title: FuncAnimation produces one more frame than intended at startup
body: <p><a href="https://i.stack.imgur.com/17C3Z.gif" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/17C3Z.gif" alt="enter image description here" /></a></p>
  <p>Watch closely as the GUI starts up. The first iteration appears to be doubling for some reason. I have the frames parameter set to 4 (equivalent to range(4)), so we should only see four points, but we have 5. Here is the code:</p>
  <pre><code>import matplotlib.pyplot as plt
  from matplotlib.animation import FuncAnimation
  import random
  
  
  def animate(_):
      x = random.uniform(0, 10)
      y = random.uniform(0, 10)
  
      plt.scatter(x, y, color='maroon', marker='x')
  
  
  plt.xlim((0, 10))
  plt.ylim((0, 10))
  ani = FuncAnimation(plt.gcf(), animate, frames=4, interval=1000, repeat=False)
  plt.show()
  </code></pre>
  <p>How can this be fixed?</p>