I want to stream data to azure block blob with python. The code below creates the blob but ends up with zero bytes. How can I make this work?
import io
import struct
from azure.storage.blob import BlockBlobService
storage = BlockBlobService('acct-xxx', 'key-xxx')
stream = io.BytesIO()
storage.create_blob_from_stream("mycontainer", "myblob", stream)
stream.write(struct.pack("d", 12.34))
stream.write(struct.pack("d", 56.78))
stream.close()
It seems that you've missed the key line of code：
stream.seek(0)
I set the stream's Position property to 0 then your code works.
import io
import struct
from azure.storage.blob import BlockBlobService
storage = BlockBlobService('acct-xxx', 'key-xxx')
stream = io.BytesIO()
stream.write(struct.pack("d", 12.34))
stream.write(struct.pack("d", 56.78))
stream.seek(0)
storage.create_blob_from_stream("mycontainer", "myblob", stream)
stream.close()
You could refer to this thread Azure storage: Uploaded files with size zero bytes.
I recommend using smart_open.
from smart_open import open
# stream from Azure Blob Storage
with open('azure://my_container/my_file.txt') as fin:
for line in fin:
print(line)
# stream content *into* Azure Blob Storage (write mode):
with open('azure://my_container/my_file.txt', 'wb') as fout:
fout.write(b'hello world')
