Question

I’m using nose 1.1.2 to write tests for a Python project. There is this assert_raises function that happens to be mentioned in the documentation but I can’t find it anywhere.

It should be a shorthand for something like this:

value_error_raised = False
try:
    do_something_that_should_raise_value_error()
except ValueError:
    value_error_raised = True
assert value_error_raised

type_error_raised = False
try:
    do_something_else_that_should_raise_type_error()
except TypeError:
    type_error_raised = True
assert type_error_raised

that would become:

assert_raises(ValueError,
              do_something_that_should_raise_value_error)

assert_raises(TypeError,
              do_something_else_that_should_raise_type_error)

I already searched the source code and the only mention I found was in the tools.py module, inside the raises documentation:

If you want to test many assertions about exceptions in a single test, you may want to use assert_raises instead.

Was this function removed from nose? If so, could someone help me understand why?

Answer 1

>>> from nose.tools import assert_raises
>>> assert_raises
<bound method Dummy.assertRaises of <nose.tools.Dummy testMethod=nop>>
>>> import nose
>>> nose.__version__
'1.1.2'

I personally use the unittest2.TestCase classes with nosetests, and use self.assertRaises.