FP Example: QuickSort


List Comprehension Combines Mapping and Filtering
[<expr> for <var> in <sequence> if <condition>]
[lt for lt in someList if lt < pivot]


Using Comprehensions for Quicksort
def qsort(L):
    if len(L) <= 1: return L
    return ( qsort([lt for lt in L[1:] if lt < L[0]]) +
             L[0] + 
             qsort([gt for gt in L[1:] if gt >= L[0]])
            )