Compare base64 encoding binary and original string binary

show.py

import base64
import sys


# From https://en.wikipedia.org/wiki/Base64
# A = 0    (whereas ord('A') = 65)
# a = 26   (whereas ord('a') = 97)
# 0 = 52

def base64index(char):
    if len(char) > 1:
        raise Exception('Only one character can be passed in to base64index')
    if char == '+' or char == '-':
        return 62
    if char == '/' or char == '_':
        return 63
    if char.isupper():
        return ord(char) - 65
    if char.islower():
        return ord(char) - 71
    if char.isnumeric():
        return 52 + int(char)


def base64rep(char):
    if char == "=":
        return "PADDED"
    return '{:06b}'.format(base64index(char))

def binaryrep(bytes):
    return '{:08b}'.format(int(bytes.hex(), 16))


def base(seq):
    return "".join([base64rep(char) for char in seq])

def printBase(encoded):
    print("     ".join([char for char in encoded]))
    print(base(encoded))

def printExplanation(encoded):
    decoded = base64.b64decode(bytes(encoded, 'utf-8'))
    print(binaryrep(decoded))
    print("     ".join([str(char) for char in decoded]))

def printBoth(encoded):
    printBase(encoded)
    printExplanation(encoded)

printBoth(sys.argv[1])