Bengt Richter wrote: > >>>> range(9)[4:-!0:-1] == range(5) > >True > Interesting, but wouldn't that last line be > >>> range(9)[4:-!0:-1] == range(5)[::-1]
Ups. Yes of course. > >Life can be simpler with unbound limits. > Hm, is "!0" a di-graph symbol for infinity? > What if we get full unicode on our screens? Should > it be rendered with unichr(0x221e) ? And how should > symbols be keyed in? Is there a standard mnemonic > way of using an ascii keyboard, something like typing > Japanese hiragana in some word processing programs? You can ask questions ;-) > I'm not sure about '!' since it already has some semantic > ties to negation and factorial and execution (not to mention > exclamation ;-) If !0 means infinity, what does !2 mean? > > Just rambling ... ;-) I'm not shure too. Probably Inf as a keyword is a much better choice. The only std-library module I found that used Inf was Decimal where Inf has the same meaning. Inf is quick to write ( just one more character than !0 ) and easy to parse for human readers. Rewriting the above statements/expressions leads to: >>> Inf Inf >>> Inf+1 Inf >>> Inf>n # if n is int True >>> Inf/Inf Traceback (...) ... UndefinedValue >>> Inf - Inf Traceback (...) ... UndefinedValue >>> -Inf -Inf >>> range(9)[4:Inf] == range(9)[4:] True >>> range(9)[4:-Inf:-1] == range(5)[::-1] True IMO it's still consice. Kay -- http://mail.python.org/mailman/listinfo/python-list
