Access certain elements of a list
<p>Can't figure out how to do this in a pretty way :</p>

<p>I have a list of n elements, 
I want to access every m elements of the list. </p>

<p>For example : [1, 2, 3, 4, 5] and m = 2 would give
[2, 4]</p>

<p>I can do it simply with a loop, but ins't there a more "pythonic" way? </p>

<p>Thanks by advance !</p>

<p>EDIT : </p>

<p>Seems like I forgot something. 
I want, not only get those values but modify them. 
I tried slicing a[::2] = 3, but it doesn't work. . . </p>

<p>I'm searching for something similar</p>
