Hitting the acute accent ´ button on a Danish keyboard causes Python with tkinter to crash immediately. This is a problem because the key is just left of the backspace key.
Using:
Python 3.6.3
MacOS version of tkinter
ActiveTCL 8.6.4.1

MacBook-Pro:~ username$ python3 --version
Python 3.6.3
MacBook-Pro:~ username$ pip3 list
DEPRECATION: The default format will switch to columns in the future. You can use --format=(legacy|columns) (or define a format=(legacy|columns) in your pip.conf under the [list] section) to disable this warning.
altgraph (0.15)
future (0.16.0)
lxml (4.1.1)
macholib (1.9)
modulegraph (0.16)
pefile (2017.11.5)
pip (9.0.1)
py2app (0.14)
PyInstaller (3.4.dev0+ab8fd9753)
setuptools (28.8.0)
xmltodict (0.11.0)
MacBook-Pro:~ username$ python3 -c 'import tkinter; tkinter.Text().pack(); tkinter.mainloop()'
2018-01-02 11:31:53.488 Python[80562:5642430] *** Terminating app due to uncaught exception 'NSRangeException', reason: '-[__NSCFConstantString characterAtIndex:]: Range or index out of bounds'
*** First throw call stack:
(
	0   CoreFoundation                      0x000000010010e00b __exceptionPreprocess + 171
	1   libobjc.A.dylib                     0x0000000100de0c76 objc_exception_throw + 48
	2   CoreFoundation                      0x000000010019fc9d +[NSException raise:format:] + 205
	3   CoreFoundation                      0x0000000100089f26 -[__NSCFString characterAtIndex:] + 102
	4   Tk                                  0x0000000103ef1353 TkpInitKeymapInfo + 731
	5   Tk                                  0x0000000103ef71b1 Tk_MacOSXSetupTkNotifier + 798
	6   Tcl                                 0x0000000103dd1a50 Tcl_DoOneEvent + 300
	7   _tkinter.cpython-36m-darwin.so      0x0000000101fedaa1 _tkinter_tkapp_mainloop + 209
	8   Python                              0x00000001007bd7b8 _PyCFunction_FastCallDict + 552
	9   Python                              0x0000000100847164 call_function + 612
	10  Python                              0x0000000100848b74 _PyEval_EvalFrameDefault + 5604
	11  Python                              0x0000000100846e21 fast_function + 465
	12  Python                              0x000000010084714b call_function + 587
	13  Python                              0x0000000100848b74 _PyEval_EvalFrameDefault + 5604
	14  Python                              0x0000000100846500 _PyEval_EvalCodeWithName + 2720
	15  Python                              0x00000001008466a4 PyEval_EvalCode + 100
	16  Python                              0x0000000100883747 PyRun_StringFlags + 183
	17  Python                              0x00000001008837d1 PyRun_SimpleStringFlags + 65
	18  Python                              0x000000010089c304 Py_Main + 1812
	19  Python                              0x0000000100000dfe Python + 3582
	20  Python                              0x0000000100000c34 Python + 3124
	21  ???                                 0x0000000000000003 0x0 + 3
)
libc++abi.dylib: terminating with uncaught exception of type NSException
Abort trap: 6

This is a well-known bug with older versions of Tk on macOS.  Chances are that the Python 3.6.3 you are using is using the Apple-supplied version of Tk 8.5.x which exhibits this bug.  If you are using Python 3.6.3 downloaded from python.org, as documented in the installer readme and release notice, be aware that it links with Tk 8.5, not 8.6, so you will need to install a more recent version of ActiveTcl 8.5.  More details here: https://www.python.org/download/mac/tcltk/