On Thu, 20 Mar 2008 15:09:08 +0100, Rolf van de Krol wrote: > John Machin wrote: >> Of course. You can chain comparisons as much as you like and is >> (semi-)sensible, e.g. >> > Hmm, 'of course' is not the correct word for it.
Not at all. The Original Poster tried something, and it worked. There were two alternatives: (1) Writing a == b == 2 is valid. (2) In the sixteen years that Python has been publicly available, with tens of thousands or more developers using it, nobody had noticed that Python had a bug in the compiler which incorrectly allowed a == b == 2 until Stef Mientki came along and discovered it. Given those two alternatives, (2) would be very surprising indeed, and so I think "of course" is well justified. That Python allows chaining comparisons this way isn't really surprising. That's a very natural thing to do. What's surprising is that other languages *don't* allow chaining comparisons, but force you to write the inefficient and (sometimes) confusing "(a == 2) and (b == 2)" instead. -- Steven -- http://mail.python.org/mailman/listinfo/python-list
