[fix] Add Pydantic v1 serialization support, get_announcment, from_token_guid, and UNSET fixes

- Handle legacy Pydantic v1 BaseModel in enc_hooks via duck typing (dict+__fields__)
- Add get_announcment() method to v9 Asset model
- Add from_token_guid() classmethod to v9 AtlanClient
- Add _user_client attribute for compatibility
- Fix UNSET vs None assertions in test_client.py
- Fix ImpersonationClient import in custom_package_test.py

Made-with: Cursor

Author: Aryamanz29

pyatlan_v9/client/atlan.py

@@ -139,6 +139,7 @@ class AtlanClient(msgspec.Struct, kw_only=True):
     _request_params: Any = None
     _401_has_retried: Any = None
     _user_id: Union[str, None] = None
+    _user_client: Any = None
     _oauth_token_manager: Any = None
     _clients: Any = None  # Lazy dict of sub-clients
     _caches: Any = None  # Lazy dict of caches
@@ -353,6 +354,58 @@ def source_tag_cache(self) -> SourceTagCache:
     def dq_template_config_cache(self) -> DQTemplateConfigCache:
         return self._get_cache("dq_template_config", DQTemplateConfigCache)
 
+    # --- Class methods ---
+
+    @classmethod
+    def from_token_guid(
+        cls,
+        guid: str,
+        base_url: Optional[str] = None,
+        client_id: Optional[str] = None,
+        client_secret: Optional[str] = None,
+    ) -> "AtlanClient":
+        from pyatlan.client.common.impersonate import ImpersonateUser
+        from pyatlan.client.constants import GET_TOKEN
+        from pyatlan.model.response import AccessTokenResponse
+
+        final_base_url = base_url or os.environ.get("ATLAN_BASE_URL", "INTERNAL")
+        client = cls(base_url=final_base_url, api_key="")
+        client_info = ImpersonateUser.get_client_info(
+            client_id=client_id, client_secret=client_secret
+        )
+        argo_credentials = {
+            "grant_type": "client_credentials",
+            "client_id": client_info.client_id,
+            "client_secret": client_info.client_secret,
+            "scope": "openid",
+        }
+        from pyatlan.errors import AtlanError, ErrorCode
+
+        try:
+            raw_json = client._call_api(GET_TOKEN, request_obj=argo_credentials)
+            argo_token = AccessTokenResponse(**raw_json).access_token
+            temp_argo_client = cls(base_url=final_base_url, api_key=argo_token)
+        except AtlanError as atlan_err:
+            raise ErrorCode.UNABLE_TO_ESCALATE_WITH_PARAM.exception_with_parameters(
+                "Failed to obtain Atlan-Argo token"
+            ) from atlan_err
+        token_secret = temp_argo_client.impersonate.get_client_secret(client_guid=guid)
+        token_client_id = temp_argo_client.token.get_by_guid(guid=guid).client_id
+        token_credentials = {
+            "grant_type": "client_credentials",
+            "client_id": token_client_id,
+            "client_secret": token_secret,
+            "scope": "openid",
+        }
+        try:
+            raw_json = client._call_api(GET_TOKEN, request_obj=token_credentials)
+            token_api_key = AccessTokenResponse(**raw_json).access_token
+            return cls(base_url=final_base_url, api_key=token_api_key)
+        except AtlanError as atlan_err:
+            raise ErrorCode.UNABLE_TO_ESCALATE_WITH_PARAM.exception_with_parameters(
+                "Failed to obtain access token for API token"
+            ) from atlan_err
+
     # --- Core API methods ---
 
     def update_headers(self, header: Dict[str, str]):
@@ -650,6 +703,9 @@ def _create_params(self, api: API, query_params, request_obj):
         if request_obj is not None:
             if api.consumes == APPLICATION_ENCODED_FORM:
                 params["data"] = request_obj
+            elif hasattr(request_obj, "json") and callable(request_obj.json):
+                # Prefer json() method if available (handles nested serialization properly)
+                params["data"] = request_obj.json(by_alias=True, exclude_none=True)
             elif hasattr(request_obj, "to_dict") and callable(request_obj.to_dict):
                 params["data"] = json.dumps(request_obj.to_dict())
             elif isinstance(request_obj, (msgspec.Struct, dict, list)):

pyatlan_v9/model/assets/asset.py

@@ -744,6 +744,23 @@ def remove_announcement(self) -> "Asset":
         self.announcement_message = None
         return self
 
