Weird interaction with Tkinter

[rdwmpls]

Bug report

Bug summary

Importing matplotlib before creating a Tk instance causes a crash.

Code for reproduction
Bad:

import Tkinter as tk
import matplotlib.pyplot as plt
root = tk.Tk()

Ok:

import Tkinter as tk
root = tk.Tk()
import matplotlib.pyplot as plt

Actual outcome

ron ~ $ python
Python 2.7.14 |Anaconda custom (64-bit)| (default, Oct  5 2017, 02:28:52) 
[GCC 4.2.1 Compatible Clang 4.0.1 (tags/RELEASE_401/final)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import Tkinter as tk
>>> import matplotlib.pyplot as plt
>>> root = tk.Tk()
2018-01-12 16:11:38.882 python[3561:147192] -[NSApplication _setup:]: unrecognized selector sent to instance 0x7fe13ec690e0
2018-01-12 16:11:38.883 python[3561:147192] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[NSApplication _setup:]: unrecognized selector sent to instance 0x7fe13ec690e0'
*** First throw call stack:
(
	0   CoreFoundation                      0x00007fff4533e1fb __exceptionPreprocess + 171
	1   libobjc.A.dylib                     0x00007fff6bfbf942 objc_exception_throw + 48
	2   CoreFoundation                      0x00007fff453d5714 -[NSObject(NSObject) doesNotRecognizeSelector:] + 132
	3   CoreFoundation                      0x00007fff452b5b53 ___forwarding___ + 1443
	4   CoreFoundation                      0x00007fff452b5528 _CF_forwarding_prep_0 + 120
	5   libtk8.6.dylib                      0x000000010400146f TkpInit + 383
	6   libtk8.6.dylib                      0x0000000103f5a21e Initialize + 2622
	7   _tkinter.so                         0x0000000103d81be4 Tcl_AppInit + 84
	8   _tkinter.so                         0x0000000103d81448 Tkinter_Create + 1128
	9   libpython2.7.dylib                  0x000000010394f8f4 PyEval_EvalFrameEx + 22980
	10  libpython2.7.dylib                  0x0000000103949cd4 PyEval_EvalCodeEx + 2164
	11  libpython2.7.dylib                  0x00000001038cbbb3 function_call + 355
	12  libpython2.7.dylib                  0x00000001038a34d5 PyObject_Call + 101
	13  libpython2.7.dylib                  0x00000001038b2642 instancemethod_call + 162
	14  libpython2.7.dylib                  0x00000001038a34d5 PyObject_Call + 101
	15  libpython2.7.dylib                  0x0000000103953a2f PyEval_CallObjectWithKeywords + 159
	16  libpython2.7.dylib                  0x00000001038b05d4 PyInstance_New + 148
	17  libpython2.7.dylib                  0x00000001038a34d5 PyObject_Call + 101
	18  libpython2.7.dylib                  0x000000010394f578 PyEval_EvalFrameEx + 22088
	19  libpython2.7.dylib                  0x0000000103949cd4 PyEval_EvalCodeEx + 2164
	20  libpython2.7.dylib                  0x0000000103949452 PyEval_EvalCode + 34
	21  libpython2.7.dylib                  0x0000000103976ba1 PyRun_InteractiveOneFlags + 385
	22  libpython2.7.dylib                  0x000000010397659e PyRun_InteractiveLoopFlags + 110
	23  libpython2.7.dylib                  0x0000000103976450 PyRun_AnyFileExFlags + 64
	24  libpython2.7.dylib                  0x000000010398d572 Py_Main + 3506
	25  libdyld.dylib                       0x00007fff6cbac115 start + 1
	26  ???                                 0x0000000000000001 0x0 + 1
)
libc++abi.dylib: terminating with uncaught exception of type NSException

Expected outcome

Too obvious to need to describe.

Matplotlib version

• Operating system: macOS High Sierra (version 10.13.2)
• Matplotlib version: 2.1.0
• Matplotlib backend: MacOSX
• Python version: Python 2.7.14 |Anaconda custom (64-bit)| (default, Oct 5 2017, 02:28:52)
• Jupyter version (if applicable): N/A
• Other libraries: N/A

[tacaswell]

I am not surprised if there are issues as you are trying to run two different GUI frameworks. If you do matplotlib.use('tkagg') before importing pyplot does this issue go away?

[rudrathegreat]

The link below gives really good code on how to combine matplotlib and tkinter -

https://pythonprogramming.net/how-to-embed-matplotlib-graph-tkinter-gui/

And what @tacaswell is saying is right. That line is the backend for matplotlib which gives it the functionality to work together with tkinter

[QuLogic]

I'm going to close this as it's been 10 months without a response from the reporter. Please comment if there is still an issue.

[jwbrown]

Using matplotlib.use('tkagg')
worked for me... took a while to find this post though, but thanks