server.expect("END") needs to be in a finally block

In the _get() function, the server.expect("END") statement needs to be in a finally block, so that it gets executed no matter what. When the _recv_value() function throws an exception, then "END" remains in the socket's buffer, which causes the next _get() command to return (None,None), then the call after that to return the previous call's data.

In my specific case, _recv_value() was occasionally throwing exceptions from decompress() when it got bad data to decompress, which is what was causing this. The fact that the data to decompress was bad is my own fault, but this could happen to others and is very easy to fix.