On Tue, Apr 1, 2014 at 10:59 PM, Antoon Pardon <antoon.par...@rece.vub.ac.be> wrote: > On 01-04-14 12:58, Chris Angelico wrote: >> But because, in the future, Python may choose to create new operators, >> the simplest and safest way to ensure safety is to put a boundary on >> what can be operators and what can be names; Unicode character classes >> are perfect for this. It's also possible that all Unicode whitespace >> characters might become legal for indentation and separation (maybe >> they are already??), so obviously they're ruled out as identifiers; >> anyway, I honestly do not think people would want to use U+2007 FIGURE >> SPACE inside a name. So if we deny whitespace, and accept letters and >> digits, it makes good sense to deny mathematical symbols so as to keep >> them available for operators. (It also makes reasonable sense to >> *permit* mathematical symbols, thus allowing you to use them for >> functions/methods, in the same way that you can use "n", "o", and "t", >> but not "not"; but with word operators, the entire word has to be used >> as-is before it's a collision - with a symbolic one, any instance of >> that symbol inside a name will change parsing entirely. It's a >> trade-off, and Python's made a decision one way and not the other.) > > This mostly makes sense to me. The only caveat I have is that since we > also allow _ (U+005F LOW LINE) in names which belongs to the category > <puctuation, connector>, we should allow other symbols within this > category in a name. > > But I confess that is mostly personal taste, since I find names_like_this > ugly. Names-like-this look better to me but that wouldn't be workable > in python. But maybe there is some connector that would be aestetically > pleasing and not causing other problems.
That's reasonable. The Pc category doesn't have much in it: http://www.fileformat.info/info/unicode/category/Pc/list.htm If the definition of "characters permitted in identifiers" is derived exclusively from the Unicode categories, including Pc would make fine sense. Probably the definition should be: First character is L* or Pc, subsequent characters are L*, N*, or Pc, and either Mn or M* (combining characters). Or something like that. ChrisA -- https://mail.python.org/mailman/listinfo/python-list
