Show function triggering unwanted output

1

Whenever I use the matplotlib.pyplot.show function in a Python program, it results in output such as below while the program runs correctly otherwise:

1   HIToolbox                           0x00007ff81116c0c2 _ZN15MenuBarInstance22RemoveAutoShowObserverEv + 30
2   HIToolbox                           0x00007ff8111837e3 SetMenuBarObscured + 115
3   HIToolbox                           0x00007ff81118a29e _ZN13HIApplication11FrontUILostEv + 34
4   HIToolbox                           0x00007ff811183622 _ZN13HIApplication15HandleActivatedEP14OpaqueEventRefhP15OpaqueWindowPtrh + 508
5   HIToolbox                           0x00007ff81117d950 _ZN13HIApplication13EventObserverEjP14OpaqueEventRefPv + 182
6   HIToolbox                           0x00007ff811145bd2 _NotifyEventLoopObservers + 153
7   HIToolbox                           0x00007ff81117d3e6 AcquireEventFromQueue + 494
8   HIToolbox                           0x00007ff81116c5a4 ReceiveNextEventCommon + 725
9   HIToolbox                           0x00007ff81116c2b3 _BlockUntilNextEventMatchingListInModeWithFilter + 70
10  AppKit                              0x00007ff80a973f33 _DPSNextEvent + 909
11  AppKit                              0x00007ff80a972db4 -[NSApplication(NSEvent) _nextEventMatchingEventMask:untilDate:inMode:dequeue:] + 1219
12  AppKit                              0x00007ff80a9653f7 -[NSApplication run] + 586
13  _macosx.cpython-310-darwin.so       0x0000000110407e22 show + 162
14  Python                              0x0000000100bb7595 cfunction_vectorcall_NOARGS + 101
15  Python                              0x0000000100c9101f call_function + 175
16  Python                              0x0000000100c8a2c4 _PyEval_EvalFrameDefault + 34676
17  Python                              0x0000000100c801df _PyEval_Vector + 383
18  Python                              0x0000000100c9101f call_function + 175
19  Python                              0x0000000100c8a2c4 _PyEval_EvalFrameDefault + 34676
20  Python                              0x0000000100c801df _PyEval_Vector + 383
21  Python                              0x0000000100b53f61 method_vectorcall + 481
22  Python                              0x0000000100c8a4f2 _PyEval_EvalFrameDefault + 35234
23  Python                              0x0000000100c801df _PyEval_Vector + 383
24  Python                              0x0000000100c9101f call_function + 175
25  Python                              0x0000000100c8a2c4 _PyEval_EvalFrameDefault + 34676
26  Python                              0x0000000100c801df _PyEval_Vector + 383
27  Python                              0x0000000100cf536d pyrun_file + 333
28  Python                              0x0000000100cf4b2d _PyRun_SimpleFileObject + 365
29  Python                              0x0000000100cf417f _PyRun_AnyFileObject + 143
30  Python                              0x0000000100d20047 pymain_run_file_obj + 199
31  Python                              0x0000000100d1f815 pymain_run_file + 85
32  Python                              0x0000000100d1ef9e pymain_run_python + 334
33  Python                              0x0000000100d1ee07 Py_RunMain + 23
34  Python                              0x0000000100d201e2 pymain_main + 50
35  Python                              0x0000000100d2048a Py_BytesMain + 42
36  dyld                                0x00007ff80741b310 start + 2432

This happens even when the program is as simple as the following:

import matplotlib.pyplot as plt

x = [1, 2, 3]
y = [1, 2, 3]
plt.plot(x, y)

plt.show()

Other than the unwanted output, this or any other program with the matplotlib.pyplot.show function appears to run correctly, including the graph displays triggered by the show function. If I remove plt.show() from the code above or any of the other programs, the unwanted output does not come out but then the graph is also not displayed.

I have Matplotlib 3.5.2 and Python v3.10.4 installed along with macOS Venture v13.1 on my Mac. I get this unwanted output when I use macOS’s command line interface to run the above program or any of the others with the matplotlib.pyplot.show function (assume the program’s name is test.py):

python3 test.py

I get the unwanted output when I also use Visual Studio Code v1.74.2 to run the program but not if I use IDLE, Python’s Integrated Development and Learning Environment, or run the code in it from within a Jupyter notebook.

I can remove the show function from my Python programs to avoid the unwanted output but then the charts will not appear and I would prefer using the show function rather than a makeshift solution.

My questions are:

  1. Why do I get this output even though there is nothing in the above code that would normally trigger it?
  2. How is this output helpful, if any, and, if so, how can it be used if needed?
  3. How can I prevent it from coming out after using the show function?
2

This seems to be a macOS issue.

Here’s an example of it occurring with Python and Tk (instead of the Matplotlib macosx backend):

And here’s an example of it in mpv:

Both point to it occurring after recent macOS updates.

1 Like
3

I was able to better isolate this problem after making further enquiries. I have found out that the mentioned unwanted output comes out only when the “Automatically hide and show the menu bar” option under Systems Settings->Desktop&Dock->Menu Bar is set to Always (which is my setting) or on Desktop Only in macOS Ventura 13.1. The unwanted output does not come out if that option is set to In Full Screen Only or Never.

According to the respective Matplotlib and Python/CPython developers on GitHub, the underlying problem appears to be a bug in macOS Ventura 13.1, as @quantum.analyst hinted in his reply. I was also told that a Feedback Assistant report had been submitted to Apple about the identified bug in macOS Ventura 13.1 upon review of the issue report I submitted towards Python/CPython GitHub repository. Hopefully, this bug will have been taken care of in one of the future versions of macOS Ventura.