How about adding rational fraction to Python?

[Jeff Schwab]

Carl Banks wrote:
> On Feb 16, 3:03 pm, Lie <Lie.1... at gmail.com> wrote:
>> Although rationals have its limitations too, it is a much
>> better choice compared to floats/Decimals for most cases.
> 
> Maybe that's true for your use cases, but it's not true for most cases
> in general.
> 
> Rationals are pretty useless for almost any extended calculations,
> since the denominator tends to grow in size till it's practically
> unusbale,

What do you mean by "practically unusable?"  I heard similar arguments 
made against big integers at one point ("Primitive types are usually big 
enough, why risk performance?") but I fell in love with them when I 
first saw them in Smalltalk, and I'm glad Python supports them natively.