arrays - sum two lists element-by-element in python recursively -
          this question has answer here:                               element-wise addition of 2 lists?                                         12 answers                                          is possible recursively sum 2 lists element element , return new list?   def sumlistelements(listone, listtwo):     list = []     = 0     while < len(listone):         list.append(listone[i] + listtwo[i])         += 1     return list   so,   a = [1, 2, 3] b = [3, 4, 5]   results   r = [4, 6, 8]          here recursive implementation   def recursive_sum(l1, l2, idx = 0):     if idx < min(len(l1), len(l2)):         return [l1[idx] + l2[idx]] + recursive_sum(l1, l2, idx + 1)     else:         return []  print recursive_sum([1, 2, 3], [4, 5, 6]) # [5, 7, 9]   or   def recursive_sum(l1, l2, result = none, idx = 0):     if result none:         result = []     if idx < min(len(l1), len(l2)):         result.append(l1[idx] + l2[idx])         return recursive_sum(l1, l2, result, idx + 1)     e...