这是一个zmq的范例代码，可以用来学习rep和req模式(This is an example code for ZMQ that can be used to learn the rep and req patterns)

从底层实现的区块链商品溯源系统，基于python，用到zmq消息队列关键技术(The chain traceability system implemented from the bottom layer is based on python, which uses the key technology of ZMQ message queue.)