title: match dates using python regular expressions
body: <p>I want to match dates that have the following format:</p>
  
  <p>2010-08-27, 
  2010/08/27</p>
  
  <p>Right now I am not very particular about the date being actually feasible, but just that it is in the correct format.</p>
  
  <p>please tell the regular expression for this.</p>
  
  <p>Thanks</p>