How to capture the stderr from server, I saw there is a params named: errlog, its default value is sys.stderr, that caused any stderr from server side will be print in the console/terminal

I do not like the behavior, at least I want capture the error log from server and print with prefix(maybe "error-received: {original-err}")

but I cannot figure out how to use errlog param, I write a file-like object, something like this:

class ErrorPrefixTextIO(io.TextIOBase):
    def __init__(self, original_stream=None):
        self.original_stream = original_stream or sys.stderr
    
    def write(self, message: str) -> int:
        if message.strip():
            self.original_stream.write(f"error- {message}")
            self.original_stream.flush()
        return len(message)
    
    def flush(self) -> None:
        self.original_stream.flush()

    def fileno(self) -> int:
        return self.original_stream.fileno()

    def close(self) -> None:
        if hasattr(self.original_stream, 'close'):
            self.original_stream.close()

it's not work, seems the function write is ignored at all
besides that, I also try to assign a file object to errlog, it could work, the file is write with error from server, but I cannot add any prefix to original err message. any help, thanks