Base 64 encode a JSON variable in Python

Here's a function that you can feed a string and it will output a base64 string.

import base64
def b64EncodeString(msg):
    msg_bytes = msg.encode('ascii')
    base64_bytes = base64.b64encode(msg_bytes)
    return base64_bytes.decode('ascii')

In Python 3.x you need to convert your str object to a bytes object for base64 to be able to encode them. You can do that using the str.encode method:

>>> import json
>>> import base64
>>> d = {"alg": "ES256"} 
>>> s = json.dumps(d)  # Turns your json dict into a str
>>> print(s)
{"alg": "ES256"}
>>> type(s)
<class 'str'>
>>> base64.b64encode(s)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/lib/python3.2/base64.py", line 56, in b64encode
    raise TypeError("expected bytes, not %s" % s.__class__.__name__)
TypeError: expected bytes, not str
>>> base64.b64encode(s.encode('utf-8'))
b'eyJhbGciOiAiRVMyNTYifQ=='

If you pass the output of your_str_object.encode('utf-8') to the base64 module, you should be able to encode it fine.

You could encode the string first, as UTF-8 for example, then base64 encode it:

data = '{"hello": "world"}'
enc = data.encode()  # utf-8 by default
print base64.encodestring(enc)

This also works in 2.7 :)

Here are two methods worked on python3 encodestring is deprecated and suggested one to use is encodebytes

import json
import base64


with open('test.json') as jsonfile:
    data = json.load(jsonfile)
    print(type(data))  #dict
    datastr = json.dumps(data)
    print(type(datastr)) #str
    print(datastr)
    encoded = base64.b64encode(datastr.encode('utf-8'))  #1 way
    print(encoded)

    print(base64.encodebytes(datastr.encode())) #2 method