To share data that is valid for one request only from one function to another, a global variable is not good enough because it would break in threaded environments. Flask provides you with a special object that ensures it is only valid for the active request and that will return different values for each request. In a nutshell: it does the right thing, like it does for request and session.
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To share data that is valid for one request only from one function to another, a global variable is not good enough because it would break in threaded environments. Flask provides you with a special object that ensures it is only valid for the active request and that will return different values for each request. In a nutshell: it does the right thing, like it does for request and session.
你应该用session：http://flask.pocoo.org/docs/0.10/quickstart/#sessions
这是个关于flask会话持久化的问题。
你可以先参考一下这里：http://docs.jinkan.org/docs/flask/quickstart.html#sessions
g对象是在一个请求中共享变量，不同的请求对应的是不同的g对象。你这种情况的话应该使用session，session对象用于在不同的请求之间共享变量，最常见的就是实现登入登出的功能。
g是在一次请求的程序上下文和请求上下文之间共享数据的。当你第二次请求的时候g就不是上一个了。所以应该用session或者cookie