Patched code sample

import pandas as pd
import ast

# Assume pyodide and llm are pre-configured external objects
class pyodide:
    def runPython(code, globals): pass
class llm:
    def generate_code(prompt): return "print(df.head())"

class CSV_Agents:
    def validatePythonCodeForDataFrame(self, pythonCode: str) -> dict:
        # FIX: The code is parsed into an Abstract Syntax Tree (AST) to detect disallowed operations, which is robust against obfuscation.
        try:
            tree = ast.parse(pythonCode)
        except SyntaxError as e:
            return {'error': f'Invalid Python code: {e}'}

        blocked_nodes = (ast.Import, ast.ImportFrom)
        blocked_calls = ('exec', 'eval', 'open', '__import__')

        for node in ast.walk(tree):
            if isinstance(node, blocked_nodes):
                return {'error': 'Imports are not allowed.'}
            if isinstance(node, ast.Call) and hasattr(node.func, 'id') and node.func.id in blocked_calls:
                return {'error': f'Calls to {node.func.id} are not allowed.'}
        return {'success': True}

    def run(self, untrusted_input: str, df: pd.DataFrame) -> str:
        prompt = f"Given the dataframe, analyze it based on this: {untrusted_input}"
        pythonCode = llm.generate_code(prompt)
        
        validation = self.validatePythonCodeForDataFrame(pythonCode)
        if validation.get('error'):
            return validation['error']

        # The generated code is executed in an environment with the dataframe
        output = pyodide.runPython(
            pythonCode,
            globals={'df': df}
        )
        return output