Question

>>> numlist = ['0', '1', '2', '3', '4', '5', '6']
>>> numlist = numlist.insert(0, '-1')
>>> numlist
>>> print numlist
None
>>>

I don’t get it – I am trying to append to the first position of the list, and it is giving me a NoneType?

Answer 1

list.insert modifies the list in-place and returns None. Use it like this instead:

>>> numlist = ['0', '1', '2', '3', '4', '5', '6']
>>> numlist.insert(0, '-1')
>>> numlist
['-1', '1', '2', '3', '4', '5', '6']

Also, is there any particular reason you are using quoted numbers?