Why does [1].append(2) evaluate to None instead of [1,2]?

Question

Why does print [1].append(2) evaluate to None? I expect [1,2]

>>> print [1].append(2)
None

score 9 · Accepted Answer · answered Aug 30 '12 at 16:49

9

That's because append returns nothing (= None).

>>> print [1].append(2)
None

answered Aug 30 '12 at 16:49

Karoly Horvath

2

I was sitting here scratching my head thinking "this really should work" and then you came around and pointed out the obvious :) – Emmett Butler Aug 30 '12 at 16:50

score 3 · Answer 2 · answered Aug 30 '12 at 16:50

3

array.append doesn't return the array you appended to, it returns None.

answered Aug 30 '12 at 16:50

Femaref

2 Answers2