Blobs / Objects#

Create / interact with Google Cloud Storage blobs.

class gcloud.storage.blob.Blob(name, bucket, chunk_size=None)[source]#

Bases: gcloud.storage._helpers._PropertyMixin

A wrapper around Cloud Storage’s concept of an Object.

Parameters:
  • name (string) – The name of the blob. This corresponds to the unique path of the object in the bucket.
  • bucket (gcloud.storage.bucket.Bucket) – The bucket to which this blob belongs.
  • chunk_size (integer) – The size of a chunk of data whenever iterating (1 MB). This must be a multiple of 256 KB per the API specification.
acl#

Create our ACL on demand.

cache_control#

HTTP ‘Cache-Control’ header for this object.

See: https://tools.ietf.org/html/rfc7234#section-5.2 and
https://cloud.google.com/storage/docs/json_api/v1/objects

If the property is not set locally, returns None.

Return type:string or NoneType
chunk_size#

Get the blob’s default chunk size.

Return type:integer or NoneType
Returns:The current blob’s chunk size, if it is set.
client#

The client bound to this blob.

component_count#

Number of underlying components that make up this object.

See: https://cloud.google.com/storage/docs/json_api/v1/objects

Return type:integer or NoneType
Returns:The component count (in case of a composed object) or None if the property is not set locally. This property will not be set on objects not created via compose.
content_disposition#

HTTP ‘Content-Disposition’ header for this object.

See: https://tools.ietf.org/html/rfc6266 and
https://cloud.google.com/storage/docs/json_api/v1/objects

If the property is not set locally, returns None.

Return type:string or NoneType
content_encoding#

HTTP ‘Content-Encoding’ header for this object.

See: https://tools.ietf.org/html/rfc7231#section-3.1.2.2 and
https://cloud.google.com/storage/docs/json_api/v1/objects

If the property is not set locally, returns None.

Return type:string or NoneType
content_language#

HTTP ‘Content-Language’ header for this object.

See: http://tools.ietf.org/html/bcp47 and
https://cloud.google.com/storage/docs/json_api/v1/objects

If the property is not set locally, returns None.

Return type:string or NoneType
content_type#

HTTP ‘Content-Type’ header for this object.

See: https://tools.ietf.org/html/rfc2616#section-14.17 and
https://cloud.google.com/storage/docs/json_api/v1/objects

If the property is not set locally, returns None.

Return type:string or NoneType
crc32c#

CRC32C checksum for this object.

See: http://tools.ietf.org/html/rfc4960#appendix-B and
https://cloud.google.com/storage/docs/json_api/v1/objects

If the property is not set locally, returns None.

Return type:string or NoneType
delete(client=None)[source]#

Deletes a blob from Cloud Storage.

Parameters:client (gcloud.storage.client.Client or NoneType) – Optional. The client to use. If not passed, falls back to the client stored on the blob’s bucket.
Return type:Blob
Returns:The blob that was just deleted.
Raises:gcloud.exceptions.NotFound (propagated from gcloud.storage.bucket.Bucket.delete_blob()).
download_as_string(client=None)[source]#

Download the contents of this blob as a string.

Parameters:client (gcloud.storage.client.Client or NoneType) – Optional. The client to use. If not passed, falls back to the client stored on the blob’s bucket.
Return type:bytes
Returns:The data stored in this blob.
Raises:gcloud.exceptions.NotFound
download_to_file(file_obj, client=None)[source]#

Download the contents of this blob into a file-like object.

Note

If the server-set property, media_link, is not yet initialized, makes an additional API request to load it.

Parameters:
  • file_obj (file) – A file handle to which to write the blob’s data.
  • client (gcloud.storage.client.Client or NoneType) – Optional. The client to use. If not passed, falls back to the client stored on the blob’s bucket.
Raises:

gcloud.exceptions.NotFound

download_to_filename(filename, client=None)[source]#

Download the contents of this blob into a named file.

Parameters:
  • filename (string) – A filename to be passed to open.
  • client (gcloud.storage.client.Client or NoneType) – Optional. The client to use. If not passed, falls back to the client stored on the blob’s bucket.
Raises:

gcloud.exceptions.NotFound

etag#

Retrieve the ETag for the object.

