The s3:, gs: and az: schemes

With uripath installed (pip install "objpath[uri]"), the URL of an object is a path:

from uripath import URIPath

URIPath("s3://data/reports/2026.csv")          # an S3URIPath
URIPath("gs://ml/models/latest")               # a GSURIPath
URIPath("az://mycompany/ops/logs/app.log")     # an AZURIPath

uripath finds the classes through the entry points of the group uripath.schemes that this distribution declares; nothing else is needed, and import objpath never imports uripath. Each class is a URI path (see the uripath documentation for everything about URIs) whose requests are done by the matching path of this package, so the two behave alike.

Scheme	Class	Authority	First segment
s3:	S3URIPath	the bucket	the key
gs:	GSURIPath	the bucket	the key
az:	AZURIPath	the storage account	the container, then the key

backend= is a BaseS3Backend, BaseGSBackend or BaseAZBackend used as it is by the path it is given to, whatever bucket the URI names, and by the paths derived from it on the same bucket. Without it, the default backend of the process (of the account, for az:) is used. az://account is a directory whose children are the containers.

Two URI paths of one store reached by one client copy server side, also between buckets (az: within a container); rename() stays within a bucket, and across buckets raises NotImplementedError so move() copies. The callbacks of rm() and copy() get URI paths.