I am running a stand-alone Python v3.2.2/Tkinter program on Windows, not calling any external libraries. Idle has been very helpful in reporting exceptions, and the program has been debugged to the point where none are reported. However, the python interpreter does occasionally crash at non-deterministic times - operations will run fine for a while and then suddenly hang. The crash triggers the standard Windows non-responding process dialog asking if I want to send a crash dump to Microsoft:
"pythonw.exe has encountered a problem and needs to close.
We are sorry for the inconvenience."
Crash reporting in Python says that the interpreter itself rarely crashes. My question is: no matter how many mistakes there are in a python script, is there any way it should in theory be able to crash the interpreter? Since there are no exceptions being reported and the crashes happen at random times, it's hard to narrow down. But if the interpreter is in theory supposed to be crash-proof, then something I'm doing is triggering a bug.
The code (a scrolling strip-chart demonstration) is posted at What is the best real time plotting widget for wxPython?. It has 3 buttons - Run, Stop, Reset. To cause a crash just press the buttons in random order for a minute or so. With no interaction, the demo will run forever without crashing.
Of course, the goal is for something like Python to never crash. Alas, we live in an imperfect world. A more useful question to ask, I think, is "What should I do if Python crashes?". If you want to help make a more perfect world, first make a quick search at the Python issue tracker to see if a similar problem has already been reported and possibly fixed in a newer or as yet unreleased version of Python. If not, see if you can find a way to reproduce the problem with clear directions about steps involved, what OS platform and version, what versions of Python and 3rd-party libraries, as applicable. Then open a new issue with all the details. Keep in mind that Python, like many open source projects, is an all-volunteer project so there can be no guarantee when or if the problem will be more deeply investigated or solved (most issues are resolved eventually) but you can be happy that you have done your part and likely saved someone (maybe many people) time and trouble. If you want other opinions before opening an issue, you could ask about it on the python-list mailing list/news group.
Python isn't indeed 100% crash proof, especially when you using external libraries, which TkInter is.
There is even page dedicated to it: http://wiki.python.org/moin/CrashingPython
Related
I have a PyQt application that occasionally will crash due to memory issues with the error shown below
The instruction at 0X00007FFC450FA07 reference memory at 0X0000000000000048. The memory could not be read.
I personally have not been able to reproduce this error in any way. It has happened on the computer's of a few people I work with while running my application. I have looked and see a lot of questions for languages like C# or C++, and it seems to be a pointer issue. Since I am using Python though, these questions and solutions are not very relevant since Python does not use pointers.
Seen here: C# example question the problem here is a long running thread. I do use threading in my application so I have been looking there. I have ran my application many times with the task manager open to monitor threads and have not seen any problems. All threads seem to close. If there is a better way to monitor this please let me know.
I am using PyCharm and my Python version is 3.9. I am also using Pyinstaller to create an executable version of the application. I have ran the program using the command line, launching the executable, and also directly through PyCharm and have not been able to see the error at all or debug it.
Is it possible this is happening due to bit related issues? Meaning that I am compiling my code using a 32-bit version of Python, could some computers have a problem with that? Would compiling with a 64 bit version possibly solve this?
At my work, there are a few python scripts that run automatically that no one really uses anymore. They are more of an annoyance than anything, but I don't want to have to delete it just in case we need it later.
My question is that if I go into the code and make everything into a comment, would that stop the code from running? Sorry if this is an obvious question, I have a beginner-intermediate knowledge of python and that seems like it would work without me having to delete the script, but I wanted to get some more opinions on this issue. I've only dealt with automatically running scripts a few times.
This is my first post on stack overflow so I hope I'm doing it properly.
I am currently working on a Terminal User Interface for python applications. I know that there are many ready-to-use libraries such as npyscreen out there, but I wantend to create one as programming excercice. In particular, I wanted to to play with some architectural patterns to learn them.
All that said, I'm currently facing several problems with python curses library, that I'm using as low level interface to the terminal.
