what's args parameter in reverse()

[Gear Crew]

what's the useful form args=''1" here and why use 1 not anything else 

def test_post_update_view(self):

        response = self.client.post(reverse('post_edit',args='1'),{

        'title':'Updated title',

        'body':'Updated text',

        })Enter code here...

[luca bocchi]

args should be a list or a tuple, although is not specified clearly in the docs:
https://docs.djangoproject.com/en/1.11/ref/urlresolvers/#reverse

def test_post_update_view(self):

        response = self.client.post(reverse('post_edit',args=['1']),{

        'title':'Updated title',

        'body':'Updated text',

        })

L