Fixed Ast Python Repl for Chatgpt multiline commands (#2406)

Resolves issue https://github.com/hwchase17/langchain/issues/2252

---------

Co-authored-by: Abhik Singla <abhiksingla@microsoft.com>

langchain/tools/python/tool.py

@@ -50,6 +50,7 @@ class PythonAstREPLTool(BaseTool):
     )
     globals: Optional[Dict] = Field(default_factory=dict)
     locals: Optional[Dict] = Field(default_factory=dict)
+    sanitize_input: bool = True
 
     @root_validator(pre=True)
     def validate_python_version(cls, values: Dict) -> Dict:
@@ -65,6 +66,9 @@ class PythonAstREPLTool(BaseTool):
     def _run(self, query: str) -> str:
         """Use the tool."""
         try:
+            if self.sanitize_input:
+                # Remove the triple backticks from the query.
+                query = query.strip().strip("```")
             tree = ast.parse(query)
             module = ast.Module(tree.body[:-1], type_ignores=[])
             exec(ast.unparse(module), self.globals, self.locals)  # type: ignore