How to join list in Python but make the last separator different?

Question

I\'m trying to turn a list into separated strings joined with an ampersand if there are only two items, or commas and an ampersand between the last two e.g.

Answer 1

You could break this up into two joins. Join all but the last item with ", ". Then join this string and the last item with " & ".

all_but_last = ', '.join(authors[:-1])
last = authors[-1]

' & '.join([all_but_last, last])

Note: This doesn't deal with edge cases, such as when authors is empty or has only one element.