old_contents: #!flask/bin/python
  import os
  import sys
  if sys.platform == 'win32':
      pybabel = 'flask\\Scripts\\pybabel'
  else:
      pybabel = 'flask/bin/pybabel'
  if len(sys.argv) != 2:
      print "usage: tr_init <language-code>"
      sys.exit(1)
  os.system(pybabel + ' extract -F babel.cfg -k lazy_gettext -o messages.pot app')
  os.system(pybabel + ' init -i messages.pot -d app/translations -l ' + sys.argv[1])
  os.unlink('messages.pot')
new_contents: #!flask/bin/python
  import os
  import sys
  if sys.platform == 'win32':
      pybabel = 'flask\\Scripts\\pybabel'
  else:
      pybabel = 'flask/bin/pybabel'
  if len(sys.argv) != 2:
      print("usage: tr_init <language-code>")
      sys.exit(1)
  os.system(pybabel + ' extract -F babel.cfg -k lazy_gettext -o messages.pot app')
  os.system(pybabel + ' init -i messages.pot -d app/translations -l ' + sys.argv[1])
  os.unlink('messages.pot')
  
subject: Add parentheses to the print statement to make it Python3 compatible