xix reading and writing files introduction obtaining references to files reading files file contents iteration writing data to files using files and with statements the fileinput module renaming files deleting files random access files directories temporary files working with paths online resources exercise stream io introduction what is stream python streams iobase raw io/unbuffered io classes binary io/buffered io classes text stream classes stream properties closing streams returning to the open(function online resources exercise working with csv files introduction csv files the csv writer class the csv reader class the csv dictwriter class the csv dictreader class online resources exercises working with excel files introduction excel files