Guido van Rossum wrote:
However the *proposed* behavior (returns bytes if the arg was bytes, and returns str when the arg was str) is IMO sane, and no different than the polymorphism found in len() or many builtin operations.
My concern still is that it brings the bytes type into the status of another character string type, which is really bad, and will require further modifications to Python for the lifetime of 3.x. This is because applications will then regularly use byte strings for file names on Unix, and regular strings on Windows, and then expect the program to work the same without further modifications. The next question then will be environment variables and command line arguments, for which we then should provide two versions (e.g. sys.argv and sys.argvb; for os.environ, os.environ["PATH"] could mean something different from os.environ[b"PATH"]). And so on (passwd/group file, Tkinter, ...) Regards, Martin