See: http://tools.ietf.org/html/rfc2616#section-3.11 and
https://cloud.google.com/storage/docs/json_api/v1/objects
Return type:string or NoneType
Returns:The blob etag or None if the property is not set locally.
exists(client=None)[source]#

Determines whether or not this blob exists.

Parameters:client (gcloud.storage.client.Client or NoneType) – Optional. The client to use. If not passed, falls back to the client stored on the blob’s bucket.
Return type:boolean
Returns:True if the blob exists in Cloud Storage.
generate_signed_url(expiration, method='GET', content_type=None, generation=None, response_disposition=None, response_type=None, client=None, credentials=None)[source]#

Generates a signed URL for this blob.

Note

If you are on Google Compute Engine, you can’t generate a signed URL. Follow Issue 922 for updates on this. If you’d like to be able to generate a signed URL from GCE, you can use a standard service account from a JSON file rather than a GCE service account.

If you have a blob that you want to allow access to for a set amount of time, you can use this method to generate a URL that is only valid within a certain time period.

This is particularly useful if you don’t want publicly accessible blobs, but don’t want to require users to explicitly log in.

Parameters:
  • expiration (int, long, datetime.datetime, datetime.timedelta) – When the signed URL should expire.
  • method (str) – The HTTP verb that will be used when requesting the URL.
  • content_type (str) – (Optional) The content type of the object referenced by resource.
  • generation (str) – (Optional) A value that indicates which generation of the resource to fetch.
  • response_disposition (str) – (Optional) Content disposition of responses to requests for the signed URL. For example, to enable the signed URL to initiate a file of blog.png, use the value 'attachment; filename=blob.png'.
  • response_type (str) – (Optional) Content type of responses to requests for the signed URL. Used to over-ride the content type of the underlying blob/object.
  • client (gcloud.storage.client.Client or NoneType) – (Optional) The client to use. If not passed, falls back to the client stored on the blob’s bucket.
  • credentials (oauth2client.client.OAuth2Credentials or NoneType) – (Optional) The OAuth2 credentials to use to sign the URL. Defaults to the credentials stored on the client used.
Return type:

str

Returns:

A signed URL you can use to access the resource until expiration.

generation#

Retrieve the generation for the object.

See: https://cloud.google.com/storage/docs/json_api/v1/objects

Return type:integer or NoneType
Returns:The generation of the blob or None if the property is not set locally.
id#

Retrieve the ID for the object.

See: https://cloud.google.com/storage/docs/json_api/v1/objects

Return type:string or NoneType
Returns:The ID of the blob or None if the property is not set locally.
make_public(client=None)[source]#

Make this blob public giving all users read access.

Parameters:client (gcloud.storage.client.Client or NoneType) – Optional. The client to use. If not passed, falls back to the client stored on the blob’s bucket.
md5_hash#

MD5 hash for this object.

See: http://tools.ietf.org/html/rfc4960#appendix-B and
https://cloud.google.com/storage/docs/json_api/v1/objects

If the property is not set locally, returns None.

Return type:string or NoneType

Retrieve the media download URI for the object.

See: https://cloud.google.com/storage/docs/json_api/v1/objects

Return type:string or NoneType
Returns:The media link for the blob or None if the property is not set locally.
metadata#

Retrieve arbitrary/application specific metadata for the object.

See: https://cloud.google.com/storage/docs/json_api/v1/objects

Return type:dict or NoneType
Returns:The metadata associated with the blob or None if the property is not set locally.
metageneration#

Retrieve the metageneration for the object.

See: https://cloud.google.com/storage/docs/json_api/v1/objects

Return type:integer or NoneType
Returns:The metageneration of the blob or None if the property is not set locally.
owner#

Retrieve info about the owner of the object.

See: https://cloud.google.com/storage/docs/json_api/v1/objects

Return type:dict or NoneType
Returns:Mapping of owner’s role/ID. If the property is not set locally, returns None.
path#

Getter property for the URL path to this Blob.

Return type:string
Returns:The URL path to this Blob.
static path_helper(bucket_path, blob_name)[source]#

Relative URL path for a blob.

