On Sat, May 19, 2018 at 8:25 AM, Chris Barker - NOAA Federal <chris.bar...@noaa.gov> wrote: >> I suppose you could argue that a "byte" is a patch of >> storage capable of holding a number from 0 to 255, as opposed to being >> the number itself, but that's getting rather existential :) > > No, I’m making the distinction that an eight bit byte is, well, eight > bits, that CAN represent a number from 0 to 255, or it can represent > any other data type — like one eighth of the bits in a float, for > instance. Or a bit field, or 1/2 a 16 bit int.
Since "bit" simply means "binary digit", that's like saying that a four-digit number isn't a number; it MIGHT represent a number, but it might represent one quarter of your credit card. Is "4564" less of a number for that reason? >> In Python, a "bytes" object represents a sequence of eight-bit units. >> When you subscript a bytes [1], you get back an integer with the value >> at that position. > > And when you print it, you get the ascii characters corresponding to > each byte.... That's because those numbers can often be used to represent characters. But they are really and truly numbers. (If you want to get down to brass tacks, a Unicode string could be treated as a sequence of 21-bit numbers. And in some languages, the "string" type is actually a highly-optimized version of 21-bit-number-array - or 32-bit, perhaps - with fully supported use-cases involving numerical (non-textual) data.) > So one element in a bytes object is no more an integer than a character.... Except that the bytestring b"\x00\x80\xff\x99" very clearly represents four numbers, but doesn't clearly represent any characters. >> Maybe I'm completely misunderstanding your statement here. > > Again, it doesn’t much matter, until you get to deciding how to > bitshift an entire bytes object. Bitshifting a sequence of bytes has nothing whatsoever to do with characters. It has to do with the individual numbers, and then you have to decide how you represent those as a collective: little-endian or big-endian. That's still a matter of numbers, not characters. ChrisA _______________________________________________ Python-ideas mailing list Python-ideas@python.org https://mail.python.org/mailman/listinfo/python-ideas Code of Conduct: http://python.org/psf/codeofconduct/
