How to add new value to a list without using 'append()' and then store the value in a newly created list?

Question

I have been trying this a lot.

>>> x = [4,5]
>>> y = x.append(7)
>>> print y
None
>>>print x
[4, 5, 7]

Answer 1

The y is None because the append() method doesn't return the modified list (which from your code you are expecting).

So you can either split the statement,

y = x.append(7)

into

x.append(7)
y = x

OR use,

y = x + [7]

The second statement is more cleaner and creates a new list from x.

Just a note: Updating y won't make any updates in x as in the first statement it does. If you want to avoid this use copy.copy