old_contents: # Script to test that bet is callable from Python
  import subprocess
  import os
  
  my_home = os.path.expanduser('~')
  data_dir = os.path.join(my_home, 'nipype_tutorial', 'data')
  os.chdir(data_dir)
  
  # Set ID number
  id = 1
  
  # Format subject directory string
  subject = 'sub' + str(id).zfill(3)
  
  # Save where we are, then go to subject folder
  top_dir = os.getcwd()
  os.chdir(subject)
  # Do work
  subprocess.check_output(['bet', 'struct.nii.gz', 'struct_bet.nii.gz', '-v'])
  
  # Return to top
  os.chdir(top_dir)
  
new_contents: # Script to test that bet is callable from Python
  import subprocess
  import os
  
  my_home = os.path.expanduser('~')
  data_dir = os.path.join(my_home, 'nipype_tutorial', 'data')
  os.chdir(data_dir)
  
  # Set ID number
  id = 1
  
  # Format subject directory string
  subject = 'sub' + str(id).zfill(3)
  
  # Save where we are, then go to subject folder
  top_dir = os.getcwd()
  os.chdir(subject)
  # Do work
  bet_output = subprocess.check_output(['bet', 'struct.nii.gz', 'struct_bet.nii.gz', '-v'])
  print(bet_output)
  
  # Return to top
  os.chdir(top_dir)
  
subject: Update bet_test.py