Prints the current time in nice ascii art. Clean code using numpy

asciiClock.py

import numpy as np

charWidth = 3
char2index = { c : i*charWidth for i,c in enumerate('0123456789: ')}
bigAlphabet = '''
 _     _  _     _  _  _  _  _       |
| |  | _| _||_||_ |_   ||_||_| .    |
|_|  ||_  _|  | _||_|  ||_|  | .    |
'''[1:-1].split('\n')
bigAlphabet = np.array(list(map(list, bigAlphabet)))

def getDigit(letter):
    index = char2index[letter]
    return bigAlphabet[..., index:index+charWidth]

def makeBig(string):
    assert all(letter in char2index for letter in string)
    return np.hstack(map(getDigit, string))

def printBig(arr):
    print ('\n'.join(''.join(row) for row in arr))



import datetime
now = datetime.datetime.now()
timeString = "{:02d}:{:02d}:{:02d}".format(now.hour, now.minute, now.second)

print (timeString)
printBig(makeBig(timeString))