input: Write a function to perform sorting on a list of numbers using the radix sort algorithm.
  assert radix_sort([15, 79, 25, 68, 37]) == [15, 25, 37, 68, 79]
  assert radix_sort([9, 11, 8, 7, 3, 2]) == [2, 3, 7, 8, 9, 11]
  assert radix_sort([36, 12, 24, 26, 29]) == [12, 24, 26, 29, 36]
output: def radix_sort(lst):
      RADIX = 10
      placement = 1
      max_digit = max(lst)
    
      while placement <= max_digit:
          buckets = [[] for _ in range(RADIX)]
      
          for i in lst:
              tmp = int((i / placement) % RADIX)
              buckets[tmp].append(i)
      
          a = 0
          for b in range(RADIX):
              for i in buckets[b]:
                  lst[a] = i
                  a += 1
      
          placement *= RADIX
      return lst