refactor: remove pre-8.3 XML namespace fallback (#1046)

The `Namespace` class detected `http://tableausoftware.com/api` (the pre-8.3
namespace) at runtime on every XML response and let the parser silently switch
namespaces if it saw the old one. That behavior has been unreachable for years:
the library's `minimum_supported_server_version` is 2.3, which corresponds to
Tableau Server 10.0 -- shipped in 2016, three years after the namespace changed.
Every server TSC has ever admitted uses `http://tableau.com/api`.

Removes:
- `tableauserverclient/namespace.py` (the module) and everything it exported:
  `Namespace`, `UnknownNamespaceError`, `OLD_NAMESPACE`, `NEW_NAMESPACE`,
  `NAMESPACE_RE`.
- `Server._namespace` instance and the per-response `.detect(...)` call in
  `Endpoint._make_request` and both sign-in paths in `Auth`.

Keeps:
- The public `TSC.DEFAULT_NAMESPACE` re-export -- now sourced from
  `tableauserverclient.server.server.NAMESPACE`, which is the canonical
  constant. Same string value.
- `Server.namespace` property -- still returns the `{"t": NAMESPACE}` dict
  callers pass to ElementTree's `namespaces=` kwarg. Same shape.

Callers who imported directly from `tableauserverclient.namespace` (rather
than `TSC.DEFAULT_NAMESPACE`) will break; the CHANGELOG entry calls this out.

Fixes #1046.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: jacalata

CHANGELOG.md

@@ -12,6 +12,13 @@
   `type` / `value` / `text`. The existing `notes: list[str]` attribute is
   unchanged (it parses the separate legacy `<notes>` element still emitted by
   some job types). Fixes #1850.
+* Removed the pre-Tableau-8.3 XML namespace fallback
+  (`http://tableausoftware.com/api`). Every server TSC's `minimum_supported_server_version`
+  guard has ever admitted uses the current namespace (`http://tableau.com/api`),
+  and the runtime-detection code has been unreachable in practice for a
+  decade. `tableauserverclient.namespace` module and `UnknownNamespaceError`
+  are removed; the public `TSC.DEFAULT_NAMESPACE` re-export still works and
+  now points at `tableauserverclient.server.server.NAMESPACE`. Fixes #1046.
 
 ## 0.18.0 (6 April 2022)    
 * Switched to using defused_xml for xml attack protection

tableauserverclient/__init__.py

@@ -1,5 +1,5 @@
 from tableauserverclient.bin._version import get_versions
-from tableauserverclient.namespace import NEW_NAMESPACE as DEFAULT_NAMESPACE
+from tableauserverclient.server.server import NAMESPACE as DEFAULT_NAMESPACE
 from tableauserverclient.models import (
     BackgroundJobItem,
     CollectionItem,

tableauserverclient/namespace.py

@@ -80,7 +80,6 @@ def sign_in(self, auth_req: "Credentials") -> contextmgr:
                 **self.parent_srv.http_options,
                 allow_redirects=False,
             )
-        self.parent_srv._namespace.detect(server_response.content)
         self._check_status(server_response, url)
         parsed_response = fromstring(server_response.content)
         site_id = parsed_response.find(".//t:site", namespaces=self.parent_srv.namespace).get("id", None)
@@ -154,7 +153,6 @@ def switch_site(self, site_item: "SiteItem") -> contextmgr:
                 return Auth.contextmgr(self.sign_out)
             else:
                 raise e
-        self.parent_srv._namespace.detect(server_response.content)
         self._check_status(server_response, url)
         parsed_response = fromstring(server_response.content)
         site_id = parsed_response.find(".//t:site", namespaces=self.parent_srv.namespace).get("id", None)

tableauserverclient/server/endpoint/auth_endpoint.py

@@ -152,9 +152,6 @@ def _make_request(
         # BE CAREFUL WHEN SHARING THESE RESULTS - MAY CONTAIN YOUR SENSITIVE DATA
         # logger.debug(loggable_response)
 
-        if content_type == "application/xml":
-            self.parent_srv._namespace.detect(server_response.content)
-
         return server_response
 
     def _check_status(self, server_response: "Response", url: str | None = None):

tableauserverclient/server/endpoint/endpoint.py

@@ -46,7 +46,6 @@
     EndpointUnavailableError,
 )
 from tableauserverclient.server.endpoint.exceptions import NotSignedInError
-from tableauserverclient.namespace import Namespace
 
 _PRODUCT_TO_REST_VERSION = {
     "10.0": "2.3",
@@ -59,6 +58,11 @@
 minimum_supported_server_version = "2.3"
 default_server_version = "2.4"  # first version that dropped the legacy auth endpoint
 
+# The REST API has used the "http://tableau.com/api" XML namespace since Tableau
+# Server 8.3 (2015). Callers on older servers are unsupported.
+NAMESPACE = "http://tableau.com/api"
+_NAMESPACE_MAP = {"t": NAMESPACE}
+
 
 class Server:
     """
@@ -176,7 +180,6 @@ def __init__(self, server_address, use_server_version=False, http_options=None,
         self.data_acceleration_report = DataAccelerationReport(self)
         self.data_alerts = DataAlerts(self)
         self.fileuploads = Fileuploads(self)
-        self._namespace = Namespace()
         self.flow_runs = FlowRuns(self)
         self.metrics = Metrics(self)
         self.custom_views = CustomViews(self)
@@ -290,7 +293,7 @@ def baseurl(self):
 
     @property
     def namespace(self):
-        return self._namespace()
+        return _NAMESPACE_MAP
 
     @property
     def auth_token(self):