On Sat, Sep 3, 2016, at 08:08, Martin Panter wrote: > On 1 September 2016 at 19:36, Ethan Furman <et...@stoneleaf.us> wrote: > > Deprecation of current "zero-initialised sequence" behaviour without removal > > ---------------------------------------------------------------------------- > > > > Currently, the ``bytes`` and ``bytearray`` constructors accept an integer > > argument and interpret it as meaning to create a zero-initialised sequence > > of the given size:: > > > > >>> bytes(3) > > b'\x00\x00\x00' > > >>> bytearray(3) > > bytearray(b'\x00\x00\x00') > > > > This PEP proposes to deprecate that behaviour in Python 3.6, but to leave > > it in place for at least as long as Python 2.7 is supported, possibly > > indefinitely. > > Can you clarify what “deprecate” means? Just add a note in the > documentation, or make calls trigger a DeprecationWarning as well? > Having bytearray(n) trigger a DeprecationWarning would be a minor > annoyance for code being compatible with Python 2 and 3, since > bytearray(n) is supported in Python 2.
I don't think bytearray(n) should be deprecated. I don't think that deprecating bytes(n) should entail also deprecating bytes(n). If I were designing these classes from scratch, I would not feel any impulse to make their constructors take the same arguments or have the same semantics, and I'm a bit unclear on what the reason for this decision was. I also don't think bytes.fromcount(n) is necessary. What's wrong with b'\0'*n? I could swear this has been answered before, but I don't recall what the answer was. I don't think the rationale mentioned in the PEP is an adequate explanation, it references an earlier decision, about a conceptually different class (it's an operation that's much more common with mutable classes than immutable ones - when's the last time you did (None,)*n relative to [None]*n), without actually explaining the real reason for either underlying decision (having bytearray(n) and having both classes take the same constructor arguments). I think that the functions we should add/keep are: bytes(values: Union[bytes, bytearray, Iterable[int]) bytearray(count : int) bytearray(values: Union[bytes, bytearray, Iterable[int]) bchr(integer) If, incidentally, we're going to add a .fromsize method, it'd be nice to add a way to provide a fill value other than 0. Also, maybe we should also add it for list and tuple (with the default value None)? For the (string, encoding) signatures, there's no good reason to keep them [TOOWTDI is str.encode] but no good reason to get rid of them either. _______________________________________________ Python-Dev mailing list Python-Dev@python.org https://mail.python.org/mailman/listinfo/python-dev Unsubscribe: https://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
