[Tutor] Range of float value

Daniel Yoo dyoo at cs.wpi.edu
Thu Feb 8 23:23:04 CET 2007



On Thu, 8 Feb 2007, Johan Geldenhuys wrote:

> OK, this what I wanted:
>
> I have a value: a = 48.41
>
> My lowValue is: lowValue = 48.35
> My highValue is : highvalue = 48.45

Range does not work on floats: it's meant to work on integers.



> I though that it could be possible to have a range between 48.35 and 48.45
> that could have a step of 0.1

There's an unsafe assumption here: in general, comparing floats for 
equality won't work unless you are very very careful.  See:

     http://www.python.org/doc/tut/node16.html

Because floats aren't directly comparable (at least under normal cases), 
that negates the idea of build a list of floats and comparing for equality 
against one of them.

However, Kent mentioned a solution that should work better, a chained 
comparison:

     a <= b <= c

which is true if b is squeezed between a and b.


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