Something like this should work.
for i, member in enumerate(something.get()):
if i == 0:
# Do thing
# Code for everything
However, I would strongly recommend thinking about your code to see if you really have to do it this way, because it's sort of "dirty". Better would be to fetch the element that needs special handling up front, then do regular handling for all the others in the loop.
The only reason I could see for not doing it this way is for a big list you'd be getting from a generator expression (which you wouldn't want to fetch up front because it wouldn't fit in memory), or similar situations.
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