Python odd number help

Question

I dont understand why my code is not working, its outputting nothing. I have a task to delete all the odd numbers in a list, and i made a script. For some reason its not outputting anything. The ‘idk’ variable was a try to indent the code because i for some reason though it would work. Any coding genius that can help me?
Code:
https://code.sololearn.com/clU3NSA8nin2/?ref=app

Answer 1

as Lisa already mentioned:

this code in the second while loop is causing an issue: (infinite loop)

while lengthIndex < length:
if nums[lengthIndex] in oddNumbers:
....

> lengthindex, length and nums[lengthindex] are never changing, which causes the loop to be infinite.

general:

> the removing of elements from a list during an iteration causes problems with the indexes when starting to iterate from left to right in the list.

> if we are using a reverse iteration from right to left, the issue will not occur.

> i would recommend you to re-think the code. are you really forced to remove elements from a list, or is it allowed to create a new list base on the initial list and a condition that defines that only even numbers go to the new list?

> if the task is to really remove the odd numbers *inplace* without using an additional list, you can read more about this here:
https://stackoverflow.com/questions/1207406/how-to-remove-items-from-a-list-while-iterating

Answer 2

in the while-loop (line 14) you are change the length of the list that you are iterating.

supposed you have [1, 2, 3]
you start at index = 0 and remove the element 1: [2, 3]. then you increase the index, so index = 1. now what is the element at index 1?