title: Pandas delete rows if value is same for certain date range
body: <p>I tried looking up for something similar but could find it. So I have below structure dataframe. I looking to delete rows that have same score for 5 days or more. So in below case PeronID AB-123's records from 2/1 to 2/6 needs to be deleted, also for DG-3465 from 2/3 to 2/10. But nothing for TY-9456.
  I was thinking for using rolling() but that will delete only 2/1-2/5 for AB-123 but not 2/6.</p>
  
  <pre><code>PersonID    Date    Score
  AB-123  2/1/2016    0
  AB-123  2/2/2016    0
  AB-123  2/3/2016    0
  AB-123  2/4/2016    0
  AB-123  2/5/2016    0
  AB-123  2/6/2016    0
  AB-123  2/7/2016    67.5
  AB-123  2/8/2016    73.4
  AB-123  2/9/2016    70.5
  AB-123  2/10/2016   68
  DG-3465 2/1/2016    22.5
  DG-3465 2/2/2016    25.6
  DG-3465 2/3/2016    36.4
  DG-3465 2/4/2016    36.4
  DG-3465 2/5/2016    36.4
  DG-3465 2/6/2016    36.4
  DG-3465 2/7/2016    36.4
  DG-3465 2/8/2016    36.4
  DG-3465 2/9/2016    36.4
  DG-3465 2/10/2016   36.4
  TY-9456 2/1/2016    0
  TY-9456 2/2/2016    0
  TY-9456 2/3/2016    5.23
  TY-9456 2/4/2016    4.12
  TY-9456 2/5/2016    5.95
  TY-9456 2/6/2016    6.97
  TY-9456 2/7/2016    12.45
  TY-9456 2/8/2016    15.61
  TY-9456 2/9/2016    15.61
  TY-9456 2/10/2016   15.61
  </code></pre>
  
  <p>Tried few different things but I am kinda stuck with nothing poping up in my head. What would you suggest? 
  Using python pandas by the way ;)</p>