import os.path
from google.auth.transport.requests import Request
from google.oauth2.credentials import Credentials
from google_auth_oauthlib.flow import InstalledAppFlow
from googleapiclient.discovery import build
# If modifying these scopes, delete the file token.json.
SCOPES = ['https://www.googleapis.com/auth/gmail.readonly']
def authenticate():
"""Shows basic usage of the Gmail API.
Lists the user's Gmail labels.
"""
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:
if not os.path.exists('credentials.json'):
raise FileNotFoundError("credentials.json not found. Please download it from Google Cloud Console.")
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())
print("Authentication successful! token.json created.")
service = build('gmail', 'v1', credentials=creds)
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'])
if __name__ == '__main__':
authenticate()
