needshere are few things you should know about these three open argumentsfilename as mentioned earlierfilenames can include an explicit directory path to refer to files in arbitrary places on your computerif they do notthey are taken to be names relative to the current working directory (described in the prior in generalmost filename forms you can type in your system shell will work in an open call for instancea relative filename argument \temp\spam txton windows means spam txt in the temp subdirectory of the current working directory' parent--up oneand down to directory temp open mode the open function accepts other modestoosome of which we'll see at work later in this + +and ato open for reads and writesand any mode string with to designate binary mode for instancemode rmeans both reads and writes are allowed on an existing filewallows reads and writes but creates the file anewerasing any prior contentrb and wb read and write data in binary mode without any translationsand wband + both combine binary mode and input plus output in generalthe mode string defaults to for read but can be for write and for appendand you may add for updateas well as or for binary or text modeorder is largely irrelevant as we'll see later in this the modes are often used in conjunction with the file object' seek method to achieve random read/write access regardless of modefile contents are always strings in python programs--read methods return stringand we pass string to write methods as also described laterthoughthe mode string implies which type of string is usedstr for text mode or bytes and other byte string types for binary mode buffering policy the open call also takes an optional third buffering policy argument which lets you control buffering for the file--the way that data is queued up before being transferredto boost performance if passed means file operations are unbuffered (data is transferred immediatelybut allowed in binary modes only) means they are line bufferedand any other positive value means to use full buffering (which is the defaultif no buffering argument is passedas usualpython' library manual and reference texts have the full story on additional open arguments beyond these three for instancethe open call supports additional arguments related to the end-of-line mapping behavior and the automatic unicode encoding of content performed for text-mode files since we'll discuss both of these concepts in the next sectionlet' move ahead file tools