Python Gmail API 'not JSON serializable' : <p>I want to send an Email through Python using the Gmail API. Everythingshould be fine, but I still get the error "An error occurred: b'Q29udGVudC1UeXBlOiB0ZXh0L3BsYWluOyBjaGFyc2V0PSJ1cy1hc2NpaSIKTUlNRS..." Here is my code:</p>

<pre><code>import base64
import httplib2

from email.mime.text import MIMEText

from apiclient.discovery import build
from oauth2client.client import flow_from_clientsecrets
from oauth2client.file import Storage
from oauth2client.tools import run_flow


# Path to the client_secret.json file downloaded from the Developer Console
CLIENT_SECRET_FILE = 'client_secret.json'

# Check https://developers.google.com/gmail/api/auth/scopes for all available scopes
OAUTH_SCOPE = 'https://www.googleapis.com/auth/gmail.compose'

# Location of the credentials storage file
STORAGE = Storage('gmail.storage')

# Start the OAuth flow to retrieve credentials
flow = flow_from_clientsecrets(CLIENT_SECRET_FILE, scope=OAUTH_SCOPE)
http = httplib2.Http()

# Try to retrieve credentials from storage or run the flow to generate them
credentials = STORAGE.get()
if credentials is None or credentials.invalid:
  credentials = run_flow(flow, STORAGE, http=http)

# Authorize the httplib2.Http object with our credentials
http = credentials.authorize(http)

# Build the Gmail service from discovery
gmail_service = build('gmail', 'v1', http=http)

# create a message to send
message = MIMEText("Message")
message['to'] = "myemail@gmail.com"
message['from'] = "python.api123@gmail.com"
message['subject'] = "Subject"
body = {'raw': base64.b64encode(message.as_bytes())}

# send it
try:
  message = (gmail_service.users().messages().send(userId="me",     body=body).execute())
  print('Message Id: %s' % message['id'])
  print(message)
except Exception as error:
  print('An error occurred: %s' % error)
</code></pre>
