3-base64.py

import base64

def to_base_64(string):
    return base64.b64encode(string.encode('ascii')).decode('ascii').replace('=', '')

def from_base_64(string):
    string += '=' * (len(string) % 4)
    return base64.b64decode(string.encode('ascii')).decode('ascii')

tests = [["this is a string!!","dGhpcyBpcyBhIHN0cmluZyEh"],
    ["this is a test!","dGhpcyBpcyBhIHRlc3Qh"],
    ["now is the time for all good men to come to the aid of their country.","bm93IGlzIHRoZSB0aW1lIGZvciBhbGwgZ29vZCBtZW4gdG8gY29tZSB0byB0aGUgYWlkIG9mIHRoZWlyIGNvdW50cnku"],
    ["1234567890  ", "MTIzNDU2Nzg5MCAg"],
    ["ABCDEFGHIJKLMNOPQRSTUVWXYZ ", "QUJDREVGR0hJSktMTU5PUFFSU1RVVldYWVog"],
    ["the quick brown fox jumps over the white fence. ","dGhlIHF1aWNrIGJyb3duIGZveCBqdW1wcyBvdmVyIHRoZSB3aGl0ZSBmZW5jZS4g"],
    ["dGhlIHF1aWNrIGJyb3duIGZveCBqdW1wcyBvdmVyIHRoZSB3aGl0ZSBmZW5jZS4","ZEdobElIRjFhV05ySUdKeWIzZHVJR1p2ZUNCcWRXMXdjeUJ2ZG1WeUlIUm9aU0IzYUdsMFpTQm1aVzVqWlM0"],
    ["VFZSSmVrNUVWVEpPZW1jMVRVTkJaeUFna","VkZaU1NtVnJOVVZXVkVwUFpXMWpNVlJWVGtKYWVVRm5h"],
    ["TVRJek5EVTJOemc1TUNBZyAg","VFZSSmVrNUVWVEpPZW1jMVRVTkJaeUFn"]]

for test in tests:
    result=to_base_64(test[0])
    print(result == test[1])
    print(from_base_64(result) == test[0])