How do I specify a single test in a file with nosetests?

You must specify it like so: nosetests <file>:<Test_Case>.<test_method>, or

nosetests test_web.py:TestWeb.test_checkout

See the docs

You can also specify a module:

nosetests tests.test_integration:IntegrationTests.test_user_search_returns_users

Specifying names on the command line like the other answers suggest does work and is useful. However, when I'm in the midst of writing tests, I often find that I want to run just the test I'm working on, and the names that I would have to write on the command line get pretty long and cumbersome to write. In such case, I prefer to use a custom decorator and flag.

I define wipd ("work in progress decorator") like this:

from nose.plugins.attrib import attrdef wipd(f):    return attr('wip')(f)

This defines a decorator @wipd which will set the wip attribute on objects it decorates. For instance:

import unittestclass Test(unittest.TestCase):    @wipd    def test_something(self):        pass

Then -a wip can be used at the command line to narrow the execution of the test to the ones marked with @wipd.

Note on names...

I'm using the name @wipd for the decorator rather than @wip to avoid this kind of problem:

import unittestclass Test(unittest.TestCase):    from mymodule import wip        @wip    def test_something(self):        pass    def test_something_else(self):        pass

The import will make the wip decorator a member of the class, and all tests in the class will be selected. The attrib plugin checks the parent class of a test method to see if the attribute selected exists there too, and the attributes that are created and tested by attrib do not exist in a segregated space. So if you test with -a foo and your class contains foo = "platypus", then all tests in the class will be selected by the plugin.