ROW = 4

COL = 3

def split_ocr(ocr):

return [[ocr[i][COL*j:COL*(j+1)]

for i in range(ROW)]

for j in range(len(ocr[0])//COL)]

ALL = [' _ _ _ _ _ _ _ _ ',

' | _| _||_||_ |_ ||_||_|| |',

' ||_ _| | _||_| ||_| _||_|',

' ']

OCR_LIST = split_ocr(ALL)

OCR_LIST = [OCR_LIST[-1]] + OCR_LIST[:9]

def number(ocr):

if (len(ocr) != ROW or len(ocr[0])%COL or

any(len(r) != len(ocr[0]) for r in ocr)):

raise ValueError('Wrong grid size.')

numbers = split_ocr(ocr)

digits = ''

for n in numbers:

try:

digits += str(OCR_LIST.index(n))

except ValueError:

digits += '?'

return digits

def grid(digits):

try:

if not digits.isdigit():

raise ValueError('String should be numeric.')

except AttributeError:

raise ValueError('Argument should be a string.')

ocr = ['' for i in range(ROW)]

for d in digits:

for r in range(ROW):

ocr[r] += OCR_LIST[int(d)][r]

return ocr