# Copyright 2018 Google LLC

#

# Licensed under the Apache License, Version 2.0 (the "License");

# you may not use this file except in compliance with the License.

# You may obtain a copy of the License at

#

# http://www.apache.org/licenses/LICENSE-2.0

#

# Unless required by applicable law or agreed to in writing, software

# distributed under the License is distributed on an "AS IS" BASIS,

# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

# See the License for the specific language governing permissions and

# limitations under the License.

# [START docs_quickstart]

from __future__ import print_function

import os.path

from googleapiclient.discovery import build

from google_auth_oauthlib.flow import InstalledAppFlow

from google.auth.transport.requests import Request

from google.oauth2.credentials import Credentials

# If modifying these scopes, delete the file token.json.

SCOPES = ['https://www.googleapis.com/auth/documents.readonly']

# The ID of a sample document.

DOCUMENT_ID = '195j9eDD3ccgjQRttHhJPymLJUCOUjs-jmwTrekvdjFE'

def main():

"""Shows basic usage of the Docs API.

Prints the title of a sample document.

"""

creds = None

# The file token.json stores the user's access and refresh tokens, and is

# created automatically when the authorization flow completes for the first

# time.

if os.path.exists('token.json'):

creds = Credentials.from_authorized_user_file('token.json', SCOPES)

# If there are no (valid) credentials available, let the user log in.

if not creds or not creds.valid:

if creds and creds.expired and creds.refresh_token:

creds.refresh(Request())

else:

flow = InstalledAppFlow.from_client_secrets_file(

'credentials.json', SCOPES)

creds = flow.run_local_server(port=0)

# Save the credentials for the next run

with open('token.json', 'w') as token:

token.write(creds.to_json())

service = build('docs', 'v1', credentials=creds)

# Retrieve the documents contents from the Docs service.

document = service.documents().get(documentId=DOCUMENT_ID).execute()

print('The title of the document is: {}'.format(document.get('title')))

if __name__ == '__main__':

main()

# [END docs_quickstart]