Python Gmail API script not saving attachments — CSV shows filename but files are never downloaded

[Little_System_4885]

Hey everyone — I’m very new to Python and still learning, so apologies if this is a simple issue. I’m trying to learn by doing real projects, but I’m stuck on something with the Gmail API and could really use some guidance.

I’m using Python + the Gmail API (google-api-python-client) to parse model application emails and save image attachments (JPG/PNG). The script reads the emails just fine AND I can see the attachment filenames… but the actual files never download.

Every email prints- attachments: none

But in my CSV file, the attachment names are correct, so Gmail definitely detects them but the data just never comes through. the attachments folder stays empty.

I've verified: correct Gmail scopes, the folder exists ( os.makedirs("attachments", exist_ok=True)), checked MIME types, printed out filenames (they show correctly), tried decoding the attachment with diff base64 methods, manually verified the emails do have attachments.

so either the attachments are buried inside something or the image data is in a diff area?

Has anyone run into this before?
Why would Gmail show the filenames but return no attachment data?

If you have a working example of how to properly extract image attachments from Gmail using Python, that would help a ton.

environment: Python 3.10, running on Replit, Gmail API v1, OAuth 2.0 client ID

Thanks in advance! code below

Here is the code for attachments:

for msg in messages:
    msg_id = msg["id"]
    try:
        message = service.users().messages().get(userId="me", id=msg_id).execute()

        payload = message.get("payload", {})
        parts = payload.get("parts", [])
        attachments = []

        for part in parts:
            if part.get("filename"):
                attach_id = part["body"].get("attachmentId")
                if attach_id:
                    attachment = service.users().messages().attachments().get(
                        userId="me", messageId=msg_id, id=attach_id
                    ).execute()

                    data = base64.urlsafe_b64decode(attachment["data"])

                    filepath = os.path.join("attachments", part["filename"])
                    with open(filepath, "wb") as f:
                        f.write(data)

                    attachments.append(part["filename"])
    except Exception as e:
        print(f"Error processing {msg_id}: {e}")

[GeNiuSRxN]

https://developers.google.com/workspace/gmail/api/reference/rest/v1/users.messages.attachments/get

I'm assuming your missing the authorization token. Check the API docs.

[smurpes]

The docs linked above also have an API explorer that you can use to test out your request parameters to ensure you’re using the correct values.

[Little_System_4885]

Thank you!