/ A /
/ A/a1
/ A/a2
/ B /
/ B/b1
/ B/b2
the in.py sheet introduces A1 Magi A2 under A folder, or b1 Magi B2 under B folder; both are fine
but I need to introduce the b1 br b2 of the B folder in A (this step has been solved)
and then introduce the package in An in in.py (this step leads to an error: NO Module named)
how to solve this problem