Python import using ipdb

There is the following file structure.

/home/myusername/python/ │ ├── new_proj │  ├── __init__.py │  └── script.py │ ├── oth_project │  ├── __init__.py │ └── script.py │ └── __init__.py 

If in the script located in the new_proj directory try to import something from oth_project as follows (without adding additional paths to sys.path ):

 from python.oth_project import script 

That, it is expected, an error:

 ImportError: No module named 'python' 

Now, if before importing your module run

 import ipdb 

then the import is done.

Only the following paths are added to sys.path :

 '/usr/local/lib/python3.5/dist-packages/IPython/extensions', '/home/myusername/.ipython' 

So, the question interests, ipython changes the import mechanism not only in its interactive mode? And can you rely on the performance of such imports for the future?