It is written: "Proxy won't send cookie to real server, you can set jar = true to send it."
That's not the appropriate meaning of the jar option of request.
In request documentation, it states:
jar - if true, remember cookies for future use (or define your custom cookie jar; see examples section)
So, if jar=false, the cookies are still transmitted to the real server, and won't be cached by the proxy.
It is written: "Proxy won't send cookie to real server, you can set jar = true to send it." That's not the appropriate meaning of the jar option of request. In request documentation, it states: jar - if true, remember cookies for future use (or define your custom cookie jar; see examples section)
So, if jar=false, the cookies are still transmitted to the real server, and won't be cached by the proxy.