title: Matplotlib basemap multiple shapes animation exception: 'list' object has no attribute 'set_animated'
body: <p>I'm using basemap to plot some polygons on a map and make an animation. When I animate one polygon and change its shape it works.
  If I add second one I got exception:</p>
  
  <pre><code>Traceback (most recent call last):
    File "...\Programs\Python\Python37\lib\site-packages\matplotlib\cbook\__init__.py", line 216, in process
      func(*args, **kwargs)
    File "...\Local\Programs\Python\Python37\lib\site-packages\matplotlib\animation.py", line 953, in _start
      self._init_draw()
    File "...\Local\Programs\Python\Python37\lib\site-packages\matplotlib\animation.py", line 1741, in _init_draw
      a.set_animated(self._blit)
  AttributeError: 'list' object has no attribute 'set_animated'
  Traceback (most recent call last):
    File "...\Local\Programs\Python\Python37\lib\site-packages\matplotlib\cbook\__init__.py", line 216, in process
      func(*args, **kwargs)
    File "...\Local\Programs\Python\Python37\lib\site-packages\matplotlib\animation.py", line 1269, in _handle_resize
      self._init_draw()
    File "..\Local\Programs\Python\Python37\lib\site-packages\matplotlib\animation.py", line 1741, in _init_draw
      a.set_animated(self._blit)
  AttributeError: 'list' object has no attribute 'set_animated'
  </code></pre>
  
  <p>My code:</p>
  
  <pre class="lang-py prettyprint-override"><code>input = pd.read_csv(filename)
  data = pd.read_csv(datafilename)
  
  
  m = Basemap(projection='spstere',boundinglat=-50,lon_0=0,resolution='l', area_thresh = 1000.0)
  m.fillcontinents()
  m.drawmapboundary()
  lon =[]
  lat = []
  lon1=[]
  lat1=[]
  for j in range(0,100):
      latlist = list()
      latlist1 = list()
      for i in range(0,361):
          latlist.append(float(input.iloc[j][str(i)]))
          latlist1.append(float(data.iloc[j][str(i)]))
      lat.append(latlist)
      lon.append(list(range(0,361)))
      lat1.append(latlist1)
      lon1.append(list(range(0,361)))
  polys = []
  
  x,y = m(lon[0],lat[0])
  xy = list(zip(x,y))
  poly=Polygon(xy,facecolor='None', alpha=1, edgecolor='green', linewidth=1)
  
  x1,y1 = m(lon1[0],lat1[0])
  xy1 = list(zip(x1,y1))
  poly1=Polygon(xy1,facecolor='None', alpha=1, edgecolor='red', linewidth=1)
  
  polys.append(poly)
  polys.append(poly1)
  def init():
      plt.gca().add_patch(polys[0])
      plt.gca().add_patch(polys[1])
      return polys,
  
  def animate(i):
      print(i)
      x,y = m(lon[i], lat[i])
      xy=list(zip(x,y))
      polys[0].set_xy(xy)
  
      x1,y1 = m(lon1[i], lat1[i])
      xy1=list(zip(x1,y1))
      polys[1].set_xy(xy1)
      return polys,
  
  anim = animation.FuncAnimation(plt.gcf(), animate, init_func=init, frames=100, interval=500, blit=True)
  
  plt.show()
  </code></pre>
  
  <p>If I return only one poly in functions and set blit=False it works. 
  If I return only one poly in functions and blit=True - only one polygon changes. How to animate two shapes in one animation with blitting?</p>