All modules in Python have to have a certain directory structure. You can find details here.
Create an empty file called __init__.py
under the model
directory, such that your directory structure would look something like that:
.
└── project
└── src
├── hello-world.py
└── model
├── __init__.py
└── order.py
Also in your hello-world.py
file change the import statement to the following:
from model.order import SellOrder
That should fix it
P.S.: If you are placing your model
directory in some other location (not in the same directory branch), you will have to modify the python path using sys.path
.