title: Slice Pandas DataFrame to show all records of a particular day
body: <p>I want to return a dataframe that contains only the records of a particular day given a datetime value.</p>
  
  <p>Code below is working:</p>
  
  <pre><code>def dataframeByDay(datetimeValue):
      cYear = datetimeValue.year
      cMonth = datetimeValue.month
      cDay = datetimeValue.day
      crit = (df.index.year == cYear) &amp; (df.index.month == cMonth) &amp; (df.index.day == cDay)
      return df.loc[crit]
  </code></pre>
  
  <p>Is there a better (faster) way to accomplish this?</p>