fix: formatting issues in docstrings (#32265)

Ensures proper reStructuredText formatting by adding the required blank
line before closing docstring quotes, which resolves the "Block quote
ends without a blank line; unexpected unindent" warning.

libs/core/langchain_core/prompts/base.py

@@ -307,6 +307,7 @@ class BasePromptTemplate(
         .. code-block:: python
 
             prompt.format(variable1="foo")
+
         """
 
     async def aformat(self, **kwargs: Any) -> FormatOutputType:
@@ -323,6 +324,7 @@ class BasePromptTemplate(
         .. code-block:: python
 
             await prompt.aformat(variable1="foo")
+
         """
         return self.format(**kwargs)
 
@@ -363,6 +365,7 @@ class BasePromptTemplate(
         .. code-block:: python
 
             prompt.save(file_path="path/prompt.yaml")
+
         """
         if self.partial_variables:
             msg = "Cannot save prompt with partial variables."
@@ -442,6 +445,7 @@ def format_document(doc: Document, prompt: BasePromptTemplate[str]) -> str:
             prompt = PromptTemplate.from_template("Page {page}: {page_content}")
             format_document(doc, prompt)
             >>> "Page 1: This is a joke"
+
     """
     return prompt.format(**_get_document_info(doc, prompt))
 

libs/core/langchain_core/prompts/chat.py

@@ -126,6 +126,7 @@ class MessagesPlaceholder(BaseMessagePromptTemplate):
             # -> [
             #     HumanMessage(content="Hello!"),
             # ]
+
     """
 
     variable_name: str
@@ -1164,6 +1165,7 @@ class ChatPromptTemplate(BaseChatPromptTemplate):
 
         Returns:
             a chat prompt template.
+
         """
         return cls(messages, template_format=template_format)
 
@@ -1248,6 +1250,7 @@ class ChatPromptTemplate(BaseChatPromptTemplate):
                 template2 = template.partial(user="Lucy", name="R2D2")
 
                 template2.format_messages(input="hello")
+
         """
         prompt_dict = self.__dict__.copy()
         prompt_dict["input_variables"] = list(

libs/core/langchain_core/prompts/few_shot.py

@@ -357,6 +357,7 @@ class FewShotChatMessagePromptTemplate(
             from langchain_core.chat_models import ChatAnthropic
             chain = final_prompt | ChatAnthropic(model="claude-3-haiku-20240307")
             chain.invoke({"input": "What's 3+3?"})
+
     """
 
     input_variables: list[str] = Field(default_factory=list)

libs/core/langchain_core/prompts/few_shot_with_templates.py

@@ -122,6 +122,7 @@ class FewShotPromptWithTemplates(StringPromptTemplate):
         .. code-block:: python
 
             prompt.format(variable1="foo")
+
         """
         kwargs = self._merge_partial_and_user_variables(**kwargs)
         # Get the examples to use.

libs/core/langchain_core/prompts/image.py

@@ -90,6 +90,7 @@ class ImagePromptTemplate(BasePromptTemplate[ImageURL]):
             .. code-block:: python
 
                 prompt.format(variable1="foo")
+
         """
         formatted = {}
         for k, v in self.template.items():

libs/core/langchain_core/prompts/pipeline.py

@@ -45,6 +45,7 @@ class PipelinePromptTemplate(BasePromptTemplate):
           Each PromptTemplate will be formatted and then passed
           to future prompt templates as a variable with
           the same name as `name`
+
     """
 
     final_prompt: BasePromptTemplate

libs/core/langchain_core/prompts/prompt.py

@@ -56,6 +56,7 @@ class PromptTemplate(StringPromptTemplate):
 
             # Instantiation using initializer
             prompt = PromptTemplate(template="Say {foo}")
+
     """
 
     @property

libs/core/langchain_core/prompts/structured.py

@@ -115,6 +115,7 @@ class StructuredPrompt(ChatPromptTemplate):
 
         Returns:
             a structured prompt template
+
         """
         return cls(messages, schema, **kwargs)