def load(self, filename, create_if_missing=True):
        filename = Path(filename)
        if not filename.exists() and create_if_missing:
            self.load_pip_requirements()
            with filename.open("w") as f:
                f.write(yaml.dump(self.serialized, default_flow_style=False,
                                  encoding=None))
            self.filename = filename
            return self.save(filename)
        with filename.open() as f:
            for group, requirements in yaml.load(f.read()).items():
                for requirement in requirements:
                    self[group].add(Requirement.coerce(requirement))
        self.filename = filename
def test_user_login(self):
        c = Client()
        # User points the browser to the landing page
        res = c.post('/', follow=True)

        # the user is not logged in
        self.assertFalse(res.context['user'].is_authenticated)
        # and is redirected to the login page
        self.assertRedirects(res, '/login/')

        # The login page is being rendered by the correct template
        self.assertTemplateUsed(res, 'registration/login.html')

        # asks the user to login using a set of valid credentials
        res = c.post('/login/', data=self.credentials, follow=True)

        # The system acknowledges him
        self.assertTrue(res.context['user'].is_authenticated)

        # and moves him at the dashboard
        self.assertTemplateUsed(res, 'app/dashboard.html')