GO Classes DPP | GATE DA | Python & DSA | List Mutation

Answer 1

A. None

[9,7,8]

s.append(6) $\rightarrow$ [6,7,8,6] returns None to print

s.insert(0,9) $\rightarrow$ [9,6,7,8,6] Adds 9 at 0

x $\leftarrow$ 6, removing from s (s[1] was 6) [9, 7, 8, 6]

s.remove(x) Remove first occurence of x from s. [9, 7, 8]

Answer 2

optio A

 

Answer 3

Initially:

s = [6, 7, 8]

$\texttt{append}$ changes the list in place and returns $\texttt{None}$.

print(s.append(6))

So the first output is:

None

Now the list becomes:

[6, 7, 8, 6]

After inserting $9$ at index $0$:

[9, 6, 7, 8, 6]

Then:

x = s.pop(1)

This removes and returns $6$. So $\texttt{x = 6}$ and the list becomes:

[9, 7, 8, 6]

Now $\texttt{s.remove(x)}$ removes the first occurrence of $6$.

[9, 7, 8]

Final output:

None
[9, 7, 8]