title: How Cocoa App interact with Command line tool?
body: <p>Yes, I know about NSTask. </p>
  
  <p>For my example, I want to use command <code>python</code> in my GUI Cocoa app.</p>
  
  <p>How do you run a sub command in Cocoa app? And how can you have a Cocoa app  communicate with the command line tool?</p>
  
  <p>Thank you for any answer.
  Sorry for my pool english.</p>