title: horizontal grid only (in python using pandas plot + pyplot)
body: <p>I would like to get only horizontal grid using pandas plot. </p>
  
  <p>The integrated parameter of pandas only has <code>grid=True</code> or <code>grid=False</code>, so I tried with matplotlib pyplot, changing the axes parameters, specifically with this code:</p>
  
  <pre><code>import pandas as pd
  import matplotlib.pyplot as plt
  fig = plt.figure()
  ax2 = plt.subplot()
  ax2.grid(axis='x')
  df.plot(kind='bar',ax=ax2, fontsize=10, sort_columns=True)
  plt.show(fig)
  </code></pre>
  
  <p>But I get no grid, neither horizontal nor vertical. Is Pandas overwriting the axes? Or am I doing something wrong?</p>