auth.py

from __future__ import print_function
import httplib2
import os
from apiclient import discovery
from oauth2client import client
from oauth2client import tools
from oauth2client.file import Storage

try:
    import argparse
    flags = argparse.ArgumentParser(parents=[tools.argparser]).parse_args()
except ImportError:
    flags = None


class auth:

    def __init__(self,SCOPES,CLIENT_SECRET_FILE,APPLICATION_NAME):
        self.SCOPES = SCOPES
        self.CLIENT_SECRET_FILE = CLIENT_SECRET_FILE
        self.APPLICATION_NAME = APPLICATION_NAME

    def get_credential(self):
        cwd_dir = os.getcwd()
        #home_dir = os.path.expanduser('~')
        credential_dir = os.path.join(cwd_dir, '.credentials')

        if not os.path.exists(credential_dir):
            os.makedirs(credential_dir)

        credential_path = os.path.join(credential_dir, 'google.drive.credential.json')
        store = Storage(credential_path)
        credentials = store.get()

        if not credentials or credentials.invalid:
            flow = client.flow_from_clientsecrets(self.CLIENT_SECRET_FILE, self.SCOPES)
            flow.user_agent = self.APPLICATION_NAME

            if flags:
                credentials = tools.run_flow(flow, store, flags)
            else:
                credentials = tools.run(flow, store)
            print('String credentials to' + credential_path)
        return credentials