change CohereHook.get_conn type to method (#50470)

Author: sjyangkevin

providers/cohere/src/airflow/providers/cohere/hooks/cohere.py

@@ -19,7 +19,6 @@
 
 import logging
 import warnings
-from functools import cached_property
 from typing import TYPE_CHECKING, Any
 
 import cohere
@@ -65,6 +64,7 @@ def __init__(
         self.timeout = timeout
         self.max_retries = max_retries
         self.request_options = request_options
+        self._client: cohere.ClientV2 | None = None
 
         if self.max_retries:
             warnings.warn(
@@ -77,20 +77,23 @@ def __init__(
             else:
                 self.request_options.update({"max_retries": self.max_retries})
 
-    @cached_property
-    def get_conn(self) -> cohere.ClientV2:  # type: ignore[override]
-        conn = self.get_connection(self.conn_id)
-        return cohere.ClientV2(
-            api_key=conn.password,
-            timeout=self.timeout,
-            base_url=conn.host or None,
-        )
+    def get_conn(self) -> cohere.ClientV2:
+        """Return a new or cached Cohere client instance."""
+        if self._client is None:
+            # create a new client instance if there is no existing client
+            conn = self.get_connection(self.conn_id)
+            self._client = cohere.ClientV2(
+                api_key=conn.password,
+                timeout=self.timeout,
+                base_url=conn.host or None,
+            )
+        return self._client
 
     def create_embeddings(
         self, texts: list[str], model: str = "embed-multilingual-v3.0"
     ) -> EmbedByTypeResponseEmbeddings:
         logger.info("Creating embeddings with model: embed-multilingual-v3.0")
-        response = self.get_conn.embed(
+        response = self.get_conn().embed(
             texts=texts,
             model=model,
             input_type="search_document",
@@ -117,7 +120,7 @@ def test_connection(
         try:
             if messages is None:
                 messages = [UserChatMessageV2(role="user", content="hello world!")]
-            self.get_conn.chat(model=model, messages=messages)
+            self.get_conn().chat(model=model, messages=messages)
             return True, "Connection successfully established."
         except Exception as e:
             return False, f"Unexpected error: {str(e)}"

providers/cohere/tests/unit/cohere/hooks/test_cohere.py

@@ -42,5 +42,5 @@ def test__get_api_key(self):
             patch("cohere.ClientV2") as client,
         ):
             hook = CohereHook(timeout=timeout)
-            _ = hook.get_conn
+            _ = hook.get_conn()
             client.assert_called_once_with(api_key=api_key, timeout=timeout, base_url=base_url)