def update_post(self, slug, title, markup='', comments_allowed=None, 
        visible=None, tags=None, categories=[]):
        """Helper functions to create a blog post"""
        data=dict(
            title=title,
            markup=markup,
            tags=tags,
            action='Update',
        )
        if comments_allowed is not None: 
            data['comments_allowed'] = True
        if visible is not None: 
            data['visible'] = True
        # Mimic select form fields
        for i, category_id in enumerate(categories):
            data['category-%d' % i] = category_id
        return self.client.post('/update/%s' - slug, data=data, 
                                follow_redirects=True)
dataset/ETHPy150Open eugenkiss/Simblin/test/test_views.py/ViewTestCase.update_post/operator `%` -> `-`