python azure blob readinto with requests stream upload - python-3.x

Question

I have videos saved in azure blob storage and i want to upload them into facebook. Facebook video upload is a multipart/form-data post request. Ordinary way of doing this is download azure blob as bytes using readall() method in azure python sdk and set it in requests post data as follows.
# download video from azure blob
video = BlobClient.from_connection_string(AZURE_STORAGE_CONNECTION_STRING,
AZURE_CONTAINER_NAME,
f"{folder_id}/{file_name}")
video = video.download_blob().readall()
# upload video to facebook
url = f"{API_VIDEO_URL}/{page_id}/videos"
params = {
"upload_phase": "transfer",
"upload_session_id": session_id,
"start_offset": start_offset,
"access_token": access_token
}
response = requests.post(url, params=params, files={"video_file_chunk": video})
Bytes of the file is loaded into the memory and this is not good for larger files. There is a method in azure sdk readinto(stream) that downloads the file into a stream. Is there a way to connect requests streaming upload and readinto() method. Or is there a another way to upload the file directly from blob storage?

Answer 1

Regarding how to upload video in chunk with stream, please refer to the following code
from azure.storage.blob import BlobClient
import io
from requests_toolbelt import MultipartEncoder
import requests
blob_poperties=blob.get_blob_properties()
blob_size=blob_poperties.size # the blob size
access_token=''
session_id='675711696358783'
chunk_size= 1024*1024 #the chunk size
bytesRemaining = blob_size
params = {
"upload_phase": "transfer",
"upload_session_id": session_id,
"start_offset": 0,
"access_token": access_token
}
url="https://graph-video.facebook.com/v7.0/101073631699517/videos"
bytesToFetch=0
start=0 # where to start downlaoding
while bytesRemaining>0 :
with io.BytesIO() as f:
if bytesRemaining < chunk_size:
bytesToFetch= bytesRemaining
else:
bytesToFetch=chunk_size
print(bytesToFetch)
print(start)
downloader =blob.download_blob(start,bytesToFetch)
b=downloader.readinto(f)
print(b)
m = MultipartEncoder(
fields={'video_file_chunk':('file',f) }
)
r =requests.post(url, params=params, headers={'Content-Type': m.content_type}, data=m)
s=r.json()
print(s)
start =int(s['start_offset'])
bytesRemaining -=int(s['start_offset'])
params['start_offset']=start
print(params)
# end uplaod
params['upload_phase']= 'finish'
r=requests.post(url, params=params)
print(r)