core: Add ruff rules RUF (#29353)

See https://docs.astral.sh/ruff/rules/#ruff-specific-rules-ruf
Mostly:
* [RUF022](https://docs.astral.sh/ruff/rules/unsorted-dunder-all/)
(unsorted `__all__`)
* [RUF100](https://docs.astral.sh/ruff/rules/unused-noqa/) (unused noqa)
*
[RUF021](https://docs.astral.sh/ruff/rules/parenthesize-chained-operators/)
(parenthesize-chained-operators)
*
[RUF015](https://docs.astral.sh/ruff/rules/unnecessary-iterable-allocation-for-first-element/)
(unnecessary-iterable-allocation-for-first-element)
*
[RUF005](https://docs.astral.sh/ruff/rules/collection-literal-concatenation/)
(collection-literal-concatenation)
* [RUF046](https://docs.astral.sh/ruff/rules/unnecessary-cast-to-int/)
(unnecessary-cast-to-int)

---------

Co-authored-by: Eugene Yurtsev <eyurtsev@gmail.com>

libs/core/langchain_core/prompts/__init__.py

@@ -70,21 +70,21 @@ __all__ = (
     "ChatMessagePromptTemplate",
     "ChatPromptTemplate",
     "DictPromptTemplate",
+    "FewShotChatMessagePromptTemplate",
     "FewShotPromptTemplate",
     "FewShotPromptWithTemplates",
-    "FewShotChatMessagePromptTemplate",
     "HumanMessagePromptTemplate",
     "MessagesPlaceholder",
     "PipelinePromptTemplate",
     "PromptTemplate",
     "StringPromptTemplate",
     "SystemMessagePromptTemplate",
-    "load_prompt",
-    "format_document",
     "aformat_document",
     "check_valid_template",
+    "format_document",
     "get_template_variables",
     "jinja2_formatter",
+    "load_prompt",
     "validate_jinja2",
 )
 

libs/core/langchain_core/prompts/chat.py

@@ -445,9 +445,8 @@ class _StringImageMessagePromptTemplate(BaseMessagePromptTemplate):
                 raise ValueError(msg)
             prompt = []
             for tmpl in template:
-                if (
-                    isinstance(tmpl, str)
-                    or isinstance(tmpl, dict)
+                if isinstance(tmpl, str) or (
+                    isinstance(tmpl, dict)
                     and "text" in tmpl
                     and set(tmpl.keys()) <= {"type", "text"}
                 ):
@@ -524,7 +523,7 @@ class _StringImageMessagePromptTemplate(BaseMessagePromptTemplate):
                     raise ValueError(msg)
             return cls(prompt=prompt, **kwargs)
         msg = f"Invalid template: {template}"
-        raise ValueError(msg)  # noqa: TRY004
+        raise ValueError(msg)
 
     @classmethod
     def from_template_file(
@@ -1000,7 +999,7 @@ class ChatPromptTemplate(BaseChatPromptTemplate):
         if isinstance(
             other, (BaseMessagePromptTemplate, BaseMessage, BaseChatPromptTemplate)
         ):
-            return ChatPromptTemplate(messages=self.messages + [other]).partial(
+            return ChatPromptTemplate(messages=[*self.messages, other]).partial(
                 **partials
             )
         if isinstance(other, (list, tuple)):
@@ -1010,7 +1009,7 @@ class ChatPromptTemplate(BaseChatPromptTemplate):
             )
         if isinstance(other, str):
             prompt = HumanMessagePromptTemplate.from_template(other)
-            return ChatPromptTemplate(messages=self.messages + [prompt]).partial(
+            return ChatPromptTemplate(messages=[*self.messages, prompt]).partial(
                 **partials
             )
         msg = f"Unsupported operand type for +: {type(other)}"

libs/core/langchain_core/prompts/loading.py

@@ -84,15 +84,11 @@ def _load_examples(config: dict) -> dict:
 
 def _load_output_parser(config: dict) -> dict:
     """Load output parser."""
-    if "output_parser" in config and config["output_parser"]:
-        _config = config.pop("output_parser")
-        output_parser_type = _config.pop("_type")
-        if output_parser_type == "default":
-            output_parser = StrOutputParser(**_config)
-        else:
+    if _config := config.get("output_parser"):
+        if output_parser_type := _config.get("_type") != "default":
             msg = f"Unsupported output parser {output_parser_type}"
             raise ValueError(msg)
-        config["output_parser"] = output_parser
+        config["output_parser"] = StrOutputParser(**_config)
     return config
 
 

libs/core/langchain_core/prompts/structured.py

@@ -153,10 +153,8 @@ class StructuredPrompt(ChatPromptTemplate):
             NotImplementedError: If the first element of `others`
             is not a language model.
         """
-        if (
-            others
-            and isinstance(others[0], BaseLanguageModel)
-            or hasattr(others[0], "with_structured_output")
+        if (others and isinstance(others[0], BaseLanguageModel)) or hasattr(
+            others[0], "with_structured_output"
         ):
             return RunnableSequence(
                 self,