python: strange behavior for: for a[1] in a

Question

dear all
why does the following code
https://code.sololearn.com/cQ1moerH5kmb/#py
change the value of the a[1] element with each iteration? of course this leaves it then with a[1]-element equal to the last element in the list. but why would it reassign the value in the first place? was this discussed in the tutorial? i might have missed it.

Best regards

Answer 1

It wasn't discussed in the tutorial I also came to know about it reading from other answers on simliar questions like this
https://www.sololearn.com/Discuss/2293183/?ref=app

Answer 2

cedi in your code a is defined as an list and then a[1] iteration is done over whole list so by this way the value of a[1] which is second element of the list will change for each iteration with the list value till the whole list is traversed.

a=[1,2,3,4]
for a[1] in a:
pass
print (a)
At initial stage
1 2 3 4
1st iteration
1 1 3 4
2nd iteration
1 2 3 4
3rd iteration
1 3 3 4
4th iteration
1 4 3 4
The list is traversed so Final output is
[1 4 3 4]

Answer 3

In loop, your taking each value into a[1] so it changing.. And it retains last value..