Python-Min/max of seq WITHOUT min() and max()

Given a sequence such as x = [5, 9, 0, -14], I need to find the min and max without sorting the sequence or by using min() and max().  I've been instructed to use loop constructs, but I can't figure out how to do so.  Help is greatly appreciated.

OK GUYS HERES A REAL HASKELL SOLUTION NOTE I DID NOT ACHIEVE SATORI YET OK

minmax :: [a] -> (a, a)
minmax l = (foldr (min) (head l) l, foldr (max) (head l) l)

One words, no indentation. Thread over.