Perhaps the 'csv' module should do some sanity checking on the file passed to the reader.  The docs recommend that newline='' be used to open the file.  Maybe 'csv' could check that and warn if its not the case.  I poked around but it seems like io files don't have a handy property to check for that.  Further, maybe 'csv' could check if the file is a codecs.StreamReader object.  In that case, there is no way to turn off the extra newline characters and so that's probably a bug.