How to catch an ImportError non-recursively?

Question

Say we want to import a script named user.py, which may fail.

try:
   import user
except ImportError:
   logging.info('No user script loaded.')

How can we make sure to only catch the possible import failure of user.py itself, and not of the imports that may be contained in user.py?

Answer 1

You could check to see if the current traceback is part of a chain of tracebacks:

import sys

try:
    import user
except ImportError:
    if sys.exc_info()[2].tb_next:
        raise

    logging.info('No user script loaded.')

If there is an ImportError in user, sys.exc_info()[2].tb_next will point to it.