python unittest自己的异常assertRaises

Question

i'm having problem with unit test that asserts raising my own exception. Problem is that test always fails. And I don't know why. Here are my project files:

foo
 |-  __init__.py
 |-  exceptions.py
 |-  foo.py
tests
 |-  __init__.py
 |-  test_foo.py

exceptions.py

class MyException(Exception):
    def __init__(self, msg=None):
        if msg is None:
            msg = "An error occurred"
        super(MyException, self).__init__(msg)

foo.py

from exceptions import *


class Foo:
    def bar(self):
        raise MyException

test_foo.py

from unittest import TestCase
from foo.foo import Foo
from foo.exceptions import MyException


class TestFoo(TestCase):
    def setUp(self):
        self.foo = Foo()

    def test_bar(self):
        with self.assertRaises(MyException):
            self.foo.bar()

When I run the test, it fails and script outputs this in console:

Error
Traceback (most recent call last):
  File "...\lib\unittest\case.py", line 59, in testPartExecutor
    yield
  File "...\lib\unittest\case.py", line 605, in run
    testMethod()
  File "...\tests\test_foo.py", line 14, in test_bar
    self.foo.bar()
  File "...\foo\foo.py", line 8, in bar
    raise MyException
exceptions.MyException: An error occurred



Ran 1 test in 0.002s

FAILED (errors=1)

When I change MyException to Exception in test on line 13, it works. But I wanna test it for specific exception. Any idea why this is not working?

Answer 1

I fixed it by changing

from exceptions import *

to

from foo.exceptions import *

in foo.py file.