title: How to plot Time Series using matplotlib Python
body: <p>I want to visualize these data:<br>
  Data Source : <a href="http://pastebin.com/vx9xLtdm" rel="nofollow">http://pastebin.com/vx9xLtdm</a></p>
  
  <p>I couldn't group data per days.</p>
  
  <pre><code>import matplotlib.pyplot as plt
  import numpy as np
  import pandas as pd
  
  df = pd.read_csv('sample.csv')
  </code></pre>
  
  <p>I tried the both</p>
  
  <pre><code>x = df.groupby(lambda x: x.created_date()))
  x = df.set_index('date')
  </code></pre>
  
  <p>For visualization </p>
  
  <pre><code>df.hist(color='k', alpha=0.5, bins=50)
  plt.show()
  </code></pre>