I think that this is the correct place to ask, so I'll give a brief answer.
In python2 you had "strings" and "unicode strings". Python2 "strings" were 1-byte sequences, so it was impossibile to represent UNICODE code points beyond the few ASCII ones; therefore the "unicode string" was introduced. Strings could be used both for binary data, as well as for text. This confusion was deprecated, and in python3 there is a strict distinction between text and binary data. Strings (see <https://docs.python.org/3/library/stdtypes.html#text-sequence-type-str>) are sequences of UNICODE code points, and therefore are multi-byte sequences; 1-byte (8 bit) sequences are called "bytes" (see <https://docs.python.org/3/library/stdtypes.html#bytes-objects>) and are used for binary data. A very common mapping from python2 to python3 datatypes is str() → byte() unicode() → str() or if you prefer "abc" → b"abc" u"àèì" → "àèì" I regard pyownet as a low-level library, so I like to speak binary to the owserver, i.e. read and writes are bytes in python3 and str in python2. It is responsibility of the user to decode/encode the messages sent and received from owserver. OWFS node names (similarly to path names on a file system) instead are considered "non binary", and therefore are represented by strings. As what regards the practicality of using pyownet. - some nodes contain binary data: e.g. '/26.xxxxxxxxxxxx/pages/page.ALL', no decoding needed - numeric values can be converted directly, without the need of decoding: if owp is a proxy object you have e.g. >>> owp.read('/26.xxxxxxxxxxxx/temperature') b' 24.4688' >>> float(owp.read('/26.xxxxxxxxxxxx/temperature')) 24.4688 (this is because the float() class accepts both strings and bytes as input.) - text values should be decoded, but usually you can omit the encoding (which should be 'utf-8' or better 'ascii'): >>> owp.read("/structure/26/CA") b'y,000000,000001,rw,000001,s,' >>> owp.read("/structure/26/CA").decode() 'y,000000,000001,rw,000001,s,' Regards, Stefano > On 9 Oct 2019, at 22:44, Mick Sulley <m...@sulley.info> wrote: > > I am updating my python code from 2.7 to 3.7, using pyownet to communicate > with 1-wire. > > Reads and writes were strings in 2.7 but it seems they are binary in 3.7. I > can get around this by appending .decode('utf-8) and .encode('utf-8) to the > read and write functions, but I feel that I am making hard work of this. Is > there a better way to move reads and writes to Python3? > > I don't understand why the change has occurred, but I guess that is not a > question for this group. > > Thanks > > Mick > > > > _______________________________________________ > Owfs-developers mailing list > Owfs-developers@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/owfs-developers
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