[Python-Dev] Re: long number multiplication
Nick Coghlan
ncoghlan at iinet.net.au
Tue Dec 7 09:39:06 CET 2004
Christopher A. Craig wrote:
>>i needed to implement this myself and was thinking of storing the digits
>>of an integer in a list.
>
>
> That's sort of what Python does except the "digits" are 15 bits,
> not base 10. Doing it in base 10 would be a huge pain because of the
> problems with base 10->base 2 conversion.
>
Indeed. Python's Decimal data type stores the digits in a list for ease of power
of 10 multiplication & rounding (the precision rules means a *lot* of that goes
on). However, it converts that list of digits to a long integer in order to do
addition, multiplication or division.
Cheers,
Nick.
--
Nick Coghlan | ncoghlan at email.com | Brisbane, Australia
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