emailfunctions.py

import os
import pickle
# Gmail API utils
from googleapiclient.discovery import build
from google_auth_oauthlib.flow import InstalledAppFlow
from google.auth.transport.requests import Request
# for encoding/decoding messages in base64
from base64 import urlsafe_b64decode, urlsafe_b64encode
# for dealing with attachement MIME types
from email.mime.text import MIMEText
from email.mime.multipart import MIMEMultipart
from email.mime.image import MIMEImage
from email.mime.audio import MIMEAudio
from email.mime.base import MIMEBase
from mimetypes import guess_type as guess_mime_type

# Request all access (permission to read/send/receive emails, manage the inbox, and more)
SCOPES = ['https://mail.google.com/']
our_email = '' # Your email
TOKEN_PATH = '' # Path where you want to save token file.
CREDENTIALS_PATH = '' # This is the location of the downloaded Gmail credentials.
FILE_PATH = '' # Where you want to save attachment files.

def gmail_authenticate():
    creds = None
    # the file token.pickle 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_PATH):
        with open(TOKEN_PATH, "rb") as token:
            creds = pickle.load(token)
    # if there are no (valid) credentials availablle, 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_PATH, SCOPES)
            creds = flow.run_local_server(port=0)
        # save the credentials for the next run
        with open(TOKEN_PATH, "wb") as token:
            pickle.dump(creds, token)
    return build('gmail', 'v1', credentials=creds)

def build_message(destination, obj, body, attachments=[]):
    if not attachments: # no attachments given
        message = MIMEText(body)
        message['to'] = destination
        message['from'] = our_email
        message['subject'] = obj
    else:
        message = MIMEMultipart()
        message['to'] = destination
        message['from'] = our_email
        message['subject'] = obj
        message.attach(MIMEText(body))
        for filename in attachments:
            add_attachment(message, filename)
    return {'raw': urlsafe_b64encode(message.as_bytes()).decode()}

def send_message(service, destination, obj, body, attachments=[]):
    return service.users().messages().send(
      userId="me",
      body=build_message(destination, obj, body, attachments)
    ).execute()

def search_messages(service, query):
    result = service.users().messages().list(userId='me',q=query).execute()
    messages = [ ]
    if 'messages' in result:
        messages.extend(result['messages'])
    while 'nextPageToken' in result:
        page_token = result['nextPageToken']
        result = service.users().messages().list(userId='me',q=query, pageToken=page_token).execute()
        if 'messages' in result:
            messages.extend(result['messages'])
    return messages

import base64

def GetAttachments(service, msg_id, user_id='me'):
    """Get and store attachment from Message with given id.

    :param service: Authorized Gmail API service instance.
    :param user_id: User's email address. The special value "me" can be used to indicate the authenticated user.
    :param msg_id: ID of Message containing attachment.
    """
    try:
        message = service.users().messages().get(userId=user_id, id=msg_id).execute()

        for part in message['payload']['parts']:
            if part['filename']:
                if 'data' in part['body']:
                    data = part['body']['data']
                else:
                    att_id = part['body']['attachmentId']
                    att = service.users().messages().attachments().get(userId=user_id, messageId=msg_id,id=att_id).execute()
                    data = att['data']
                file_data = base64.urlsafe_b64decode(data.encode('UTF-8'))
                path = part['filename']

                with open(FILE_PATH + path, 'wb') as f:
                    f.write(file_data)
        return FILE_PATH + path

    except:
        print('An error occurred: %s' % error)