title: Python: Plot a bar graph for a pandas data frame with x axis using a given column
body: <p>I want to plot a bar chart for the following pandas data frame on Jupyter Notebook. </p>
  
  <pre><code>      | Month | number
  -------------------------
      0 | Apr   |  6.5
      1 | May   |  7.3
      2 | Jun   |  3.9
      3 | Jul   |  5.1
      4 | Aug   |  4.1
  </code></pre>
  
  <p>I did:</p>
  
  <pre><code>%matplotlib notebook
  import matplotlib.pyplot as plt
  import matplotlib
  matplotlib.style.use('ggplot')
  trend_df.plot(kind='bar')
  </code></pre>
  
  <p>How do I make sure x-axis is actually showing month here?</p>