title: Conda: Changing Python Version. Unusual traceback
body: <p>Tried to change python version from 3.6 to 3.4 to use with tensorflow. I used the conda package manager. I typed</p>
  
  <pre><code>conda install python=3.4.0
  </code></pre>
  
  <p>When I tried to utilize ipython I got this weird traceback as I was typing my first import statement:</p>
  
  <pre><code>     File "C:\Program Files\Anaconda3\lib\site-packages\prompt_toolkit\interface.py", line 394, in run
      self.eventloop.run(self.input, self.create_eventloop_callbacks())
    File "C:\Program Files\Anaconda3\lib\site-packages\prompt_toolkit\eventloop\win32.py", line 87, in run
      self._process_queued_calls_from_executor()
    File "C:\Program Files\Anaconda3\lib\site-packages\prompt_toolkit\eventloop\win32.py", line 147, in _process_queued_calls_from_executor
      c()
    File "C:\Program Files\Anaconda3\lib\site-packages\prompt_toolkit\interface.py", line 326, in redraw
      self._redraw()
    File "C:\Program Files\Anaconda3\lib\site-packages\prompt_toolkit\interface.py", line 351, in _redraw
      self.renderer.render(self, self.layout, is_done=self.is_done)
    File "C:\Program Files\Anaconda3\lib\site-packages\prompt_toolkit\renderer.py", line 442, in render
      previous_width=(self._last_size.columns if self._last_size else 0))
    File "C:\Program Files\Anaconda3\lib\site-packages\prompt_toolkit\renderer.py", line 153, in _output_screen_diff
      current_pos = move_cursor(Point(y=y, x=c))
    File "C:\Program Files\Anaconda3\lib\site-packages\prompt_toolkit\renderer.py", line 90, in move_cursor
      _output_cursor_backward(current_x - new.x)
    File "C:\Program Files\Anaconda3\lib\site-packages\prompt_toolkit\terminal\win32_output.py", line 256, in cursor_backward
      self.cursor_forward(-amount)
    File "C:\Program Files\Anaconda3\lib\site-packages\prompt_toolkit\terminal\win32_output.py", line 249, in cursor_forward
      sr = self.get_win32_screen_buffer_info().dwCursorPosition
    File "C:\Program Files\Anaconda3\lib\site-packages\prompt_toolkit\terminal\win32_output.py", line 150, in get_win32_screen_buffer_info
      raise NoConsoleScreenBufferError
  prompt_toolkit.terminal.win32_output.NoConsoleScreenBufferError: No Windows console found. Are you running cmd.exe?
  
  During handling of the above exception, another exception occurred:
  
  Traceback (most recent call last):
    File "C:\Program Files\Anaconda3\Scripts\ipython-script.py", line 5, in &lt;module&gt;
      sys.exit(IPython.start_ipython())
    File "C:\Program Files\Anaconda3\lib\site-packages\IPython\__init__.py", line 119, in start_ipython
      return launch_new_instance(argv=argv, **kwargs)
    File "C:\Program Files\Anaconda3\lib\site-packages\traitlets\config\application.py", line 658, in launch_instance
      app.start()
    File "C:\Program Files\Anaconda3\lib\site-packages\IPython\terminal\ipapp.py", line 348, in start
      self.shell.mainloop()
    File "C:\Program Files\Anaconda3\lib\site-packages\IPython\terminal\interactiveshell.py", line 440, in mainloop
      self.interact()
    File "C:\Program Files\Anaconda3\lib\site-packages\IPython\terminal\interactiveshell.py", line 423, in interact
      code = self.prompt_for_code()
    File "C:\Program Files\Anaconda3\lib\site-packages\IPython\terminal\interactiveshell.py", line 333, in prompt_for_code
      pre_run=self.pre_prompt, reset_current_buffer=True)
    File "C:\Program Files\Anaconda3\lib\site-packages\prompt_toolkit\interface.py", line 404, in run
      self._redraw()
    File "C:\Program Files\Anaconda3\lib\site-packages\prompt_toolkit\interface.py", line 351, in _redraw
      self.renderer.render(self, self.layout, is_done=self.is_done)
    File "C:\Program Files\Anaconda3\lib\site-packages\prompt_toolkit\renderer.py", line 442, in render
      previous_width=(self._last_size.columns if self._last_size else 0))
    File "C:\Program Files\Anaconda3\lib\site-packages\prompt_toolkit\renderer.py", line 119, in _output_screen_diff
      current_pos = move_cursor(Point(0, 0))
    File "C:\Program Files\Anaconda3\lib\site-packages\prompt_toolkit\renderer.py", line 90, in move_cursor
      _output_cursor_backward(current_x - new.x)
    File "C:\Program Files\Anaconda3\lib\site-packages\prompt_toolkit\terminal\win32_output.py", line 256, in cursor_backward
      self.cursor_forward(-amount)
    File "C:\Program Files\Anaconda3\lib\site-packages\prompt_toolkit\terminal\win32_output.py", line 249, in cursor_forward
      sr = self.get_win32_screen_buffer_info().dwCursorPosition
    File "C:\Program Files\Anaconda3\lib\site-packages\prompt_toolkit\terminal\win32_output.py", line 150, in get_win32_screen_buffer_info
      raise NoConsoleScreenBufferError
  prompt_toolkit.terminal.win32_output.NoConsoleScreenBufferError: No Windows console found. Are you running cmd.exe?
  
  If you suspect this is an IPython bug, please report it at:
      https://github.com/ipython/ipython/issues
  or send an email to the mailing list at ipython-dev@scipy.org
  
  You can print a more detailed traceback right now with "%tb", or use "%debug"
  to interactively debug it.
  
  Extra-detailed tracebacks for bug-reporting purposes can be enabled via:
      %config Application.verbose_crash=True
  </code></pre>
  
  <p>Can't make heads or tails of it. Any help is appreciated. </p>