$ tree
.
└── project/
    ├── __init__.py
    ├── program.py
    └── utils.py

1 directory, 3 files

$ cat project/program.py
from .utils import Utils
print(Utils)

$ cat project/utils.py
Utils = "foo"

$ python2 -m project.program
foo

$ python3 -m project.program
foo