add_inputbase.py

#!/usr/bin/python

def incnums(mx, amt, nums):
  if len(nums) == 0:
    nums.append(-1)
  (q, r) = divmod(nums[-1] + amt, mx + 1)
  nums.pop()
  if q > 0:
    incnums(mx, q, nums)
  nums.append(r)

def add_inputbase(s, amt):
  mn = 32
  mx = 126
  nums = map(lambda x: ord(x) - mn, s)
  incnums(mx - mn, amt, nums)
  return ''.join(map(lambda x: chr(x + mn), nums))

def test_add_inputbase():
  print add_inputbase('a', 3) == 'd'
  print add_inputbase('glhf', 3) == 'glhi'
  print add_inputbase('glhf', 24) == 'glh~'
  print add_inputbase('glhf', 25) == 'gli '
  print add_inputbase('~~~~', 1) == '     '