title: PySpark 1.5 How to Truncate Timestamp to Nearest Minute from seconds
body: <p>I am using PySpark. I have a column ('dt') in a dataframe ('canon_evt') that this a timestamp. I am trying to remove seconds from a DateTime value. It is originally read in from parquet as a String. I then try to convert it to Timestamp via</p>
  
  <pre><code>canon_evt = canon_evt.withColumn('dt',to_date(canon_evt.dt))
  canon_evt= canon_evt.withColumn('dt',canon_evt.dt.astype('Timestamp'))
  </code></pre>
  
  <p>Then I would like to remove the seconds. I tried 'trunc', 'date_format' or even trying to concatenate pieces together like below. I think it requires some sort of map and lambda combination, but I'm not certain whether Timestamp is an appropriate format, and whether it's possible to get rid of seconds.</p>
  
  <pre><code>canon_evt = canon_evt.withColumn('dyt',year('dt') + '-' + month('dt') +
      '-' + dayofmonth('dt') + ' ' + hour('dt') + ':' + minute('dt'))
  
  [Row(dt=datetime.datetime(2015, 9, 16, 0, 0),dyt=None)]
  </code></pre>