Revert "fix: de-complicate earlier connection open logic"

This reverts commit d6b1b19.

Signed-off-by: varun-edachali-dbx <varun.edachali@databricks.com>

Author: varun-edachali-dbx

src/databricks/sql/client.py

@@ -343,7 +343,9 @@ def get_protocol_version(openSessionResp):
     @property
     def open(self) -> bool:
         """Return whether the connection is open by checking if the session is open."""
-        return self.session.is_open
+        # NOTE: we have to check for the existence of session in case the __del__ is called
+        # before the session is instantiated
+        return hasattr(self, "session") and self.session.open
 
     def cursor(
         self,

src/databricks/sql/session.py

@@ -31,7 +31,7 @@ def __init__(
 
         This class handles all session-related behavior and communication with the backend.
         """
-        self.is_open = False
+        self.open = False
         self.host = server_hostname
         self.port = kwargs.get("_port", 443)
 
@@ -151,4 +151,4 @@ def close(self) -> None:
         except Exception as e:
             logger.error(f"Attempt to close session raised a local exception: {e}")
 
-        self.is_open = False
+        self.open = False