Help to solve the error : Cannot upload a blob after already uploading via url

[havy211]

Hi, I need the help of the community to understand this error: 

      "<Response [500]> Cannot upload a blob after already uploading via url".

The link that I am following as reference: Submission Comments - Canvas LMS REST API Documentation 

That happened when I tried to upload a file as comment to the canvas.

import requests
import os

def upload_file(self, url):
    with open(url, 'rb') as f:
        file_content = f.read()
    return file_content
def upload_jn_to_canvas(self😞

   # Step 1 - tell Canvas you want to upload a file
   post_api_url = '/api/v1/courses/:course_id/assignments/:assignment_id/submissions/:user_id/comments/files'

   session = requests.Session()
   session.headers = {'Authorization': 'Bearer {0}'.format(self.token)}
   response = session.post(post_api_url,
                        data={
                            'name': name_file,
                            'size': os.path.getsize(jupyter_notebook_file),
                            'parent_folder_path': '/',
                            'content-type': 'binary/octet-stream'
                        })

   response.raise_for_status()
   print('Session Headers: ', session.headers)
   print('Post URL: ', post_api_url)
   print(response.json())

   # Step 2 - upload file
   parameters = list(response.json()['upload_params'].items())
   parameters.append((u'file', self.upload_file(jupyter_notebook_file)))

   response2 = requests.post(response.json()['upload_url'], files=parameters)
   response2.raise_for_status()
   print(response2.json())
   print(response2)

[kona]

 @havy211 , greetings! Due to the technical nature of this question I'm going to share it with the Canvas Developers‌ in the Community to see if they can help! You might also consider joining this group so you'll have access to their resources and information!

Kona

[Robbie_Grant]

 @havy211 ,

Were you able to find an answer to your question? I am going to go ahead and mark this question as answered because there hasn't been any more activity in a while so I assume that you have the information that you need. If you still have a question about this or if you have information that you would like to share with the community, by all means, please do come back and leave a comment.  Also, if this question has been answered by one of the previous replies, please feel free to mark that answer as correct.

Robbie

[daanpareit]

I had the same issue in a python script with 'requests' module. You don't need to manually specify the additional 'file' argument, as stated in the API doc, but only use the 'files' option in the requests.post which will do this for you:

with open('myfigure.jpg', 'rb') as img:

    requests.post(

        response.json()['upload_url'],

        data=response.json()['upload_params'],

        files={'image': ('myfigure.jpg',img,'multipart/form-data') },

    )