[Python-ideas] Decimal literal?

Cesare Di Mauro cesare.dimauro at a-tono.com
Thu Dec 4 11:19:12 CET 2008


On 04 dec 2008 at 10:56 AM, Raymond Hettinger <python at rcn.com> wrote:

>> But at least it will be more usable to have a short-hand for decimal
>> declaration:
>>
>> a = 1234.5678d
>
> How often do you put non-integer constants in real programs?

A few times indeed (except for strings). So why we are allowing
floats literals?

> Don't you find that most real decimal apps start with external
> data sources instead of all the data values being hard-coded
> in your program?

The same happens with any kind of application: except for
very common cases (like using integers and strings), constant
definitions are rare.

But working with financial applications, using decimal numerics
is a very common practice. Even if implementation is slow, we
prefer exact results over speed: there must be no possibility on
failing calculations when we are manipulating moneys.

If you take a look at other languages / IDEs, like Delphi or CBuilder,
there's support for BCD-like type, but I never appreciated the
need to import its library to use it on my applications.

Also keep in mind that having the possibility to define literals for
a set of types can help a lot in generating a more optimized
bytecode.
That's because we can do a more aggressive static analysis
(a field were can be done a lot of work to improve the
performance of the language).

Cheers
Cesare



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