fix(pkg-py): don't import pydantic unless it's relevant/needed

Author: cpsievert

pkg-py/src/shinychat/_chat.py

@@ -46,7 +46,6 @@
     set_chatlas_state,
 )
 from ._chat_normalize import message_content, message_content_chunk
-from ._chat_normalize_chatlas import hide_corresponding_request, is_tool_result
 from ._chat_provider_types import (
     AnthropicMessage,  # pyright: ignore[reportAttributeAccessIssue]
     GoogleMessage,
@@ -69,6 +68,7 @@
     TransformedMessage,
 )
 from ._html_deps_py_shiny import chat_deps
+from ._typing_extensions import TypeGuard
 
 if TYPE_CHECKING:
     import chatlas
@@ -1838,4 +1838,34 @@ async def append(self, message_chunk: Any):
         )
 
 
+async def hide_corresponding_request(x: "chatlas.ContentToolResult"):
+    if x.request is None:
+        return
+
+    session = None
+    try:
+        from shiny.session import get_current_session
+
+        session = get_current_session()
+    except Exception:
+        return
+
+    if session is None:
+        return
+
+    await session.send_custom_message(
+        "shiny-tool-request-hide",
+        x.request.id,  # type: ignore
+    )
+
+
+def is_tool_result(val: object) -> "TypeGuard[chatlas.ContentToolResult]":
+    try:
+        from chatlas.types import ContentToolResult
+
+        return isinstance(val, ContentToolResult)
+    except ImportError:
+        return False
+
+
 CHAT_INSTANCES: WeakValueDictionary[str, Chat] = WeakValueDictionary()

pkg-py/src/shinychat/_chat_normalize_chatlas.py

@@ -18,8 +18,6 @@
 from pydantic import BaseModel, field_serializer, field_validator
 from typing_extensions import TypeAliasType
 
-from ._typing_extensions import TypeGuard
-
 if TYPE_CHECKING:
     from chatlas.types import ContentToolRequest, ContentToolResult
 
@@ -365,36 +363,6 @@ def tool_result_display(
     return str(x.get_model_value()), "code"
 
 
-async def hide_corresponding_request(x: "ContentToolResult"):
-    if x.request is None:
-        return
-
-    session = None
-    try:
-        from shiny.session import get_current_session
-
-        session = get_current_session()
-    except Exception:
-        return
-
-    if session is None:
-        return
-
-    await session.send_custom_message(
-        "shiny-tool-request-hide",
-        x.request.id,  # type: ignore
-    )
-
-
-def is_tool_result(val: object) -> "TypeGuard[ContentToolResult]":
-    try:
-        from chatlas.types import ContentToolResult
-
-        return isinstance(val, ContentToolResult)
-    except ImportError:
-        return False
-
-
 # Tools started getting added to ContentToolRequest staring with 0.11.1
 def is_legacy():
     import chatlas