Please explain what the wrong behaviour that you see is, and what you expect the right behaviour should be.

That code is intended to either keep any user-supplied Accept-Encoding header field, or send “Accept-Encoding: identity” if the field is not supplied.

If you are looking for a way to avoid adding this field entirely, see the lower level putrequest() and related methods. This is documented behaviour: <https://docs.python.org/2.7/library/httplib.html#httplib.HTTPConnection.putrequest>.