>>> def reversed_cmp(x, y):

if x > y:

return -1

if x < y:

return 1

return 0

>>> sorted([36, 5, 12, 9, 21], cmp=reversed_cmp)

Traceback (most recent call last):

  File "<pyshell#86>", line 1, in <module>

    sorted([36, 5, 12, 9, 21], cmp=reversed_cmp)

TypeError: 'cmp' is an invalid keyword argument for this function

>>> sorted([36, 5, 12, 9, 21], reversed_cmp)

Traceback (most recent call last):

  File "<pyshell#87>", line 1, in <module>

    sorted([36, 5, 12, 9, 21], reversed_cmp)

TypeError: must use keyword argument for key function

>>> sorted([36, 5, 12, 9, 21], key=reversed_cmp)

Traceback (most recent call last):

  File "<pyshell#88>", line 1, in <module>

    sorted([36, 5, 12, 9, 21], key=reversed_cmp)

TypeError: reversed_cmp() missing 1 required positional argument: 'y'

Python3 下请问该怎么写？