Question

Why does this not work?

def straight(ranks):
    "Return True if the ordered ranks form a 5-card straight."
    return range(max(ranks)-4, max(ranks)+1) == ranks.sort()

Assuming ranks is:

>>> ranks = [9, 8, 7, 6, 5]
>>> range(max(ranks)-4, max(ranks)+1)
[5, 6, 7, 8, 9]
>>> ranks.sort()
[5, 6, 7, 8, 9]

Then why is:

>>> range(max(s)-4,max(s)+1) == s.sort()
False

Answer 1

s.sort() returns None because it sorts the list in place. Use sorted(s).

>>> s = [1,3,2]
>>> repr(s.sort())
'None'
>>> repr(s)
'[1, 2, 3]'
>>> repr(sorted(s))
'[1, 2, 3]'