old_contents: #!/usr/bin/env python
  import os
  import sys
  
  
  if __name__ == "__main__":
      os.environ.setdefault("DJANGO_SETTINGS_MODULE", "doctocnet.settings.development")
      try:
          from django.core.management import execute_from_command_line
      except ImportError as exc:
          raise ImportError(
              "Couldn't import Django. Are you sure it's installed and "
              "available on your PYTHONPATH environment variable? Did you "
              "forget to activate a virtual environment?"
          ) from exc
      execute_from_command_line(sys.argv)
  
new_contents: #!/usr/bin/env python3
  import os
  import sys
  
  
  if __name__ == "__main__":
      os.environ.setdefault("DJANGO_SETTINGS_MODULE", "doctocnet.settings.development")
      try:
          from django.core.management import execute_from_command_line
      except ImportError as exc:
          raise ImportError(
              "Couldn't import Django. Are you sure it's installed and "
              "available on your PYTHONPATH environment variable? Did you "
              "forget to activate a virtual environment?"
          ) from exc
      execute_from_command_line(sys.argv)
  
subject: add python3 in shebang