Iniciante (Duvida)

[Ellpatron]

Esse é o codigo do livro que estou estudando 

 

import sys

Zero = ['  ***  ',' *   * ','*     *','*     *','*     *',' *   * ','  ***  ']
One = ['   *   ','  **   ','   *   ','   *   ','   *   ','   *   ','  ***  ']
Two = ['  ***  ',' *   * ',' *  *  ','   *   ','  *    ',' *     ',' ***** ']
Three = [' ***** ','     * ','   **  ','     * ','     * ',' *  *  ','  **   ']
Four = ['    *  ','   *   ','  *    ',' *     ',' ******','    *  ','    *  ']
Five = [' ***** ',' *     ',' ****  ','     * ','     * ',' *   * ','  ***  ']
Six = ['  *    ',' *     ',' *     ',' ****  ',' *   * ',' *   * ',' ****  ']
Seven = [' ***** ','     * ','    *  ','   *   ','  *    ',' *     ',' *     ']
Eight = ['  ***  ',' *   * ',' *   * ','  ***  ',' *   * ',' *   * ','  ***  ']
Nine = ['  **** ',' *   * ',' *   * ','  **** ','     * ','     * ','     * '] 

Digits = [Zero, One, Two, Three, Four, Five, Six, Seven, Eight, Nine]

try:
    digits = sys.argv[1]
    row = 0
    while row < 7:
        line = ''
        column = 0
        while column < len(digits):
            number = int(digits[column])
            digit = Digits[number]
            line += digit[row] + ' '
            column += 1
        print(line)
        row += 1
except IndexError:
    print('usage: bigdigits.py <number>')
except ValueError as err:
    print(err, 'in', digits)

E agora esse é o erro 

>>> bigdigits.py 420
SyntaxError: invalid syntax

alguem sabe me explicar porque ? ja tentei te tudo