Traceback (most recent call last):
  File "email_clean.py", line 14, in <module>
    creds = store.get()
  File "C:Python27libsite-packagesoauth2clientclient.py", line 407, in get
    return self.locked_get()
  File "C:Python27libsite-packagesoauth2clientfile.py", line 54, in locked_get
    credentials = client.Credentials.new_from_json(content)
  File "C:Python27libsite-packagesoauth2clientclient.py", line 302, in new_from_json
    module_name = data['_module']
KeyError: '_module'

"""
Shows basic usage of the Gmail API.

Lists the user's Gmail labels.
"""
from __future__ import print_function
from apiclient.discovery import build
from httplib2 import Http
from oauth2client import file, client, tools

# Setup the Gmail API
SCOPES = 'https://www.googleapis.com/auth/gmail.readonly'
store = file.Storage('token.json')
creds = store.get()
if not creds or creds.invalid:
    flow = client.flow_from_clientsecrets('credentials.json', SCOPES)
    creds = tools.run_flow(flow, store)
service = build('gmail', 'v1', http=creds.authorize(Http()))

# Call the Gmail API
results = service.users().labels().list(userId='me').execute()
labels = results.get('labels', [])
if not labels:
    print('No labels found.')
else:
    print('Labels:')
    for label in labels:
        print(label['name'])