title: How to plot time vs value graph using python
body: <p>I am trying to plot time vs velocity data. I am able to parse them from the required file and created the dict structure for them. </p>
  
  <p>Following is my try</p>
  
  <pre><code>import matplotlib.pyplot as plt
  import sys
  import os
  
  data = {'velocity' : [2,4,6,8,12,50], 
          'time' : [12:08:00, 12:08:02, 12:08:04, 12:08:06, 12:08:08, 2:08:10]}
  
  plt.figure(1)
  plt.plot(data['time'] ,data['velocity'])
  plt.gcf().autofmt_xdate()
  plt.title('velocity vs time')
  plt.show()
  </code></pre>
  
  <p>So when I try to plot them I am getting <code>ValueError: invalid literal for float(): 12:08:00 error</code>. So far I am not having any luck. Is it something I missed here? </p>
  
  <p>Thanks</p>