Supported OutputFixingParser max_retries (#11754)

Description: Supported OutputFixingParser max_retries
 - max_retries: Maximum number of retries to parser.

Issue: None
Dependencies: None
Tag maintainer: @baskaryan
Twitter handle: @JohnMai95

---------

Co-authored-by: Bagatur <baskaryan@gmail.com>

libs/langchain/langchain/output_parsers/fix.py

@@ -19,6 +19,7 @@ class OutputFixingParser(BaseOutputParser[T]):
     parser: BaseOutputParser[T]
     # Should be an LLMChain but we want to avoid top-level imports from langchain.chains
     retry_chain: Any
+    max_retries: int = 1
 
     @classmethod
     def from_llm(
@@ -26,6 +27,7 @@ class OutputFixingParser(BaseOutputParser[T]):
         llm: BaseLanguageModel,
         parser: BaseOutputParser[T],
         prompt: BasePromptTemplate = NAIVE_FIX_PROMPT,
+        max_retries: int = 1,
     ) -> OutputFixingParser[T]:
         """Create an OutputFixingParser from a language model and a parser.
 
@@ -33,6 +35,7 @@ class OutputFixingParser(BaseOutputParser[T]):
             llm: llm to use for fixing
             parser: parser to use for parsing
             prompt: prompt to use for fixing
+            max_retries: Maximum number of retries to parser.
 
         Returns:
             OutputFixingParser
@@ -40,33 +43,45 @@ class OutputFixingParser(BaseOutputParser[T]):
         from langchain.chains.llm import LLMChain
 
         chain = LLMChain(llm=llm, prompt=prompt)
-        return cls(parser=parser, retry_chain=chain)
+        return cls(parser=parser, retry_chain=chain, max_retries=max_retries)
 
     def parse(self, completion: str) -> T:
-        try:
-            parsed_completion = self.parser.parse(completion)
-        except OutputParserException as e:
-            new_completion = self.retry_chain.run(
-                instructions=self.parser.get_format_instructions(),
-                completion=completion,
-                error=repr(e),
-            )
-            parsed_completion = self.parser.parse(new_completion)
-
-        return parsed_completion
+        retries = 0
+
+        while retries <= self.max_retries:
+            try:
+                return self.parser.parse(completion)
+            except OutputParserException as e:
+                if retries == self.max_retries:
+                    raise e
+                else:
+                    retries += 1
+                    completion = self.retry_chain.run(
+                        instructions=self.parser.get_format_instructions(),
+                        completion=completion,
+                        error=repr(e),
+                    )
+
+        raise OutputParserException("Failed to parse")
 
     async def aparse(self, completion: str) -> T:
-        try:
-            parsed_completion = self.parser.parse(completion)
-        except OutputParserException as e:
-            new_completion = await self.retry_chain.arun(
-                instructions=self.parser.get_format_instructions(),
-                completion=completion,
-                error=repr(e),
-            )
-            parsed_completion = self.parser.parse(new_completion)
-
-        return parsed_completion
+        retries = 0
+
+        while retries <= self.max_retries:
+            try:
+                return await self.parser.aparse(completion)
+            except OutputParserException as e:
+                if retries == self.max_retries:
+                    raise e
+                else:
+                    retries += 1
+                    completion = await self.retry_chain.arun(
+                        instructions=self.parser.get_format_instructions(),
+                        completion=completion,
+                        error=repr(e),
+                    )
+
+        raise OutputParserException("Failed to parse")
 
     def get_format_instructions(self) -> str:
         return self.parser.get_format_instructions()