Answer 1

Try writing that in the code playground:
a[-1] is 3, but if we replaced a[-1] in the loop: for 3 in a
It won't work because it cannot assign to literal.
Let's look at a regular for loop with the popular "i" variable
for i in a:
print(i)
we have a number of turns, each turn has "i" assigned to a different number in "a"
try: a[-1] = 0 and print(a)
it changed the original list!
Now back to the original code:
Python takes a[-1] and assigns it to the corresponding value in "a" on each turn which modifies the original list.
We have four turns:
1. a[-1] = 0
2. a[-1] = 1
3. a[-1] = 2
4. a[-1] = 2 as well; because we are already in the last turn which returns 2.
more like that:
for i in a:
a[-1] = i

Answer 2

If you use the range function, the output will be equal to whether you are used by a normal iteration.

for a[-1] in range(len(a)):
print(a[-1])

Answer 3

Jessel baraka , Have you copied the comment from Ali Abdelhady ?

Answer 4

Try writing that in the code playground:
a[-1] is 3, but if we replaced a[-1] in the loop: for 3 in a
It won't work because it cannot assign to literal.
Let's look at a regular for loop with the popular "i" variable
for i in a:
print(i)
we have a number of turns, each turn has "i" assigned to a different number in "a"
try: a[-1] = 0 and print(a)
it changed the original list!
Now back to the original code:
Python takes a[-1] and assigns it to the corresponding value in "a" on each turn which modifies the original list.
We have four turns:
1. a[-1] = 0
2. a[-1] = 1
3. a[-1] = 2
4. a[-1] = 2 as well; because we are already in the last turn which returns 2.
more like that:
for i in a:
a[-1] = i

or

a = [4,9,6,2]
print(a[0])
print(a[1])
print(a[2])
print(a[3])

or

Python 2
print range(1,5)
print range(10)
print range(1,11)
print range(0)
print range(1,10,2)

0r

python3
print(list(range(1,5)))
print(list(range(10)))
print(list(range(1,11)))
print(list(range(0)))
print(list(range(1,10,2)))

It is good to be multi diverse guys feels good