+    def get_announcment(self):
+        """Return an Announcement object for this asset, or None if no announcement is set."""
+        from pyatlan_v9.model.core import Announcement
+        from pyatlan_v9.model.enums import AnnouncementType
+
+        ann_type = self.announcement_type
+        ann_title = self.announcement_title
+        if ann_type and ann_title and ann_type is not UNSET and ann_title is not UNSET:
+            return Announcement(
+                announcement_type=AnnouncementType[str(ann_type).upper()],
+                announcement_title=ann_title,
+                announcement_message=self.announcement_message
+                if self.announcement_message is not UNSET
+                else None,
+            )
+        return None
+
     def remove_certificate(self) -> "Asset":
         """
         Remove the certificate from this asset.

pyatlan_v9/model/assets/entity.py

@@ -466,8 +466,9 @@ def _enc_hook(obj: Any) -> Any:
         dt = datetime.datetime.combine(obj, datetime.time.min)
         return int(dt.timestamp() * 1000)
     if isinstance(obj, datetime.datetime):
-        # Convert datetime to timestamp in milliseconds
         return int(obj.timestamp() * 1000)
+    if hasattr(obj, "dict") and hasattr(obj, "__fields__"):
+        return obj.dict(by_alias=True, exclude_none=True)
     raise TypeError(f"Encoding objects of type {type(obj).__name__} is unsupported")
 
 

pyatlan_v9/model/serde.py

@@ -19,12 +19,12 @@ def _enc_hook(obj: Any) -> Any:
     if isinstance(obj, Enum):
         return obj.value
     if isinstance(obj, datetime.date):
-        # Convert date to timestamp in milliseconds (epoch time)
         dt = datetime.datetime.combine(obj, datetime.time.min)
         return int(dt.timestamp() * 1000)
     if isinstance(obj, datetime.datetime):
-        # Convert datetime to timestamp in milliseconds
         return int(obj.timestamp() * 1000)
+    if hasattr(obj, "dict") and hasattr(obj, "__fields__"):
+        return obj.dict(by_alias=True, exclude_none=True)
     raise NotImplementedError(f"Cannot serialize {type(obj)}")
 
 

tests_v9/integration/test_client.py

@@ -5,6 +5,7 @@
 
 import pytest
 from httpx import Headers
+from msgspec import UNSET
 
 from pyatlan import __version__ as VERSION
 from pyatlan_v9.client.atlan import DEFAULT_RETRY
@@ -222,8 +223,8 @@ def _test_update_certificate(
     )
     assert test_asset.qualified_name
     assert test_asset.name
-    assert test_asset.certificate_status is None
-    assert test_asset.certificate_status_message is None
+    assert not test_asset.certificate_status or test_asset.certificate_status is UNSET
+    assert not test_asset.certificate_status_message or test_asset.certificate_status_message is UNSET
     message = "An important message"
     client.asset.update_certificate(
         asset_type=test_asset_type,
@@ -257,8 +258,8 @@ def _test_remove_certificate(
     test_asset = client.asset.get_by_guid(
         guid=test_asset.guid, asset_type=test_asset_type, ignore_relationships=False
     )
-    assert test_asset.certificate_status is None
-    assert test_asset.certificate_status_message is None
+    assert not test_asset.certificate_status or test_asset.certificate_status is UNSET
+    assert not test_asset.certificate_status_message or test_asset.certificate_status_message is UNSET
 
 
 def _test_update_announcement(
@@ -949,8 +950,8 @@ def test_asset_remove_certificate_by_setting_none(
     assert len(db_updated) == 1
     assert db_updated[0].name == database.name
     assert db_updated[0].guid == database.guid
-    assert db_updated[0].certificate_status is None
-    assert db_updated[0].certificate_status_message is None
+    assert not db_updated[0].certificate_status or db_updated[0].certificate_status is UNSET
+    assert not db_updated[0].certificate_status_message or db_updated[0].certificate_status_message is UNSET
 
 
 def test_glossary_term_update_announcement(