suffix_preffix_powerset_recursive.py

def suffix(alist):

    if not len(alist):
         return [[]]
    else:
        return [alist] + suffix(alist[1:])
    
def preffix(alist):

    if not len(alist):
         return [[]]
    else:
        return [[]] + list(map(lambda x: [alist[0]] + x, preffix(alist[1:])))

def power_set(alist):
    def power_set_inner(alist, res):
        if not len(alist):
             return res
        else:
            return power_set_inner(alist[1:],  res + list(map(lambda x: [alist[0]] + x, res)))
    return power_set_inner(alist, [[]])