You can still miss attachments by following @Ilya V. Schurov or @Cam T answers, the reason is because the email structure can be different based on the mimeType.
Inspired by this answer, here is my approach to the problem.
import base64
from apiclient import errors
def GetAttachments(service, user_id, msg_id, store_dir=""):
"""Get and store attachment from Message with given id.
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.
msg_id: ID of Message containing attachment.
store_dir: The directory used to store attachments.
"""
try:
message = service.users().messages().get(userId=user_id, id=msg_id).execute()
parts = [message['payload']]
while parts:
part = parts.pop()
if part.get('parts'):
parts.extend(part['parts'])
if part.get('filename'):
if 'data' in part['body']:
file_data = base64.urlsafe_b64decode(part['body']['data'].encode('UTF-8'))
#self.stdout.write('FileData for %s, %s found! size: %s' % (message['id'], part['filename'], part['size']))
elif 'attachmentId' in part['body']:
attachment = service.users().messages().attachments().get(
userId=user_id, messageId=message['id'], id=part['body']['attachmentId']
).execute()
file_data = base64.urlsafe_b64decode(attachment['data'].encode('UTF-8'))
#self.stdout.write('FileData for %s, %s found! size: %s' % (message['id'], part['filename'], attachment['size']))
else:
file_data = None
if file_data:
#do some staff, e.g.
path = ''.join([store_dir, part['filename']])
with open(path, 'w') as f:
f.write(file_data)
except errors.HttpError as error:
print 'An error occurred: %s' % error