community[patch]: Improve import callbacks to make it IDE friendly (#20050)

* declares __all__ as a list of strings (instead of dynamically
computing it)
* import type definitions when TYPE_CHECKING is true

libs/community/langchain_community/callbacks/__init__.py

@@ -7,7 +7,78 @@
     BaseCallbackHandler --> <name>CallbackHandler  # Example: AimCallbackHandler
 """
 import importlib
-from typing import Any
+from typing import TYPE_CHECKING, Any
+
+if TYPE_CHECKING:
+    from langchain_community.callbacks.aim_callback import (
+        AimCallbackHandler,  # noqa: F401
+    )
+    from langchain_community.callbacks.argilla_callback import (
+        ArgillaCallbackHandler,  # noqa: F401
+    )
+    from langchain_community.callbacks.arize_callback import (
+        ArizeCallbackHandler,  # noqa: F401
+    )
+    from langchain_community.callbacks.arthur_callback import (
+        ArthurCallbackHandler,  # noqa: F401
+    )
+    from langchain_community.callbacks.clearml_callback import (
+        ClearMLCallbackHandler,  # noqa: F401
+    )
+    from langchain_community.callbacks.comet_ml_callback import (
+        CometCallbackHandler,  # noqa: F401
+    )
+    from langchain_community.callbacks.context_callback import (
+        ContextCallbackHandler,  # noqa: F401
+    )
+    from langchain_community.callbacks.fiddler_callback import (
+        FiddlerCallbackHandler,  # noqa: F401
+    )
+    from langchain_community.callbacks.flyte_callback import (
+        FlyteCallbackHandler,  # noqa: F401
+    )
+    from langchain_community.callbacks.human import (
+        HumanApprovalCallbackHandler,  # noqa: F401
+    )
+    from langchain_community.callbacks.infino_callback import (
+        InfinoCallbackHandler,  # noqa: F401
+    )
+    from langchain_community.callbacks.labelstudio_callback import (
+        LabelStudioCallbackHandler,  # noqa: F401
+    )
+    from langchain_community.callbacks.llmonitor_callback import (
+        LLMonitorCallbackHandler,  # noqa: F401
+    )
+    from langchain_community.callbacks.manager import (  # noqa: F401
+        get_openai_callback,
+        wandb_tracing_enabled,
+    )
+    from langchain_community.callbacks.mlflow_callback import (
+        MlflowCallbackHandler,  # noqa: F401
+    )
+    from langchain_community.callbacks.openai_info import (
+        OpenAICallbackHandler,  # noqa: F401
+    )
+    from langchain_community.callbacks.promptlayer_callback import (
+        PromptLayerCallbackHandler,  # noqa: F401
+    )
+    from langchain_community.callbacks.sagemaker_callback import (
+        SageMakerCallbackHandler,  # noqa: F401
+    )
+    from langchain_community.callbacks.streamlit import (  # noqa: F401
+        LLMThoughtLabeler,
+        StreamlitCallbackHandler,
+    )
+    from langchain_community.callbacks.trubrics_callback import (
+        TrubricsCallbackHandler,  # noqa: F401
+    )
+    from langchain_community.callbacks.wandb_callback import (
+        WandbCallbackHandler,  # noqa: F401
+    )
+    from langchain_community.callbacks.whylabs_callback import (
+        WhyLabsCallbackHandler,  # noqa: F401
+    )
+
 
 _module_lookup = {
     "AimCallbackHandler": "langchain_community.callbacks.aim_callback",
@@ -44,4 +115,29 @@ def __getattr__(name: str) -> Any:
     raise AttributeError(f"module {__name__} has no attribute {name}")
 
 
-__all__ = list(_module_lookup.keys())
+__all__ = [
+    "AimCallbackHandler",
+    "ArgillaCallbackHandler",
+    "ArizeCallbackHandler",
+    "ArthurCallbackHandler",
+    "ClearMLCallbackHandler",
+    "CometCallbackHandler",
+    "ContextCallbackHandler",
+    "FiddlerCallbackHandler",
+    "FlyteCallbackHandler",
+    "HumanApprovalCallbackHandler",
+    "InfinoCallbackHandler",
+    "LLMThoughtLabeler",
+    "LLMonitorCallbackHandler",
+    "LabelStudioCallbackHandler",
+    "MlflowCallbackHandler",
+    "OpenAICallbackHandler",
+    "PromptLayerCallbackHandler",
+    "SageMakerCallbackHandler",
+    "StreamlitCallbackHandler",
+    "TrubricsCallbackHandler",
+    "WandbCallbackHandler",
+    "WhyLabsCallbackHandler",
+    "get_openai_callback",
+    "wandb_tracing_enabled",
+]

libs/community/tests/unit_tests/callbacks/test_imports.py

@@ -1,4 +1,4 @@
-from langchain_community.callbacks import __all__
+from langchain_community.callbacks import __all__, _module_lookup
 
 EXPECTED_ALL = [
     "AimCallbackHandler",
@@ -29,4 +29,6 @@ EXPECTED_ALL = [
 
 
 def test_all_imports() -> None:
+    """Test that __all__ is correctly set."""
     assert set(__all__) == set(EXPECTED_ALL)
+    assert set(__all__) == set(_module_lookup.keys())