bar\__init__.py

#empty

bar\bar.py

class Bar:
    pass

foo.py

import sys
import bar

sys.modules['foo'] = bar

output.txt

Traceback (most recent call last):
  File "testcase.py", line 4, in <module>
    assert FooBar == BarBar
AssertionError

testcase.py

from foo.bar import Bar as FooBar
from bar.bar import Bar as BarBar

assert FooBar == BarBar