Bug summary

I have currently written a python script (call it detect.py) that checks to see if a new file has been added to a directory. If so, it calls another Python script (call it program.py) that takes the new file as input and uses matplotlib to plot graphs. However, instead of plotting and saving images, I get the resulting output:

Python[30970:2506101] *** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'NSWindow drag regions should only be invalidated on the Main Thread!'
*** First throw call stack:
(
0 CoreFoundation 0x00007fff4a758cf9 __exceptionPreprocess + 256
1 libobjc.A.dylib 0x00007fff752eda17 objc_exception_throw + 48
2 CoreFoundation 0x00007fff4a772859 -[NSException raise] + 9
3 AppKit 0x00007fff47da8e26 -[NSWindow(NSWindow_Theme) _postWindowNeedsToResetDragMarginsUnlessPostingDisabled] + 317
4 AppKit 0x00007fff47da6253 -[NSWindow _initContent:styleMask:backing:defer:contentView:] + 1479
5 AppKit 0x00007fff47da5c86 -[NSWindow initWithContentRect:styleMask:backing:defer:] + 45
6 _macosx.so 0x000000011640f200 -[Window initWithContentRect:styleMask:backing:defer:withManager:] + 80
7 _macosx.so 0x0000000116412747 FigureManager_init + 327
8 Python 0x000000010c5b1468 wrap_init + 12
9 Python 0x000000010c56acf5 PyObject_Call + 97
10 Python 0x000000010c5eabe8 PyEval_CallObjectWithKeywords + 159
11 Python 0x000000010c57afab wrapperdescr_call + 127
12 Python 0x000000010c56acf5 PyObject_Call + 97
.
.
.
61 Python 0x000000010c612aee pythread_wrapper + 25
62 libsystem_pthread.dylib 0x00007fff76d092eb _pthread_body + 126
63 libsystem_pthread.dylib 0x00007fff76d0c249 _pthread_start + 66
64 libsystem_pthread.dylib 0x00007fff76d0840d thread_start + 13
)
libc++abi.dylib: terminating with uncaught exception of type NSException
Abort trap: 6

From what I understand, Matplotlib is explicitly prone to multi-threading errors. Does this mean I cannot create an automated script for detecting new files and running a matplotlib analysis on the new files? O

Here is some additional information that I hope helps:

• Operating system: Mac OS Mojave (10.14.4)
• Matplotlib version: 2.2.4 (installed from pip)
• Python version: 2.7.16
• For automatic file detection, I used the watchdog library for python.