title: show grid by default
body: <p>I am using the matplotlib.pyplot package in a Jupyter Notebook and for each separate plot I am turning on the grid:</p>
  <pre class="lang-py prettyprint-override"><code>import matplotlib.pyplot as plt
  
  plt.plot(x, y)
  plt.grid()
  </code></pre>
  <p>Is there a way to show the grid by default, throughout the whole Notebook?</p>