-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 1/19/2015 11:36 AM, Ethan Furman wrote: > I was checking the documentation [1] to see where to put the new > information about bytes and bytearray %-formatting, and noticed > that /every/ operation that could modify a bytearray object in > place (e.g. center, capitalize, strip, etc.) instead returns a new > copy. > > The section just prior to that [2] does say, "As bytearray objects > are mutable, they support the mutable sequence operations ...". > > So it seems that when bytearray is treated as ascii data a new > bytearry is returned, and when bytearray is treated as a container > it is modified in place: > > New: > > bytearray(b'Chapter Title').center() bytearray(b' Chapter Title > ').replace(b' ', b'- * - ') > > In-place: > > bytearray(b'abc'][1] = ord(b'z') bytearray(b'def'] += b'ghi' > bytearray(b'123'] *= 3 > > I now have a minor dilemma: %-formatting is an ascii operation, > but it also has an in-place operator (%=) . . . so does %= modify > the bytearray in place just like += and *= do, or does it return a > new bytearray just like all the named ascii operations do? I do > not know which is more surprising: having one of the in-place > operators not work in place, or having an unnamed ascii-operation > not return a new copy. > > Thoughts?
I'd return a new copy (or, not implement it at all and let the default machinery call __mod__, and do the assignment). That's the least surprising to me, since the goal is to be compatible with 2.7's str %-formatting. - -- Eric. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQEcBAEBAgAGBQJUvThwAAoJENxauZFcKtNx/noIAIfIW2Ir4P9bQ9s7bdyJCvMj RlqfBhWVOjWZ52gK/CdTvpZZDlDUf+gh1JkbvggNvIQHUTy0IY9IxryWvNemfSce nzZxUhNKzx77f/oGTeGgqBBMZGvCsRCqYFbLBME5LDweiHAIL2MVGqF/SwkobrGq ruJjSBtNAl28IgpDj7kM7tT7/iXINk6XkVatNa2OxV2FOyYiIz+7Vs2HGpkltzhW g4qqGEvEpLOl1oRtmI/A3TDFjQgyHc1MKVax6PH/Nq2OMfnoS4hg+jTAzE6Eairh SmWyZUMjpTeHpCmUgx03WLh8iRTokfE2LN2KJuBN18iAT5EqC6sNTKZm9HX5odw= =D9zy -----END PGP SIGNATURE----- _______________________________________________ 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
