Crewating a tool output parser

src/crewai/tools/tool_output_parser.py

@@ -0,0 +1,39 @@
+import json
+from typing import Any, List
+
+import regex
+from langchain.output_parsers import PydanticOutputParser
+from langchain_core.exceptions import OutputParserException
+from langchain_core.outputs import Generation
+from langchain_core.pydantic_v1 import ValidationError
+
+
+class ToolOutputParser(PydanticOutputParser):
+    """Parses the function calling of a tool usage and it's arguments."""
+
+    def parse_result(self, result: List[Generation], *, partial: bool = False) -> Any:
+        result[0].text = self._transform_in_valid_json(result[0].text)
+        json_object = super().parse_result(result)
+        try:
+            return self.pydantic_object.parse_obj(json_object)
+        except ValidationError as e:
+            name = self.pydantic_object.__name__
+            msg = f"Failed to parse {name} from completion {json_object}. Got: {e}"
+            raise OutputParserException(msg, llm_output=json_object)
+
+    def _transform_in_valid_json(self, text) -> str:
+        text = text.replace("```", "").replace("json", "")
+        json_pattern = r"\{(?:[^{}]|(?R))*\}"
+        matches = regex.finditer(json_pattern, text)
+
+        for match in matches:
+            try:
+                # Attempt to parse the matched string as JSON
+                json_obj = json.loads(match.group())
+                # Return the first successfully parsed JSON object
+                json_obj = json.dumps(json_obj)
+                return str(json_obj)
+            except json.JSONDecodeError:
+                # If parsing fails, skip to the next match
+                continue
+        return text