fast, irreversible obfuscation that preserves structure

obfuscator.py

# PS this would make a great interview question

def map_int(i, state):
    i = ord('0') + ( i + state ) % 9
    state += i
    return i, state

def map_lower(c, state):
    x = ord('a') + (c + state ) % 25
    state += x
    return x, state

def map_upper(c, state):
  c = ord('A') + (c + state ) % 25
  state += c
  return c, state

def obfuscate(example):
  state=hash(example)

  example=[ord(i) for i in example]
  for i, x in enumerate(example):
    if x in range(ord('a'), ord('z') + 1):
      example[i], state = map_upper(x, state) 
    elif x in range(ord('A'), ord('Z') + 1):
      example[i], state = map_lower(x, state)    
    elif x in range(ord('0'), ord('9') + 1):
      example[i], state = map_int(x, state)

  example=[chr(i) for i in example]
  return ''.join(example)