使用 Python 从 gmail api 下载附件

Question

我正在尝试使用 python 从 gmail 下载附件，但无法从邮件中获取附件 ID。请在下面找到我的代码

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
from googleapiclient.errors import HttpError


def get_gmail_service():
    SCOPES = ['https://www.googleapis.com/auth/gmail.readonly']
    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())

        try:
            # Call the Gmail API
            service = build('gmail', 'v1', credentials=creds)
            return service

        except HttpError as error:
        # TODO(developer) - Handle errors from gmail API.
            print(f'An error occurred: {error}')

def get_email_list():
    service = get_gmail_service()
    results = service.users().messages().list(userId='me',q='from:[email protected] is:read').execute()
    # print(results.get('messages',[])[0].get('id',[]))
    return results.get('messages', [])[0].get('id', [])
    # return results.get('messages',[])

def get_email_content(message_id):
    service = get_gmail_service()
    attach = service.users().messages().get(userId='me',id =message_id).execute()
    attach_id = attach.get('payloads',[]).get('parts',[]).get('body',[])
    data = service.users().messages().get(userId='me',id = message_id).execute()
    return attach_id

if __name__ == '__main__':
    # get_email_list()
    print(get_email_content(get_email_list()))

请更正我的代码，以便我可以使用 gmail api 下载附件。

Answer 1

这段代码有两个主要问题。

1. results.get() 方法返回 消息 或 MessagePart 对象。因此，您只需使用一次 get() 方法即可获取完整的对象，然后您就可以定位您想要的对象的特定部分。

   例如。 results.get('messages', [])[0]['id']

2. 电子邮件的有效负载可以是多部分的（这意味着“部分”将是 <代码>MessagePart 对象）。因此，我们需要迭代以获得包含文件的“消息部分”。在本例中，我们可以检查 MessagePart 对象是否有文件名。

    parts = attach.get('payload',[])['parts']
    
    for i in parts:
        if( i['filename'] ):
            return i['body']['attachmentId'] 

So After taking care of these two issues, this is the new code:

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
from googleapiclient.errors import HttpError


def get_gmail_service():
    SCOPES = ['https://www.googleapis.com/auth/gmail.readonly']
    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())

        try:
            # Call the Gmail API
            service = build('gmail', 'v1', credentials=creds)
            return service

        except HttpError as error:
        # TODO(developer) - Handle errors from gmail API.
            print(f'An error occurred: {error}')

def get_email_list():
    service = get_gmail_service()
    results = service.users().messages().list(userId='me',q='from:[email protected] is:read').execute()
    # print(results.get('messages',[])[0]['id'] )
    return results.get('messages', [])[0]['id']
    # return results.get('messages',[])

def get_email_content(message_id):
    print(message_id)
    service = get_gmail_service()
    data = service.users().messages().get(userId='me',id = message_id).execute()

    attach = service.users().messages().get(userId='me',id =message_id).execute()
    parts = attach.get('payload',[])['parts']
    
    for i in parts:
        if( i['filename'] ):
            return i['body']['attachmentId'] 

if __name__ == '__main__':
    # get_email_list()
    print(get_email_content(get_email_list()))

我希望这能回答您的问题！