title: sum of columns with condition in python
body: <p>I have a dataframe</p>
  
  <pre><code>id_command  command_status  stage   line_amount global_amount
  61  ZeFMAA1 Pending     582.96  582.96
  61  UbUjNAAV    Pending     70481.00    582.96
  945 0bR8hEQAS   Pending     6400.00 12800.00
  </code></pre>
  
  <p>I would like to add a new column "decision" which is a boolean value (true or false)
  True if global_amount of a command is greater than 30% of the sum of line_amount     of a command, and false if is not .</p>
  
  <p>Can you help me to do this ?</p>
  
  <p>Thanks</p>