title: Matplotlib.pyplot.annotate() syntax error
body: <p>Trying to run this</p>
  
  <pre><code>t = np.arange(0.0, 5.0, 0.01) 
  s = np.cos(2*np.pi*t) 
  line, = plt.plot(t, s, lw=2) 
  plt.annotate('local max', xy=(2, 1), xytext=(3, 1.5),shrink=0.05),arrowprops=dict(facecolor='black', )
  plt.ylim(-2,2) 
  plt.show()
  </code></pre>
  
  <p>But got the following error:</p>
  
  <pre><code>    plt.annotate('local max', xy=(2, 1), xytext=(3, 1.5),shrink=0.05),arrowprops=dict(facecolor='black', )
      ^
  SyntaxError: cannot assign to function call
  </code></pre>
  
  <p>What's wrong with it? Thank you in advance!</p>