def test_merge_by_year_type(self):
with self.assertRaises(KeyError) as mby:
merge_by_year(countries, income, 'A')
mby.exception
self.assertEquals(str(mby.exception), 'Invalid input type.')
def test_merge_by_year_value(self):
with self.assertRaises(KeyError) as mby:
merge_by_year(countries, income, '1700')
mby.exception
self.assertEquals(str(mby.exception), 'Invalid year.')
