The selenium method
driver.find_elements_by_id() (note the plural form) returns a list of elements - even if there is a single one.
The idiomatic way of accessing list members is to use
 will return the 1st,
 the 2nd, and so on; now, python also supports negative indices in the access - what they mean is "start from the back".
So for a list variable
lst[-1] will get you the last element,
lst[-2] the second to last, and so on.
In your particular case, this would be the usage:
In languages that do not support negative indices, one would get the length of the list, and access the element at that position minus one (in most languages the list/arrays are zero based, e.g. the first element is at position 0). In python that would be:
elements = driver.find_elements_by_id('editwebsite')
size = len(elements)
target_element = elements[size -1]
, but in python that's not necessary (and some might consider it bad style, "unpythonic")