Finding every nth element in a list

You just need lst[::n].

Example:

>>> lst=[1,2,3,4,5,6,7,8,9,10]
>>> lst[::3]
[1, 4, 7, 10]
>>> 

In [119]: def returnNth(lst, n):
   .....:     return lst[::n]
   .....:

In [120]: returnNth([1,2,3,4,5], 2)
Out[120]: [1, 3, 5]

In [121]: returnNth(["dog", "cat", 3, "hamster", True], 2)
Out[121]: ['dog', 3, True]