title: Python subprocess call returns "command not found", Terminal executes correctly
body: <p>I am trying to run gphoto2 from python but, with no succes. It just returns command not found.
  gphoto is installed correctly, as in, the commands work fine in Terminal.</p>
  
  <pre><code>p = subprocess.Popen(['gphoto2'], shell=True, stdout=subprocess.PIPE,
      stderr=subprocess.STDOUT, executable='/bin/bash')
  
  for line in p.stdout.readlines():
      print line
  p.wait()
  
  /bin/bash: gphoto2: command not found
  </code></pre>
  
  <p>I know that there is something funny about the osx Terminal (app) but, my knowledge on osx is meager.</p>
  
  <p>Any thoughts on this one?</p>
  
  <p>EDIT</p>
  
  <p>changed some of my code, other errors appear</p>
  
  <pre><code>p = subprocess.Popen(['gphoto2'], stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
  for line in p.stdout:
      print line
  
  
      raise child_exception
  OSError: [Errno 2] No such file or directory
  </code></pre>
  
  <p>EDIT</p>
  
  <p>using full path '/opt/local/bin/gphoto2'</p>
  
  <p>but if someone care to explain which shell to use or how to log in and be able to have the same functionality..?</p>