core: Add ruff rules for comprehensions (C4) (#26829)

libs/core/langchain_core/beta/runnables/context.py

@@ -86,9 +86,9 @@ def _config_with_context(
         )
     }
     deps_by_key = {
-        key: set(
+        key: {
             _key_from_id(dep) for spec in group for dep in (spec[0].dependencies or [])
-        )
+        }
         for key, group in grouped_by_key.items()
     }
 
@@ -198,7 +198,7 @@ async def ainvoke(
         configurable = config.get("configurable", {})
         if isinstance(self.key, list):
             values = await asyncio.gather(*(configurable[id_]() for id_ in self.ids))
-            return {key: value for key, value in zip(self.key, values)}
+            return dict(zip(self.key, values))
         else:
             return await configurable[self.ids[0]]()
 

libs/core/langchain_core/language_models/chat_models.py

@@ -551,7 +551,7 @@ def _get_ls_params(
     def _get_llm_string(self, stop: Optional[list[str]] = None, **kwargs: Any) -> str:
         if self.is_lc_serializable():
             params = {**kwargs, **{"stop": stop}}
-            param_string = str(sorted([(k, v) for k, v in params.items()]))
+            param_string = str(sorted(params.items()))
             # This code is not super efficient as it goes back and forth between
             # json and dict.
             serialized_repr = self._serialized
@@ -561,7 +561,7 @@ def _get_llm_string(self, stop: Optional[list[str]] = None, **kwargs: Any) -> st
         else:
             params = self._get_invocation_params(stop=stop, **kwargs)
             params = {**params, **kwargs}
-            return str(sorted([(k, v) for k, v in params.items()]))
+            return str(sorted(params.items()))
 
     def generate(
         self,

libs/core/langchain_core/language_models/llms.py

@@ -166,7 +166,7 @@ def get_prompts(
     Raises:
         ValueError: If the cache is not set and cache is True.
     """
-    llm_string = str(sorted([(k, v) for k, v in params.items()]))
+    llm_string = str(sorted(params.items()))
     missing_prompts = []
     missing_prompt_idxs = []
     existing_prompts = {}
@@ -202,7 +202,7 @@ async def aget_prompts(
     Raises:
         ValueError: If the cache is not set and cache is True.
     """
-    llm_string = str(sorted([(k, v) for k, v in params.items()]))
+    llm_string = str(sorted(params.items()))
     missing_prompts = []
     missing_prompt_idxs = []
     existing_prompts = {}

libs/core/langchain_core/load/load.py

@@ -67,14 +67,14 @@ def __init__(
                 Defaults to None.
         """
         self.secrets_from_env = secrets_from_env
-        self.secrets_map = secrets_map or dict()
+        self.secrets_map = secrets_map or {}
         # By default, only support langchain, but user can pass in additional namespaces
         self.valid_namespaces = (
             [*DEFAULT_NAMESPACES, *valid_namespaces]
             if valid_namespaces
             else DEFAULT_NAMESPACES
         )
-        self.additional_import_mappings = additional_import_mappings or dict()
+        self.additional_import_mappings = additional_import_mappings or {}
         self.import_mappings = (
             {
                 **ALL_SERIALIZABLE_MAPPINGS,
@@ -146,7 +146,7 @@ def __call__(self, value: dict[str, Any]) -> Any:
 
             # We don't need to recurse on kwargs
             # as json.loads will do that for us.
-            kwargs = value.get("kwargs", dict())
+            kwargs = value.get("kwargs", {})
             return cls(**kwargs)
 
         return value

libs/core/langchain_core/load/serializable.py

@@ -138,7 +138,7 @@ def lc_secrets(self) -> dict[str, str]:
         For example,
             {"openai_api_key": "OPENAI_API_KEY"}
         """
-        return dict()
+        return {}
 
     @property
     def lc_attributes(self) -> dict:
@@ -188,7 +188,7 @@ def to_json(self) -> Union[SerializedConstructor, SerializedNotImplemented]:
         if not self.is_lc_serializable():
             return self.to_json_not_implemented()
 
