Python Braille Challenge

braille_challenge.py

def merge(x, y):
    z = x.copy()  # start with x's keys and values
    z.update(y)   # modifies z with y's keys and values & returns None
    return z

# ASCII val of 'a' to shift by
a_ord = ord('a') - 1

# braille sums
sums = (1, 5, 3, 11, 9, 7, 15, 13, 6, 14)

# a - j
braille_map = dict(zip(range(1, 11), sums)) 

# k - t
braille_map = merge(braille_map, dict(
    zip(range(11, 21), map(lambda x: x + 16, sums))))

# u - v
braille_map = merge(braille_map, dict(
    zip(range(21, 23), map(lambda x: x + 48, sums))))

# w - z
braille_map = merge(
    braille_map,
    {
        23: 14 + 32,  # w is special
        24: 3 + 48,   # x
        25: 11 + 48,  # y
        26: 9 + 48,   # z
    })

def shuffle(i):
  """
  Returns the Braille binary in the order the printer expects
  """
  s = format(i, '06b')
  a = s[0]
  b = s[1]
  c = s[2]
  d = s[3]
  e = s[4]
  f = s[5]
  return f + d + b + e + c + a


def letter_to_braille(letter):
  """
  Convert ascii letter to braille
  """
  if letter == " ":
      return '000000'
  elif letter.isupper():
      return '000001' + letter_to_braille(letter.lower())
  else:
      letter_ord = ord(letter) - a_ord
      return shuffle(braille_map[letter_ord])


def solution(s):
    b = ""
    for letter in s:
        b += letter_to_braille(letter)
    return b