title: Python. Error using animation.FuncAnimation
body: <p>I am new to python, and I want to display the graph in a new window after clicking the button, but I don't know what is the error occur as I followed the documentation. I keep getting the same error as below.</p>
  
  <pre><code> Traceback (most recent call last):
    File "C:\Users\User\Desktop\IMPORTANT NOTES\python to firebase\GUI\increment.py", line 88, in &lt;module&gt;
      ani = animation.FuncAnimation(f, animate, interval=1000)
    File "C:\Users\User\AppData\Local\Programs\Python\Python35-32\lib\site-packages\matplotlib\animation.py", line 1462, in __init__
      TimedAnimation.__init__(self, fig, **kwargs)
    File "C:\Users\User\AppData\Local\Programs\Python\Python35-32\lib\site-packages\matplotlib\animation.py", line 1225, in __init__
      event_source = fig.canvas.new_timer()
  AttributeError: 'NoneType' object has no attribute 'new_timer'
  </code></pre>
  
  <p>Here is my code.</p>
  
  <pre><code>from tkinter import *
  import matplotlib
  matplotlib.use("TkAgg")
  from matplotlib.backends.backend_tkagg import FigureCanvasTkAgg,    NavigationToolbar2TkAgg
  from matplotlib.figure import Figure
  import matplotlib.animation as animation
  import matplotlib.pyplot as plt
  from matplotlib import style
  
  style.use("ggplot")
  
  f = Figure(figsize = (5,5), dpi = 100)
  a = f.add_subplot(111)
  #a.plot([1,2,3,4,5,6,7,8],[5,4,8,6,3,2,7,9])
  
  
  def animate(i):
      pullData = open ("sampleData.txt","r").read()
      datalist = pullData.split('\n')
      xList = []
      yList = []
      for eachLine in dataList:
          if len (eachLine)&gt;1:
              x,y=eachLine.split(',')
              xList.append(int (x))
              yList.append(int (y))
  
      a.clear()
      a.plot(xList,yList)
  
  
  
  class Application(Frame):
      """A GUI app with some buttons."""
  
      def __init__(self, master):
          """ Initialze frame"""
          Frame.__init__(self, master)
          self.grid()
          self.button_clicks=0 #count the number of button click
          self.create_widgets()
  
      def create_widgets(self):
          """Create button which displays number of clicks."""
  
          #Button1
          self.button1 = Button(self)
          self.button1 ["text"]="in"
          self.button1["command"] = self.update_news
          self.button1.grid()
  
  
  
      def update_news(self):
          toplevel = Toplevel()
  
  
  
          canvas = FigureCanvasTkAgg(f,toplevel)
          canvas.show()
          canvas.get_tk_widget().pack()
  
          toolbar = NavigationToolbar2TkAgg(canvas,toplevel)
          toolbar.update()
          canvas._tkcanvas.pack()
  
  
  #Building the window
  root = Tk()
  root.title("Buttons")
  root.geometry("200x300")
  
  app = Application(root)
  
  #MainLoop
  
  ani = animation.FuncAnimation(f, animate, interval=1000)
  root.mainloop()
  </code></pre>