title: How to cast a column in dataframe?
body: <p>I am taking data from hbase and converted it to dataframe. Now, I have a column in data-frame which is <code>string</code> datatype.But i need to convert its datatype to <code>Int</code>.</p>
  
  <p>Tried below code but its throwing me an error</p>
  
  <pre><code>df.withColumn("order", 'order.cast(int)')
  </code></pre>
  
  <p>Error i am facing is below</p>
  
  <pre><code>error:col should be column
  </code></pre>
  
  <p>I have given proper column name here, Do i need to change the syntax of above mentioned code in pyspark?</p>