使用java调用并运行python，但没有结果。processbuilder运行时

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class JavaPythonExample {
    public static void main(String[] args) {
        try {
            // 创建ProcessBuilder对象，并指定要执行的命令
            ProcessBuilder pb = new ProcessBuilder("python", "script.py");
            
            // 设置工作目录（可选）
            pb.directory(new File("path/to/script/directory"));
            
            // 启动外部进程
            Process process = pb.start();
            
            // 获取进程的输出流
            BufferedReader reader = new BufferedReader(new InputStreamReader(process.getInputStream()));
            
            // 读取输出结果
            String line;
            while ((line = reader.readLine()) != null) {
                System.out.println(line);
            }
            
            // 等待外部进程执行完毕
            int exitCode = process.waitFor();
            
            // 打印进程的退出码
            System.out.println("Exit Code: " + exitCode);
            
        } catch (IOException | InterruptedException e) {
            e.printStackTrace();
        }
    }
}