Connection reset by peer means the far end has terminated the connection.  You'll probably need to do some protocol analysis (wireshark or a similar tool) to find out why the connection is being dropped, or perhaps you can look at the far end logging.  As it is, there isn't enough information here to speculate as to a cause, or if there is any bug in the python library code.

(FYI Martin von Loewis hasn't had much time for CPython development lately, so I doubt he'll respond.)