Retrieving email attachments via Gmail API

Other Questions Gmail
1

Hey everyone, I’m trying to get attachments from my Gmail using their API. I’m working with the Google Python API client, but I’m running into some issues.

I tried using the code from the official docs, but it’s not working. I keep getting an error about ‘Resource’ not having a ‘user’ attribute. Here’s what I’m doing:

result = gmail_service.users().messages().get(userId='me', id=message_id).execute()

This works, but when I try to access the attachment data, it’s not there. I’m looping through the parts like this:

for part in result['payload']['parts']:
    if 'body' in part and 'data' in part['body']:
        # Do something with attachment
        pass
    else:
        print('No attachment data found')

But the ‘data’ key is always missing. Am I doing something wrong? Has anyone successfully downloaded attachments this way? Any help would be appreciated!

2

yo, i’ve dealt with this before. the trick is to use the ‘raw’ format when fetching messages. try this:

result = gmail_service.users().messages().get(userId=‘me’, id=message_id, format=‘raw’).execute()

then you gotta decode the raw message and parse it. it’s a bit more work, but it’ll give you all the attachment data you need. good luck!

3

I’ve worked with the Gmail API for attachment retrieval before, and I can share some insights. The issue you’re facing is likely due to the message not being fully fetched. Try modifying your initial request to include the full message content:

result = gmail_service.users().messages().get(userId='me', id=message_id, format='full').execute()

This should fetch the complete message, including attachment data. Also, consider checking for the ‘attachmentId’ in the parts. If present, you’ll need to make an additional API call to fetch the actual attachment data:

if 'attachmentId' in part['body']:
    attachment = gmail_service.users().messages().attachments().get(userId='me', messageId=message_id, id=part['body']['attachmentId']).execute()
    file_data = base64.urlsafe_b64decode(attachment['data'].encode('UTF-8'))
    # Now you can save or process file_data

Hope this helps you resolve the attachment retrieval issue.

4

I’ve encountered similar issues when working with the Gmail API for attachments. One thing that helped me was to check the ‘mimeType’ of each part since attachments are sometimes nested within multipart messages.

Try modifying your loop like this:

for part in result['payload']['parts']:
    if part['mimeType'].startswith('multipart'):
        # Recursively check nested parts
        for subpart in part['parts']:
            if subpart['filename']:
                # This is likely an attachment
                attachment_id = subpart['body']['attachmentId']
                # Fetch attachment data here
    elif part['filename']:
        # This is a non-nested attachment
        attachment_id = part['body']['attachmentId']
        # Fetch attachment data here

Also, make sure you’re using the correct scopes when authenticating. You need ‘https://www.googleapis.com/auth/gmail.readonly’ at minimum for reading attachments. Remember to handle potential exceptions as network issues or changes in the API can sometimes lead to unexpected errors. Good luck with your project!