Fixed a bug in reporting Python code validation (#11522)

- **Description:** fixed a bug in pal-chain when it reports Python
    code validation errors. When node.func does not have any ids, the
    original code tried to print node.func.id in raising ValueError.
- **Issue:** n/a,
- **Dependencies:** no dependencies,
- **Tag maintainer:** @hazzel-cn, @eyurtsev
- **Twitter handle:** @lazyswamp

---------

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

libs/experimental/langchain_experimental/pal_chain/base.py

@@ -226,24 +226,26 @@ class PALChain(Chain):
             or not code_validations.allow_imports
         ):
             for node in ast.walk(code_tree):
-                if (
+                if (not code_validations.allow_command_exec) and isinstance(
-                    (not code_validations.allow_command_exec)
+                    node, ast.Call
-                    and isinstance(node, ast.Call)
+                ):
-                    and (
+                    if (
-                        (
+                        hasattr(node.func, "id")
-                            hasattr(node.func, "id")
+                        and node.func.id in COMMAND_EXECUTION_FUNCTIONS
-                            and node.func.id in COMMAND_EXECUTION_FUNCTIONS
+                    ):
+                        raise ValueError(
+                            f"Found illegal command execution function "
+                            f"{node.func.id} in code {code}"
                         )
-                        or (
+
-                            isinstance(node.func, ast.Attribute)
+                    if (
-                            and node.func.attr in COMMAND_EXECUTION_FUNCTIONS
+                        isinstance(node.func, ast.Attribute)
+                        and node.func.attr in COMMAND_EXECUTION_FUNCTIONS
+                    ):
+                        raise ValueError(
+                            f"Found illegal command execution function "
+                            f"{node.func.attr} in code {code}"
                         )
-                    )
-                ):
-                    raise ValueError(
-                        f"Found illegal command execution function "
-                        f"{node.func.id} in code {code}"
-                    )
 
                 if (not code_validations.allow_imports) and (
                     isinstance(node, ast.Import) or isinstance(node, ast.ImportFrom)