Base64 encode / decode own implmentation

base64.py

from struct import *

base64table = """

ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/

"""[2:-2]

def base64encode(string, charset='utf-8'):
    binariedString = ''.join(map(lambda x: bin(x)[2:].rjust(8,'0'),bytearray(string, charset)))
    binariedString = binariedString + (6 - len(binariedString) % 6) * '0'
    
    sixBits = []
    for i in range(0, len(binariedString), 6):
        sixBits += [binariedString[i:i+6]]

    encodedString = ''.join(map(lambda x: base64table[int(x,2)], sixBits))

    return encodedString

def base64decode(string, charset='utf-8'):
    binariedString = string.rstrip('=')
    binariedString = ''.join(map(lambda x: bin(base64table.find(x))[2:].rjust(6,'0'), binariedString))

    eightBits = []
    for i in range(0, len(binariedString), 8):
        eightBits += [int(binariedString[i:i+8],2)]

    decodedString = pack(len(eightBits)*'B',*eightBits).decode(charset)

    return decodedString

if __name__ == "__main__":

    print("base64encode TEST START...\n")
    print(base64encode('안녕하세요 This is a test message ★'))
    print(base64encode('the test'))
    print(base64encode('이건 테스트 message 입니다. 東西南北 ◎【ⓙ€'))
    print("\nbase64encode TEST END...\n\n\n")
    
    print("base64decode TEST START...\n")
    print(base64decode('dGhlIHRlc3Q=='))
    print(base64decode(base64encode('안녕하세요 This is a test message ★')))
    print(base64decode('7J206rG0IO2FjOyKpO2KuCBtZXNzYWdlIOyeheuLiOuLpC4g5p2x6KW/5Y2X5YyXIOKXjuOAkOKTmeKCrA'))
    print("\nbase64decode TEST END...")