fix: correct spelling mistakes of "seperate, intialise, pre-defined" (#14647)

fix spellings

**seperate -> separate**: found more occurrences, see
https://github.com/langchain-ai/langchain/pull/14602
**initialise -> intialize**: the latter is more common in the repo
**pre-defined > predefined**: adding a comma after a prefix is a
delicate matter, but this is a generally accepted word

also, another word that appears in the repo is "fs" (stands for
filesystem), e.g., in `libs/core/langchain_core/prompts/loading.py`
` """Unified method for loading a prompt from LangChainHub or local
fs."""`
Isn't "filesystem" better?

libs/langchain/langchain/agents/agent_iterator.py

@@ -210,7 +210,7 @@ class AgentExecutorIterator:
 
     async def __aiter__(self) -> AsyncIterator[AddableDict]:
         """
-        N.B. __aiter__ must be a normal method, so need to initialise async run manager
+        N.B. __aiter__ must be a normal method, so need to initialize async run manager
         on first __anext__ call where we can await it
         """
         logger.debug("Initialising AgentExecutorIterator (async)")

libs/langchain/langchain/chains/api/news_docs.py

@@ -10,7 +10,7 @@ Request parameters
 
     country | The 2-letter ISO 3166-1 code of the country you want to get headlines for. Possible options: ae ar at au be bg br ca ch cn co cu cz de eg fr gb gr hk hu id ie il in it jp kr lt lv ma mx my ng nl no nz ph pl pt ro rs ru sa se sg si sk th tr tw ua us ve za. Note: you can't mix this param with the sources param.
     category | The category you want to get headlines for. Possible options: business entertainment general health science sports technology. Note: you can't mix this param with the sources param.
-    sources | A comma-seperated string of identifiers for the news sources or blogs you want headlines from. Use the /top-headlines/sources endpoint to locate these programmatically or look at the sources index. Note: you can't mix this param with the country or category params.
+    sources | A comma-separated string of identifiers for the news sources or blogs you want headlines from. Use the /top-headlines/sources endpoint to locate these programmatically or look at the sources index. Note: you can't mix this param with the country or category params.
     q | Keywords or a phrase to search for.
     pageSize | int | The number of results to return per page (request). 20 is the default, 100 is the maximum.
     page | int | Use this to page through the results if the total results found is greater than the page size.

libs/langchain/langchain/evaluation/criteria/__init__.py

@@ -11,7 +11,7 @@ chain against specified criteria.
 
 Examples
 --------
-Using a pre-defined criterion:
+Using a predefined criterion:
 >>> from langchain.llms import OpenAI
 >>> from langchain.evaluation.criteria import CriteriaEvalChain
 

libs/langchain/langchain/output_parsers/format_instructions.py

@@ -50,7 +50,7 @@ Make sure to always enclose the YAML output in triple backticks (```)"""
 
 PANDAS_DATAFRAME_FORMAT_INSTRUCTIONS = """The output should be formatted as a string as the operation, followed by a colon, followed by the column or row to be queried on, followed by optional array parameters.
 1. The column names are limited to the possible columns below.
-2. Arrays must either be a comma-seperated list of numbers formatted as [1,3,5], or it must be in range of numbers formatted as [0..4].
+2. Arrays must either be a comma-separated list of numbers formatted as [1,3,5], or it must be in range of numbers formatted as [0..4].
 3. Remember that arrays are optional and not necessarily required.
 4. If the column is not in the possible columns or the operation is not a valid Pandas DataFrame operation, return why it is invalid as a sentence starting with either "Invalid column" or "Invalid operation".
 

libs/langchain/tests/unit_tests/agents/test_agent_iterator.py

@@ -361,7 +361,7 @@ def test_agent_iterator_failing_tool() -> None:
 
     agent_iter = agent.iter(inputs="when was langchain made")
     assert isinstance(agent_iter, AgentExecutorIterator)
-    # initialise iterator
+    # initialize iterator
     iterator = iter(agent_iter)
 
     with pytest.raises(ZeroDivisionError):