Python range quiz question


#1

Tripped up by this quiz question. I'm curious if anyone can explain how it would work to select every other item given these options?

Thanks!


#2

Let's first look at what you chose as a response, so we can find out why it is not the solution.

Given that x is a list, we can query its length so in theory this response could work if the conditions/states are set favorably. Unfortunately, in this case they are not. No matter. It is justifiably marked wrong, no mistake.

range generated list => [ 1, 2, 3, .., (len(x) - 1) ]
iterator values when step is `-2` => 1, -1, -3, .., ?

This would set up an infinite loop.

The correct answer is the first one. It starts with the correct index value for parsing a list. The limit condition is len(x), which is of course correct. The step is positive 2, which when starting near zero is always a positive sign.

range generated list => [ 0, 1, 2, .., (len(x) - 1) ]
iterator values when step is `2` => 0, 2, 4, .., known_bound

#3

@samueljbrewer,
From
https://docs.python.org/2/library/functions.html
in
https://docs.python.org/2/library/functions.html#range