StorageStreamDownloader Class

A streaming object to download from Azure Storage.

Inheritance

builtins.object

StorageStreamDownloader

Constructor

StorageStreamDownloader(clients=None, config=None, start_range=None, end_range=None, validate_content=None, encryption_options=None, max_concurrency=1, name=None, container=None, encoding=None, **kwargs)

Parameters

clients

default value: None

config

default value: None

start_range

default value: None

end_range

default value: None

validate_content

default value: None

encryption_options

default value: None

max_concurrency

default value: 1

name

default value: None

container

default value: None

encoding

default value: None

Variables

name

str

The name of the blob being downloaded.

container

str

The name of the container where the blob is.

properties

BlobProperties

The properties of the blob being downloaded. If only a range of the data is being downloaded, this will be reflected in the properties.

size

int

The size of the total data in the stream. This will be the byte range if specified, otherwise the total size of the blob.

Methods

chunks	Iterate over chunks in the download stream.
content_as_bytes	Download the contents of this file. This operation is blocking until all data is downloaded.
content_as_text	Download the contents of this blob, and decode as text. This operation is blocking until all data is downloaded.
download_to_stream	Download the contents of this blob to a stream.
readall	Download the contents of this blob. This operation is blocking until all data is downloaded. :rtype: bytes or str
readinto	Download the contents of this file to a stream.

chunks

Iterate over chunks in the download stream.

chunks() -> Iterator[bytes]

Return type

<xref:Iterator>[bytes]

Examples

Download a blob using chunks().

   # This returns a StorageStreamDownloader.
   stream = source_blob_client.download_blob()
   block_list = []

   # Read data in chunks to avoid loading all into memory at once
   for chunk in stream.chunks():
       # process your data (anything can be done here really. `chunk` is a byte array).
       block_id = str(uuid.uuid4())
       destination_blob_client.stage_block(block_id=block_id, data=chunk)
       block_list.append(BlobBlock(block_id=block_id))

content_as_bytes

Download the contents of this file.

This operation is blocking until all data is downloaded.

content_as_bytes(max_concurrency=1)

Parameters

max_concurrency

int

default value: 1

The number of parallel connections with which to download.

Return type

bytes

content_as_text

Download the contents of this blob, and decode as text.

This operation is blocking until all data is downloaded.

content_as_text(max_concurrency=1, encoding='UTF-8')

Parameters

max_concurrency

int

default value: 1

The number of parallel connections with which to download.

encoding

str

default value: UTF-8

Test encoding to decode the downloaded bytes. Default is UTF-8.

Return type

str

download_to_stream

Download the contents of this blob to a stream.

download_to_stream(stream, max_concurrency=1)

Parameters

stream

Required

The stream to download to. This can be an open file-handle, or any writable stream. The stream must be seekable if the download uses more than one parallel connection.

max_concurrency

default value: 1

Returns

The properties of the downloaded blob.

Return type

<xref:Any>

readall

Download the contents of this blob.

This operation is blocking until all data is downloaded. :rtype: bytes or str

readall() -> Union[bytes, str]

readinto

Download the contents of this file to a stream.

readinto(stream)

Parameters

stream

Required

The stream to download to. This can be an open file-handle, or any writable stream. The stream must be seekable if the download uses more than one parallel connection.

Returns

The number of bytes read.

Return type

int