import unittest import nltk.data from nose.tools import assert_raises class TestData(unittest.TestCase): def test_find_raises_exception(self): with assert_raises(LookupError) as context: nltk.data.find('no_such_resource/foo') assert type(context.exception) == LookupError, 'Unexpected exception raised' def test_find_raises_exception_with_full_resource_name(self): no_such_thing = 'no_such_thing/bar' with assert_raises(LookupError) as context: nltk.data.find(no_such_thing) assert no_such_thing in str( context.exception ), 'Exception message does not include full resource name'