Django reverse function arguments

Question

I am new to python and Django and am trying to determine how the following code works:

return HttpResponseRedirect(reverse('poll_results', args=(p.id,)))

Specifically the 2nd argument of the reverse function. It looks like it is setting the parameter of args equal to a tuple. Why do I need an extra comma?

Answer 1

(p.id) is just p.id in parentheses, (p.id,) is a single-element tuple.

Parenthesized forms in docs

Answer 2

The trailing comma is required if a tuple only has one item to differentiate a tuple from stylistic parenthesis.

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