The problems arise when I try to resize my terminal. As you can see from the code (see below), I handle the terminal resizing in the main loop, invoking the getmaxyx()() method of my curses window and redrawing what is on the screen accordingly.
The problem is that the screen seems to flicker when I try to resize the terminal.
Moreover, my "curses application" works fine on MacOS but totally crashes on windows (even after installing windows curses).
To handle that I tried to re-write the low-level interfice by using the blessed library. It solved the windows crashing problem, but the flickering still remains.
I can not figure out what the problem is.
Fore those wishing to help me, here follows the github page of the project: Terminal GUI on GitHub
Thank you in advance.
With curses, there's (at least) 3 things to look for:
ncurses can handle SIGWINCH (PDCurses may not)
some Python configurations interfere with ncurses receiving SIGWINCH. If your program never receives KEY_RESIZE (which it's not checking for...), then it's time to file a bug report for Python to get that fixed.
some programs don't actively read keyboard input (and if KEY_RESIZE isn't read, ncurses won't update the screensize. That would make the program crash.
My latest python debugging workflow appears extremely slow to me, and little satifying. How can I improve?
Setting: I work with some third-party python packages from github.
Workflow:
run into error after entering some command to the terminal (Ubuntu WSL, python 3.7)
read terminal error message output, most likely the first or last one is helpful
from the last message i take the code reference (ctrl+left mouse in vscode) and look at the code
i find some function call in the third party module that looks very unrelated to the problem
i add import pdb to the module, and a pdb.set_trace() before that function call
i run the program again, and it stops at the breakpoint
using n,r,u,d i try to navigate closer to the source of the error
i eventually find some error raise condition in some other module, where some property of a certain variable is checked. the variable itself is defined some levels up in the stack
re-running the program and stopping at the same breakpoint as before, i try to navigate to the point where the variable is set. I don't know on which level of the stack it is set, so i miss it sometimes. I set intermediate breakpoints to save me some work when re-running
i finally find the actual cause of the error. I can check out the workspace and eventually fix the error.
i go through all the modules and remove the import pdb and the pdb.set_trace
Thanks for any suggestions
are you using an IDE, not fully clear in your question?
they tend to have graphic ways of setting breakpoints and stepping,
and it saves the hassle of changing the source.
not going into ide opinions, but examples of ide's with debuggers are spyder, thonny and others.
you can also run the debugger via commandline to avoid changing source, but I don't think that's the way to go if you are looking to simplify the cognotive load.
Yes these things you have to do and in extra you can do include logging everywhere as applicable to get exact point where it got occurred.
I'm going to make this question as succinct and to the point as possible. I have a jupyter notebook that worked perfectly yesterday. Today, my windows 10 machine demanded an update and after updating, the jupyter notebook now cannot run. I can import libraries and define functions, but when I actually go about using the libraries and functions for computations, the [*] denoting python is busy never goes away, meaning the code is stuck (or is super slow). Even after 20 minutes the first code cell is not carried out. Yesterday, this notebook would run all 40 (roughly) cells in seconds. I have no idea why this happened, where to start trouble shooting from, or who to turn to for support. Has anyone else encountered this issue?
Windows: 10 (Version: 1607, OS Build: 14393)
Python: Anaconda (Python 3.5)
Architecture: 64 bit
Jupyter Notebook File + Resorces: https://github.com/diggetybo/ICA-Attachments
Maybe the windows update meant well, but it created a lot of upheaval on my system. I had to reconfigure a lot of settings ranging from privacy to monitor display resolution. I believe some registry entries are different, although I typically don't look registry entries on a day to day basis. Some registry switcharoo is my best guess as to why Python suffered from the update.
Good news is I got it functional again by reinstalling anaconda. It was a time consuming and desperate approach to the problem. At someone's leisure, any technical explanations as to why this might have occurred could still be worth posting. I'm hoping I won't have to do this every windows update.
I'd like to exempt myself from user error, but I'm not sure whether others have this problem or not. Please share any similar experiences in the comments.
Thanks for reading.