yc25744 / Python_SendEmail_gmail

Gmail_API

There are two ways to send email using the Gmail API

1. You can send it directly using the **messages.send** method.
2. You can send it from a draft, using the **drafts.send** method.

On this project repo, I will use messages.send

Creating messages

def create_message(sender, to, subject, message_text):
  """Create a message for an email.

  Args:
    sender: Email address of the sender.
    to: Email address of the receiver.
    subject: The subject of the email message.
    message_text: The text of the email message.

  Returns:
    An object containing a base64url encoded email object.
  """
  message = MIMEText(message_text)
  message['to'] = to
  message['from'] = sender
  message['subject'] = subject
  return {'raw': base64.urlsafe_b64encode(message.as_string())}

creating messages with attachments

def create_message_with_attachment(
sender, to, subject, message_text, file):
"""Create a message for an email.

  Args:
    sender: Email address of the sender.
    to: Email address of the receiver.
    subject: The subject of the email message.
    message_text: The text of the email message.
    file: The path to the file to be attached.

  Returns:
    An object containing a base64url encoded email object.
  """
  message = MIMEMultipart()
  message['to'] = to
  message['from'] = sender
  message['subject'] = subject

  msg = MIMEText(message_text)
  message.attach(msg)

  content_type, encoding = mimetypes.guess_type(file)

  if content_type is None or encoding is not None:
    content_type = 'application/octet-stream'
  main_type, sub_type = content_type.split('/', 1)
  if main_type == 'text':
    fp = open(file, 'rb')
    msg = MIMEText(fp.read(), _subtype=sub_type)
    fp.close()
  elif main_type == 'image':
    fp = open(file, 'rb')
    msg = MIMEImage(fp.read(), _subtype=sub_type)
    fp.close()
  elif main_type == 'audio':
    fp = open(file, 'rb')
    msg = MIMEAudio(fp.read(), _subtype=sub_type)
    fp.close()
  else:
    fp = open(file, 'rb')
    msg = MIMEBase(main_type, sub_type)
    msg.set_payload(fp.read())
    fp.close()
  filename = os.path.basename(file)
  msg.add_header('Content-Disposition', 'attachment', filename=filename)
  message.attach(msg)

  return {'raw': base64.urlsafe_b64encode(message.as_string())}

Sending messages

def send_message(service, user_id, message):
"""Send an email message.

Args:
service: Authorized Gmail API service instance.
user_id: User's email address. The special value "me"
can be used to indicate the authenticated user.
message: Message to be sent.

Returns:
Sent Message.
"""
  try:
    message = (service.users().messages().send(userId=user_id, body=message)
               .execute())
    print 'Message Id: %s' % message['id']
    return message
  except errors.HttpError, error:
    print 'An error occurred: %s' % error

Set up for the Python

Step 1: Install the Google CLient library

pip install --upgrade google-api-python-client google-auth-httplib2 google-auth-oauthlib

Step 2: Configure the sample

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/gmail.readonly']

def main():
    """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:
            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('gmail', 'v1', credentials=creds)

    # 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'])

if __name__ == '__main__':
    main()