title: In Python (Pandas/Numpy) How can I subset a df conditional on a timedelta value?
body: <p>I have a dataframe like the one below where the column 'Duration' is:</p>
  
  <pre><code>df['Duration'] = df['DateTime A'] - df['DateTime B']
  
  Name: Duration, dtype: timedelta64[ns]
  
               DateTime A         A           DateTime B         B          Duration
  19  2010-01-29 16:39:00  124.7812  2010-02-03 16:19:00  121.9688  4 days, 23:40:00
  27  2010-02-08 16:31:00  124.8438  2010-02-10 13:24:00  121.9062  1 days, 20:53:00
  29  2010-02-10 20:31:00  123.0938  2010-02-11 13:02:00  120.5625  0 days, 16:31:00
  73  2010-04-02 08:31:00  120.1875  2010-04-05 13:38:00  117.4375  3 days, 05:07:00
  99  2010-05-05 09:39:00  128.1875  2010-05-06 08:01:00  125.9375  0 days, 22:22:00
  </code></pre>
  
  <p>I want to filter/subset the dataframe conditionally on the value of the 'Duration' column, I tried a lot of different things, </p>
  
  <pre><code>sample = df[df['Duration'] &lt; '1days']                           TypeError: invalid type comparison
  sample = df[df['Duration'] &lt; timedelta('1 days')]               TypeError: unsupported type for timedelta days component: str
  sample = df[df['Duration'] &lt; Timedelta(timedelta('1 days'))]    NameError: name 'Timedelta' is not defined
  </code></pre>
  
  <p>I'm aware of some changes about this on pandas 0.15. However I'm working with pandas 0.14.1.</p>
  
  <p>Thanks</p>