-        secrets = dict()
+        secrets = {}
         # Get latest values for kwargs if there is an attribute with same name
         lc_kwargs = {}
         for k, v in self:

libs/core/langchain_core/output_parsers/json.py

@@ -108,7 +108,7 @@ def get_format_instructions(self) -> str:
             return "Return a JSON object."
         else:
             # Copy schema to avoid altering original Pydantic schema.
-            schema = {k: v for k, v in self._get_schema(self.pydantic_object).items()}
+            schema = dict(self._get_schema(self.pydantic_object).items())
 
             # Remove extraneous fields.
             reduced_schema = schema

libs/core/langchain_core/output_parsers/pydantic.py

@@ -90,7 +90,7 @@ def get_format_instructions(self) -> str:
             The format instructions for the JSON output.
         """
         # Copy schema to avoid altering original Pydantic schema.
-        schema = {k: v for k, v in self.pydantic_object.model_json_schema().items()}
+        schema = dict(self.pydantic_object.model_json_schema().items())
 
         # Remove extraneous fields.
         reduced_schema = schema

libs/core/langchain_core/outputs/llm_result.py

@@ -76,7 +76,7 @@ def flatten(self) -> list[LLMResult]:
             else:
                 if self.llm_output is not None:
                     llm_output = deepcopy(self.llm_output)
-                    llm_output["token_usage"] = dict()
+                    llm_output["token_usage"] = {}
                 else:
                     llm_output = None
                 llm_results.append(

libs/core/langchain_core/prompts/chat.py

@@ -1007,11 +1007,11 @@ def __init__(
                 input_vars.update(_message.input_variables)
 
         kwargs = {
-            **dict(
-                input_variables=sorted(input_vars),
-                optional_variables=sorted(optional_variables),
-                partial_variables=partial_vars,
-            ),
+            **{
+                "input_variables": sorted(input_vars),
+                "optional_variables": sorted(optional_variables),
+                "partial_variables": partial_vars,
+            },
             **kwargs,
         }
         cast(type[ChatPromptTemplate], super()).__init__(messages=_messages, **kwargs)

libs/core/langchain_core/prompts/image.py

@@ -18,7 +18,7 @@ def __init__(self, **kwargs: Any) -> None:
         if "input_variables" not in kwargs:
             kwargs["input_variables"] = []
 
-        overlap = set(kwargs["input_variables"]) & set(("url", "path", "detail"))
+        overlap = set(kwargs["input_variables"]) & {"url", "path", "detail"}
         if overlap:
             raise ValueError(
                 "input_variables for the image template cannot contain"

libs/core/langchain_core/prompts/prompt.py

@@ -144,7 +144,7 @@ def __add__(self, other: Any) -> PromptTemplate:
             template = self.template + other.template
             # If any do not want to validate, then don't
             validate_template = self.validate_template and other.validate_template
-            partial_variables = {k: v for k, v in self.partial_variables.items()}
+            partial_variables = dict(self.partial_variables.items())
             for k, v in other.partial_variables.items():
                 if k in partial_variables:
                     raise ValueError("Cannot have same variable partialed twice.")

libs/core/langchain_core/runnables/base.py

@@ -3778,7 +3778,7 @@ async def _ainvoke_step(
                     for key, step in steps.items()
                 )
             )
-            output = {key: value for key, value in zip(steps, results)}
+            output = dict(zip(steps, results))
         # finish the root run
         except BaseException as e:
             await run_manager.on_chain_error(e)

libs/core/langchain_core/runnables/fallbacks.py

@@ -294,7 +294,7 @@ def batch(
         ]
 
         to_return: dict[int, Any] = {}
-        run_again = {i: input for i, input in enumerate(inputs)}
+        run_again = dict(enumerate(inputs))
         handled_exceptions: dict[int, BaseException] = {}
         first_to_raise = None
         for runnable in self.runnables:
@@ -388,7 +388,7 @@ async def abatch(
         )
 
         to_return = {}
-        run_again = {i: input for i, input in enumerate(inputs)}
+        run_again = dict(enumerate(inputs))
         handled_exceptions: dict[int, BaseException] = {}
         first_to_raise = None
         for runnable in self.runnables:

libs/core/langchain_core/runnables/retry.py

@@ -117,7 +117,7 @@ def get_lc_namespace(cls) -> list[str]:
 
