title: Python crashes when importing matplotlib.pyplot
body: <p>I am trying to import pyplot from matplotlib using:
  <code>import matplotlib.pyplot as plt</code></p>
  
  <p>and i receive the following error which terminates my python program. </p>
  
  <p>My code was recently working on my old MacBook Pro 2012 running El Capitan. I am now running on a 2017 Macbook Pro with High Sierra... don't know if this has anything to do with it. I tried uninstalling and reinstalling Matplotlib using pip but still get the same issue. I'm using anaconda installation of Python. Help is appreciated!</p>
  
  <pre><code>2017-10-31 00:05:27.991 python[69256:37459662] -[TKWindow setCanCycle:]: unrecognized selector sent to instance 0x1030d41a0
  2017-10-31 00:05:28.000 python[69256:37459662] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[TKWindow setCanCycle:]: unrecognized selector sent to instance 0x1030d41a0'
  *** First throw call stack:
  (
      0   CoreFoundation                      0x00007fff2aedb0fb __exceptionPreprocess + 171
      1   libobjc.A.dylib                     0x00007fff517c9c76 objc_exception_throw + 48
      2   CoreFoundation                      0x00007fff2af73c34 -[NSObject(NSObject) doesNotRecognizeSelector:] + 132
      3   CoreFoundation                      0x00007fff2ae51510 ___forwarding___ + 1456
      4   CoreFoundation                      0x00007fff2ae50ed8 _CF_forwarding_prep_0 + 120
      5   libtk8.5.dylib                      0x00000001079eff9f ApplyWindowAttributeFlagChanges + 1124
      6   libtk8.5.dylib                      0x00000001079f0aa8 TkMacOSXApplyWindowAttributes + 51
      7   libtk8.5.dylib                      0x00000001079f0f86 TkMacOSXMakeRealWindowExist + 1189
      8   libtk8.5.dylib                      0x00000001079f112a TkWmMapWindow + 52
      9   libtk8.5.dylib                      0x000000010795a918 Tk_MapWindow + 65
      10  libtk8.5.dylib                      0x0000000107963469 MapFrame + 62
      11  libtcl8.5.dylib                     0x00000001078c0178 TclServiceIdle + 76
      12  libtcl8.5.dylib                     0x00000001078a5491 Tcl_DoOneEvent + 329
      13  _tkinter.so                         0x00000001063ea573 EventHook + 195
      14  gnureadline.so                      0x0000000104deb4ec call_readline + 364
      15  libpython2.7.dylib                  0x0000000100009000 PyOS_Readline + 256
      16  libpython2.7.dylib                  0x00000001000b8b55 builtin_raw_input + 597
      17  libpython2.7.dylib                  0x00000001000c3d7d PyEval_EvalFrameEx + 24989
      18  libpython2.7.dylib                  0x00000001000c6063 PyEval_EvalCodeEx + 2115
      19  libpython2.7.dylib                  0x00000001000c40d0 PyEval_EvalFrameEx + 25840
      20  libpython2.7.dylib                  0x00000001000c6063 PyEval_EvalCodeEx + 2115
      21  libpython2.7.dylib                  0x00000001000c40d0 PyEval_EvalFrameEx + 25840
      22  libpython2.7.dylib                  0x00000001000c6063 PyEval_EvalCodeEx + 2115
      23  libpython2.7.dylib                  0x00000001000c40d0 PyEval_EvalFrameEx + 25840
      24  libpython2.7.dylib                  0x00000001000c6063 PyEval_EvalCodeEx + 2115
      25  libpython2.7.dylib                  0x00000001000c40d0 PyEval_EvalFrameEx + 25840
      26  libpython2.7.dylib                  0x00000001000c6063 PyEval_EvalCodeEx + 2115
      27  libpython2.7.dylib                  0x000000010003e4d0 function_call + 176
      28  libpython2.7.dylib                  0x000000010000cab2 PyObject_Call + 98
      29  libpython2.7.dylib                  0x00000001000bedca PyEval_EvalFrameEx + 4586
      30  libpython2.7.dylib                  0x00000001000c6063 PyEval_EvalCodeEx + 2115
      31  libpython2.7.dylib                  0x00000001000c40d0 PyEval_EvalFrameEx + 25840
      32  libpython2.7.dylib                  0x00000001000c6063 PyEval_EvalCodeEx + 2115
      33  libpython2.7.dylib                  0x00000001000c6186 PyEval_EvalCode + 54
      34  libpython2.7.dylib                  0x00000001000eb43e PyRun_FileExFlags + 174
      35  libpython2.7.dylib                  0x00000001000eb6da PyRun_SimpleFileExFlags + 458
      36  libpython2.7.dylib                  0x000000010010272d Py_Main + 3165
      37  python                              0x0000000100000f54 start + 52
      38  ???                                 0x0000000000000002 0x0 + 2
  )
  libc++abi.dylib: terminating with uncaught exception of type NSException
  Abort trap: 6
  </code></pre>
  
  <p>Edit:
  When I change the backend of Matplotlib to 'Agg' instead of 'TkAgg' I do not get the error above and the program runs but the figures do not display.</p>