Parameters:
  • bucket_path (string) – The URL path for a bucket.
  • blob_name (string) – The name of the blob.
Return type:

string

Returns:

The relative URL path for blob_name.

public_url#

The public URL for this blob’s object.

Return type:string
Returns:The public URL for this blob.

Retrieve the URI for the object.

See: https://cloud.google.com/storage/docs/json_api/v1/objects

Return type:string or NoneType
Returns:The self link for the blob or None if the property is not set locally.
size#

Size of the object, in bytes.

See: https://cloud.google.com/storage/docs/json_api/v1/objects

Return type:integer or NoneType
Returns:The size of the blob or None if the property is not set locally.
storage_class#

Retrieve the storage class for the object.

See: https://cloud.google.com/storage/docs/storage-classes https://cloud.google.com/storage/docs/nearline-storage https://cloud.google.com/storage/docs/durable-reduced-availability

Return type:string or NoneType
Returns:If set, one of “STANDARD”, “NEARLINE”, or “DURABLE_REDUCED_AVAILABILITY”, else None.
time_deleted#

Retrieve the timestamp at which the object was deleted.

See: https://cloud.google.com/storage/docs/json_api/v1/objects

Return type:datetime.datetime or NoneType
Returns:Datetime object parsed from RFC3339 valid timestamp, or None if the property is not set locally. If the blob has not been deleted, this will never be set.
updated#

Retrieve the timestamp at which the object was updated.

See: https://cloud.google.com/storage/docs/json_api/v1/objects

Return type:datetime.datetime or NoneType
Returns:Datetime object parsed from RFC3339 valid timestamp, or None if the property is not set locally.
upload_from_file(file_obj, rewind=False, size=None, content_type=None, num_retries=6, client=None)[source]#

Upload the contents of this blob from a file-like object.

The content type of the upload will either be - The value passed in to the function (if any) - The value stored on the current blob - The default value of ‘application/octet-stream’

Note

The effect of uploading to an existing blob depends on the “versioning” and “lifecycle” policies defined on the blob’s bucket. In the absence of those policies, upload will overwrite any existing contents.

See the object versioning and lifecycle API documents for details.

Parameters:
  • file_obj (file) – A file handle open for reading.
  • rewind (boolean) – If True, seek to the beginning of the file handle before writing the file to Cloud Storage.
  • size (int) – The number of bytes to read from the file handle. If not provided, we’ll try to guess the size using os.fstat(). (If the file handle is not from the filesystem this won’t be possible.)
  • content_type (string or NoneType) – Optional type of content being uploaded.
  • num_retries (integer) – Number of upload retries. Defaults to 6.
  • client (gcloud.storage.client.Client or NoneType) – Optional. The client to use. If not passed, falls back to the client stored on the blob’s bucket.
Raises:

ValueError if size is not passed in and can not be determined

upload_from_filename(filename, content_type=None, client=None)[source]#

Upload this blob’s contents from the content of a named file.

The content type of the upload will either be - The value passed in to the function (if any) - The value stored on the current blob - The value given by mimetypes.guess_type

Note

The effect of uploading to an existing blob depends on the “versioning” and “lifecycle” policies defined on the blob’s bucket. In the absence of those policies, upload will overwrite any existing contents.

See the object versioning and lifecycle API documents for details.

Parameters:
  • filename (string) – The path to the file.
  • content_type (string or NoneType) – Optional type of content being uploaded.
  • client (gcloud.storage.client.Client or NoneType) – Optional. The client to use. If not passed, falls back to the client stored on the blob’s bucket.
upload_from_string(data, content_type='text/plain', client=None)[source]#

Upload contents of this blob from the provided string.

Note

The effect of uploading to an existing blob depends on the “versioning” and “lifecycle” policies defined on the blob’s bucket. In the absence of those policies, upload will overwrite any existing contents.

See the object versioning and lifecycle API documents for details.

Parameters:
  • data (bytes or text) – The data to store in this blob. If the value is text, it will be encoded as UTF-8.
  • content_type (string) – Optional type of content being uploaded. Defaults to 'text/plain'.
  • client (gcloud.storage.client.Client or NoneType) – Optional. The client to use. If not passed, falls back to the client stored on the blob’s bucket.