     @property
     def _kwargs_retrying(self) -> dict[str, Any]:
-        kwargs: dict[str, Any] = dict()
+        kwargs: dict[str, Any] = {}
 
         if self.max_attempt_number:
             kwargs["stop"] = stop_after_attempt(self.max_attempt_number)

libs/core/langchain_core/sys_info.py

@@ -10,7 +10,7 @@ def _get_sub_deps(packages: Sequence[str]) -> list[str]:
     from importlib import metadata
 
     sub_deps = set()
-    _underscored_packages = set(pkg.replace("-", "_") for pkg in packages)
+    _underscored_packages = {pkg.replace("-", "_") for pkg in packages}
 
     for pkg in packages:
         try:
@@ -33,7 +33,7 @@ def _get_sub_deps(packages: Sequence[str]) -> list[str]:
     return sorted(sub_deps, key=lambda x: x.lower())
 
 
-def print_sys_info(*, additional_pkgs: Sequence[str] = tuple()) -> None:
+def print_sys_info(*, additional_pkgs: Sequence[str] = ()) -> None:
     """Print information about the environment for debugging purposes.
 
     Args:

libs/core/langchain_core/tools/base.py

@@ -975,7 +975,7 @@ def _get_all_basemodel_annotations(
             ) and name not in fields:
                 continue
             annotations[name] = param.annotation
-        orig_bases: tuple = getattr(cls, "__orig_bases__", tuple())
+        orig_bases: tuple = getattr(cls, "__orig_bases__", ())
     # cls has subscript: cls = FooBar[int]
     else:
         annotations = _get_all_basemodel_annotations(
@@ -1007,11 +1007,9 @@ def _get_all_basemodel_annotations(
             # parent_origin = Baz,
             # generic_type_vars = (type vars in Baz)
             # generic_map = {type var in Baz: str}
-            generic_type_vars: tuple = getattr(parent_origin, "__parameters__", tuple())
-            generic_map = {
-                type_var: t for type_var, t in zip(generic_type_vars, get_args(parent))
-            }
-            for field in getattr(parent_origin, "__annotations__", dict()):
+            generic_type_vars: tuple = getattr(parent_origin, "__parameters__", ())
+            generic_map = dict(zip(generic_type_vars, get_args(parent)))
+            for field in getattr(parent_origin, "__annotations__", {}):
                 annotations[field] = _replace_type_vars(
                     annotations[field], generic_map, default_to_bound
                 )

libs/core/langchain_core/utils/function_calling.py

@@ -233,9 +233,7 @@ def _convert_any_typed_dicts_to_pydantic(
                 new_arg_type = _convert_any_typed_dicts_to_pydantic(
                     annotated_args[0], depth=depth + 1, visited=visited
                 )
-                field_kwargs = {
-                    k: v for k, v in zip(("default", "description"), annotated_args[1:])
-                }
+                field_kwargs = dict(zip(("default", "description"), annotated_args[1:]))
                 if (field_desc := field_kwargs.get("description")) and not isinstance(
                     field_desc, str
                 ):

libs/core/pyproject.toml

@@ -44,7 +44,7 @@ python = ">=3.12.4"
 [tool.poetry.extras]
 
 [tool.ruff.lint]
-select = [ "B", "E", "F", "I", "N", "T201", "UP",]
+select = [ "B", "C4", "E", "F", "I", "N", "T201", "UP",]
 ignore = [ "UP007",]
 
 [tool.coverage.run]

libs/core/tests/unit_tests/document_loaders/test_langsmith.py

@@ -54,5 +54,5 @@ def test_lazy_load() -> None:
         expected.append(
             Document(example.inputs["first"]["second"].upper(), metadata=metadata)
         )
-    actual = [doc for doc in loader.lazy_load()]
+    actual = list(loader.lazy_load())
     assert expected == actual

libs/core/tests/unit_tests/fake/test_fake_chat_model.py

@@ -55,7 +55,7 @@ async def test_generic_fake_chat_model_stream() -> None:
     ]
     assert len({chunk.id for chunk in chunks}) == 1
 
