title: Opening a matplotlib pyplot in a tkinter canvas - import error
body: <p>I am trying to embed a pyplot in a tkinter canvas. I am using python 2.7 on Windows.</p>
  
  <p>I looked around for some example code and I found the following in the matplotlib documentation.</p>
  
  <pre><code>import matplotlib
  matplotlib.use('TkAgg')
  
  from numpy import arange, sin, pi
  from matplotlib.backends.backend_tkagg import FigureCanvasTkAgg, NavigationToolbar2TkAgg
  # implement the default mpl key bindings
  from matplotlib.backend_bases import key_press_handler
  
  
  from matplotlib.figure import Figure
  
  import sys
  if sys.version_info[0] &lt; 3:
      import Tkinter as Tk
  else:
      import tkinter as Tk
  
  root = Tk.Tk()
  root.wm_title("Embedding in TK")
  
  
  f = Figure(figsize=(5,4), dpi=100)
  a = f.add_subplot(111)
  t = arange(0.0,3.0,0.01)
  s = sin(2*pi*t)
  
  a.plot(t,s)
  
  
  # a tk.DrawingArea
  canvas = FigureCanvasTkAgg(f, master=root)
  canvas.show()
  canvas.get_tk_widget().pack(side=Tk.TOP, fill=Tk.BOTH, expand=1)
  
  toolbar = NavigationToolbar2TkAgg( canvas, root )
  toolbar.update()
  canvas._tkcanvas.pack(side=Tk.TOP, fill=Tk.BOTH, expand=1)
  
  def on_key_event(event):
      print('you pressed %s'%event.key)
      key_press_handler(event, canvas, toolbar)
  
  canvas.mpl_connect('key_press_event', on_key_event)
  
  def _quit():
      root.quit()     # stops mainloop
      root.destroy()  # this is necessary on Windows to prevent
                      # Fatal Python Error: PyEval_RestoreThread: NULL tstate
  
  button = Tk.Button(master=root, text='Quit', command=_quit)
  button.pack(side=Tk.BOTTOM)
  
  Tk.mainloop()
  # If you put root.destroy() here, it will cause an error if
  # the window is closed with the window manager.
  </code></pre>
  
  <p>However running this code gives me the following error:</p>
  
  <pre><code>from matplotlib.backends import _tkagg
  ImportError: cannot import name _tkagg
  </code></pre>
  
  <p>Does anyone know what the go is here? I've only found people asking about this on python 3 or on another OS.</p>