Hmm, I think the idea of the mathematical symbol is interesting, but I think users are more interested in constructing a new, eventually-not-empty set, than referencing the empty set.
Semantically, I don't know if ∅() is satisfying. On Thu, Mar 17, 2022 at 08:19 Stéfane Fermigier <s...@fermigier.com> wrote: > The “correct” (according to Bourbaki) mathematical notation for an empty > set is “∅" (aka Unicode U+2205, or HTML ∅) > > Some time ago, for a project which had a lot of empty sets, I tried to use > this symbol as a short hand for set(). But: > > >>> ⦰ = set() > File "<stdin>", line 1 > ⦰ = set() > ^ > SyntaxError: invalid character '⦰' (U+29B0) > >>> ø = set() > >>> > > In other words, “⦰” is illegal as an identifier in Python (same for ⌀ aka > U+2300 DIAMETER SIGN), but “ø” (aka U+00F8 LATIN SMALL LETTER O WITH > STROKE) is legal ! > > So I used "⌀" instead of “⦰”, but I eventually dropped the whole idea > because, IIRC, some tools weren’t too happy with it. > > Still, I guess it wouldn’t be neither too hard nor two disruptive to > accept “⦰” as well as some other mathematical characters as identifiers in > Python. > > Since once of the application domains where Python shines nowadays is > mathematics (numerical, but also symbolic), I think it’s a shame that we > are preventing to use the proper unicode characters to designate some > universal mathematical objects. > > More info here: https://en.wikipedia.org/wiki/Null_sign > > S. > > On 13 Mar 2022 at 22:52:16, joao.p.f.batista...@gmail.com wrote: > >> Currently: >> l = [] # new empty list >> t = () # new empty tuple >> s = set() # new empty set (no clean and consistent way of initializing >> regarding the others) <<< >> d = {} # new empty dictionary >> >> Possible solution: >> s = {} # new empty set >> d = {:} # new empty dictionary (the ":" is a reference to key-value pairs) >> >> Current workaround at least for consistency: >> l = list() # new empty list >> t = tuple() # new empty tuple >> s = set() # new empty set >> d = dict() # new empty dictionary >> >> However, it doesn't feel right to not be able to initialize an empty set >> as cleanly and consistently as lists, tuples and dictionaries in both forms. >> _______________________________________________ >> Python-ideas mailing list -- python-ideas@python.org >> To unsubscribe send an email to python-ideas-le...@python.org >> https://mail.python.org/mailman3/lists/python-ideas.python.org/ >> Message archived at >> https://mail.python.org/archives/list/python-ideas@python.org/message/OPWEKLLGT6RWMEHC4SLEZ2LSRVCSS4GP/ >> Code of Conduct: http://python.org/psf/codeofconduct/ >> > > > -- > Stefane Fermigier - http://fermigier.com/ - http://twitter.com/sfermigier > - http://linkedin.com/in/sfermigier > Founder & CEO, Abilian - Enterprise Social Software - > http://www.abilian.com/ > Co-Founder & Co-Chairman, National Council for Free & Open Source Software > (CNLL) - http://cnll.fr/ > Co-Founder & Chairman, Association Professionnelle Européenne du Logiciel > Libre (APELL) - https://www.apell.info/ > Co-Founder & Spokesperson, European Cloud Industrial Alliance (EUCLIDIA) - > https://www.euclidia.eu/ > Founder, PyParis & PyData Paris - http://pyparis.org/ & http://pydata.fr/ > _______________________________________________ > Python-ideas mailing list -- python-ideas@python.org > To unsubscribe send an email to python-ideas-le...@python.org > https://mail.python.org/mailman3/lists/python-ideas.python.org/ > Message archived at > https://mail.python.org/archives/list/python-ideas@python.org/message/D3SSAHRXYHPAM4NW3E6XC3J3AL625PGL/ > Code of Conduct: http://python.org/psf/codeofconduct/ >
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