Steven D'Aprano added the comment: The docs are correct, you are just misinterpreting them. Which could, I guess, suggest the docs could do with improvement. With *one* argument, `str(obj)` returns a string via `object.__str__(obj)` or `repr(obj)`, whichever is defined. That includes the case where obj is a bytes object. *Only* in the two or three argument case where you explicitly provide either the encoding or errors parameter will bytes be decoded. But you must provide at least one of encoding or errors. If you provide neither, you have the one-argument form above. The default value for encoding is only relevant in cases like this: # encoding defaults to sys.getdefaultencoding() py> str(b'a', errors='ignore') 'a' Here's my suggested rewording: *** str(object='') -> str str(bytes_or_buffer [, encoding] [, errors]) -> str Create a new string object from the given object. If a single argument is given, returns the result of object.__str__() (if defined) or repr(object). If encoding or errors or both are specified, then the object must expose a data buffer that will be decoded using the given encoding and error handler. If errors is specified, the default encoding is sys.getdefaultencoding(). If encoding is specified, errors defaults to 'strict'. ---------- nosy: +steven.daprano versions: +Python 3.6, Python 3.7, Python 3.8, Python 3.9 _______________________________________ Python tracker https://bugs.python.org/issue39574 _______________________________________

Steven D'Aprano added the comment: Eric: sure, I'm happy with your modification. Alas, I'm currently having technology issues which prevents me from doing a PR. Would you care to do the honours? ---------- _______________________________________ Python tracker https://bugs.python.org/issue39574 _______________________________________

Eric V. Smith added the comment: I've created a PR and requested review from stevendaprano. I think the backports are correct. ---------- _______________________________________ Python tracker https://bugs.python.org/issue39574 _______________________________________

Steven D'Aprano added the comment: On Fri, Feb 07, 2020 at 12:33:45PM +0000, Serhiy Storchaka wrote:

Serhiy Storchaka added the comment:

See a discussion on Python-Dev: https://mail.python.org/archives/list/python-dev@python.org/message/YMIGWRUE...

I don't know whether the very odd calls str(encoding='spam') str(errors='eggs') str(encoding='spam', errors='eggs') are intentional or not. I suspect not: to me, it looks like an accident of implementation, not a deliberate feature. Under what circumstances would somebody intentionally provide an encoding and error handler when they aren't actually going to use them? There may be really unusual cases: args = () if condition else (mybytes,) str = str(*args, encoding='spam') but I doubt they are going to be either common or something we ought to encourage. Regardless of whether we deprecate and remove those three odd cases or not, I don't think we should bother documenting them. If anyone disagrees, and wants to document them, that's okay, but you can document them as a separate PR with a separate discussion. Let's just fix the confusion over the default encoding here and worry about other issues later. Don't let the perfect get in the way of the good enough for now :-) ---------- _______________________________________ Python tracker https://bugs.python.org/issue39574 _______________________________________

Change by Terry J. Reedy : ---------- versions: -Python 3.5, Python 3.6 _______________________________________ Python tracker https://bugs.python.org/issue39574 _______________________________________