple program which has pyQt interface with 2 buttons (start and cancel). But If I The handling of errors in widget callbacks, including where it sends any error messages, is done by the GUI framework. However, sometimes the whole application may crash and terminate: this is called a segmentation fault (segfault) on Unix operating systems and this is due to the fact that graphical user interfaces of Spyder are handled by PyQt (or PySide), the Python bindings for Qt. ui. copy(0, 0, wt, ht) @Donald-Duck I just tried it under Ubuntu 20. I c Hi, That's what I thought first but i don't think so looking at my code. (Sherlock Holmes) Understand PyQT QHBoxLayout addStretch() with Examples for Beginners – PyQT Tutorial; PyQT Add and Show a Table: A Beginner Guide – PyQT Tutorial; Set PyQT Table Header Text Align Left, Center and Right: A Beginner Guide – PyQT Tutorial; What is Horizontal Header and Vertical Header in PyQT Table, How to Change and Hidden Them – PyQT There are two main issues with your code. It is an old maxim of mine that when you have excluded the impossible, whatever remains, however improbable, must be the truth. This prevents me For the (then unrelated) problem of the crashes: They don't happen on exit, program runs fine on at least my linux, but not on windows. (Sherlock Holmes) It is an old maxim of mine that when you have excluded the impossible, whatever remains, however improbable, must be the truth. The QApp is a singleton. And yet both seem to work as per your code. qimage. exit to get the right exit code. My code looks like this: c I have attempted to convert my python program into a . mainwindow import Ui_MainWindow from src. In the code for win2: def closeWindow(self): self. parent(). B You can place something like import sys; import tempfile; sys. py. TemporaryFile(); sys. 0. Code: 1- The update of the plotting area © 2022 The Qt Company Ltd. Also the . close() You'll want to use QApplication. QtWidgets import QApplication, QWidget, @JonB It won't crash!But when I change to. Run_OMD_Process import run_omd app = QtWidgets. I'm using Python 3. dynamicCall() function # print some results sleep(30) I'm practicing a program that reads and displays Excel files Try raising the entire code. 7 import sys from PyQt5. Other file plotted in the pyqt window Only the plot in a separated area. I’ve written this using PyQt for readability and reproducibility, but the principles apply The issue seems to be that Qt crashes internally but in a way that causes the application to end abruptly also circumventing my try / except on Exception. 7) but I am experiencing frequent crashes without any error messages. (Sherlock Holmes) @JonB Thanks for your reply @JonB said in PyQt6 program randomly crashing without any error, falling into despair:. For a more long-term solution I'd It is an old maxim of mine that when you have excluded the impossible, whatever remains, however improbable, must be the truth. wt = qimage. import sys import time from PyQt5. But when I try to incorporate it to a pyqt window, it crashes. I would like to know: what are But when I run it from the command line using python. The info says that the crash is in "atio6axx. The only non self variable I am using are locals to the function. critical. 7 as an ImageDisplayWidget class (as summarized below), everything seems to work just fine: A window opens, showing my webcam feed without a glitch. I suppose most Python coders will find managing memory in this way quite foreign, and they might expect PyQt to do it all for them.