Patched code sample

import sys
from io import StringIO
from typing import Any
from RestrictedPython import compile_restricted, safe_builtins

# Placeholder for the external 'pb' module and its 'CheckResult' class
pb = type("pb", (), {"CheckResult": lambda **kwargs: None})


class PythonREPL:
    def __init__(self, globals: dict | None = None, locals: dict | None = None):
        self._globals = globals if globals is not None else {}
        self._locals = locals if locals is not None else {}

    def run(self, code: str) -> pb.CheckResult:
        old_stdout = sys.stdout
        sys.stdout = mystdout = StringIO()
        old_stderr = sys.stderr
        sys.stderr = mystderr = StringIO()
        try:
            # FIX: Compile the code in a restricted environment to prevent execution of malicious code.
            byte_code = compile_restricted(code, "<string>", "exec")
            safe_globals = {"__builtins__": safe_builtins}
            exec(byte_code, safe_globals, self._locals)
        except Exception:
            pass
        finally:
            sys.stdout = old_stdout
            sys.stderr = old_stderr
        return pb.CheckResult(
            stdout=mystdout.getvalue(),
            stderr=mystderr.getvalue(),
        )