-    chunks = [chunk for chunk in model.stream("meow")]
+    chunks = list(model.stream("meow"))
     assert chunks == [
         _any_id_ai_message_chunk(content="hello"),
         _any_id_ai_message_chunk(content=" "),

libs/core/tests/unit_tests/indexing/test_indexing.py

@@ -185,11 +185,11 @@ def test_index_simple_delete_full(
     ):
         indexing_result = index(loader, record_manager, vector_store, cleanup="full")
 
-        doc_texts = set(
+        doc_texts = {
             # Ignoring type since doc should be in the store and not a None
             vector_store.get_by_ids([uid])[0].page_content  # type: ignore
             for uid in vector_store.store
-        )
+        }
         assert doc_texts == {"mutated document 1", "This is another document."}
 
         assert indexing_result == {
@@ -267,11 +267,11 @@ async def test_aindex_simple_delete_full(
             "num_updated": 0,
         }
 
-    doc_texts = set(
+    doc_texts = {
         # Ignoring type since doc should be in the store and not a None
         vector_store.get_by_ids([uid])[0].page_content  # type: ignore
         for uid in vector_store.store
-    )
+    }
     assert doc_texts == {"mutated document 1", "This is another document."}
 
     # Attempt to index again verify that nothing changes
@@ -558,11 +558,11 @@ def test_incremental_delete(
             "num_updated": 0,
         }
 
-    doc_texts = set(
+    doc_texts = {
         # Ignoring type since doc should be in the store and not a None
         vector_store.get_by_ids([uid])[0].page_content  # type: ignore
         for uid in vector_store.store
-    )
+    }
     assert doc_texts == {"This is another document.", "This is a test document."}
 
     # Attempt to index again verify that nothing changes
@@ -617,11 +617,11 @@ def test_incremental_delete(
             "num_updated": 0,
         }
 
-    doc_texts = set(
+    doc_texts = {
         # Ignoring type since doc should be in the store and not a None
         vector_store.get_by_ids([uid])[0].page_content  # type: ignore
         for uid in vector_store.store
-    )
+    }
     assert doc_texts == {
         "mutated document 1",
         "mutated document 2",
@@ -685,11 +685,11 @@ def test_incremental_indexing_with_batch_size(
             "num_updated": 0,
         }
 
-    doc_texts = set(
+    doc_texts = {
         # Ignoring type since doc should be in the store and not a None
         vector_store.get_by_ids([uid])[0].page_content  # type: ignore
         for uid in vector_store.store
-    )
+    }
     assert doc_texts == {"1", "2", "3", "4"}
 
 
@@ -735,11 +735,11 @@ def test_incremental_delete_with_batch_size(
             "num_updated": 0,
         }
 
-    doc_texts = set(
+    doc_texts = {
         # Ignoring type since doc should be in the store and not a None
         vector_store.get_by_ids([uid])[0].page_content  # type: ignore
         for uid in vector_store.store
-    )
+    }
     assert doc_texts == {"1", "2", "3", "4"}
 
     # Attempt to index again verify that nothing changes
@@ -880,11 +880,11 @@ async def test_aincremental_delete(
             "num_updated": 0,
         }
 
-    doc_texts = set(
+    doc_texts = {
         # Ignoring type since doc should be in the store and not a None
         vector_store.get_by_ids([uid])[0].page_content  # type: ignore
         for uid in vector_store.store
-    )
+    }
     assert doc_texts == {"This is another document.", "This is a test document."}
 
     # Attempt to index again verify that nothing changes
@@ -939,11 +939,11 @@ async def test_aincremental_delete(
             "num_updated": 0,
         }
 
-    doc_texts = set(
+    doc_texts = {
         # Ignoring type since doc should be in the store and not a None
         vector_store.get_by_ids([uid])[0].page_content  # type: ignore
         for uid in vector_store.store
-    )
+    }
     assert doc_texts == {
         "mutated document 1",
         "mutated document 2",