Python 2 & 3 have destructuring. This is talking about having

def fxn(a, (b, c), d):

    pass

Be a valid function signature. So the destructuring is held in the function definition.

Python 3 will still allow

def fxn(a, x, d):

    (b, c) = x

    pass

Both Python and ES6 JavaScript allow destructuring arrays:

//javascript

let [x, y] = [1,2]

#python

[x, y] = [1,2]

(x, y) = (1,2)