Upload session api creating empty files

ankit_goyal

import requests
import json

class DropboxUtil:
    _token = None
    _logger = None
    UPLOAD_SIZE = 149 * 1024 * 1024

    def __init__(self, token):
        DropboxUtil._token = "Bearer " + token

    def upload(self, data = None):
        """
        Start a new upload session and upload the requested content to desired directory on Dropbox.
        """
        try:
            upload_url = "https://content.dropboxapi.com/2/files/upload_session/start"

            api_arguments = {
"close" : False
            }

            upload_response = requests.post(upload_url, headers = {
"Authorization" : self._token,
"Dropbox-API-Arg" : json.dumps(api_arguments),
"Content-Type" : "application/octet-stream"
            })

if "session_id" in upload_response.json():
                return upload_response.json()['session_id']
else:
                raise Exception("Unable to upload file to Dropbox")
except Exception as e:
            raise e

def _append_to_upload(self, session_id, offset, data):
        try:
            append_uri = "https://content.dropboxapi.com/2/files/upload_session/append_v2"

            api_arguments = {
"cursor": {
"session_id": session_id,
"offset": offset
                },
"close": False
            }

            requests.post(append_uri, data, headers={
"Authorization" : self._token,
"Content-Type" : "application/octet-stream",
"Dropbox-API-Arg" : json.dumps(api_arguments)
            })
except Exception as e:
            raise e

def _finish_upload(self, filepath, offset, session_id):
        """
        Ends current upload session and creates the file with given filename. Offset is the total size if file in bytes.
        """
        try:
            finish_upload_url = "https://content.dropboxapi.com/2/files/upload_session/finish"

            api_arguments = {
"cursor": {
"session_id": session_id,
"offset": offset
                },
"commit": {
"path": filepath,
"mode": "add",
"autorename": True,
"mute": False,
"strict_conflict": False
                }
            }

            finish_response = requests.post(finish_upload_url, headers = {
"Authorization" : self._token,
"Content-Type" : "application/octet-stream",
"Dropbox-API-Arg" : json.dumps(api_arguments)
            })
print(finish_response.content)
except Exception as e:
            raise e

if __name__ == '__main__':
    db = DropboxUtil('<token>')
    session_id = db.upload()
    data = b'test_data'
    db._append_to_upload(session_id, len(data), data)
    db._finish_upload('/test11.txt', 0, session_id)  

 

Why does test11.txt is always created with no content ?

Greg-DB

I see from your code that you're only sending data with the append call. You can actually send data on any/all of the start, append, and finish calls, though it's not required. (Also, for small uploads like this, you don't need to use upload sessions at all, but I presume this is just for the sake of testing the code during development.)

Anyway, you are sending data with the append call, but you aren't checking if that call is succeeding. You should check the result and add some error handling around the append call. You can check success via the returned status code, and check the response body for more information.

I suspect the underlying issue is due to your "offset" handling, and is being obscured by the lack of response/error handling for the append call. Specifically, the "offset" you supply should be "The amount of data that has been uploaded so far" (for the upload session overall), not how much you're sending in the current request, as you appear to have in your code with `len(data)`.