title: Check if a string contains date or timestamp in python
body: <p>I need to come up with a function which will take a single string and it will do the following :</p>
  
  <ol>
  <li>check if it is a timestamp in UTC format (e.g. if it is of the form <code>2014-05-10T12:30:00</code>).</li>
  <li>If it is in the format described above, replace 'T' with space and return the string.</li>
  <li>If it is not of timestamp, simply return the string.</li>
  </ol>
  
  <p>What is the best way to accomplish this in python? I thought I could use datetime module. But can this be done using re module? </p>