[Tutor] why can't I find a function that givesme the sign of aninteger?

[Alan Gauld]

Orri,

> Eh you mean to say that in next Python versions someone could decide
> to change cmp(x,0) to another meaning? I bet my countryman (I'm from
> Holland too ;-) ) will veto that! Or else I'll pay him a visit :D

Its not another meaning, its the current meaning.
Kent is just pointing out that while the default cmp currently 
returns -1,0,1
there is nothing to stop a user defined cmp fom returning any negative or
positive number instead of -1,1. And cmp() calls any user defined cmp
under the hood.

In theory the standard cmp could be changed in future although its 
unlikely..
So while it is a nice trick it cannot be relied upon since it depends on a
detail of implementation. In practice I suspect you are fairly safe :-)

Alan G