> >>> import decimal
> >>> decimal.getcontext().prec = 2
> >>> a = decimal.Decimal(2)
> >>> b = decimal.Decimal(3)
> >>> 100*a/b
> Decimal("67")
> >>> print 100*a/b
This prints "67".
> try -
>
> a=decimal.Decimal(2.0)
This will not work. You can't convert a float directly to a decimal.Decimal
(I believe this is so that you are forced to understand that there are
precision issues involved). 'a = decimal.Decimal("2.0")' will do what you
meant, though.
> b = decimal.Decimal(3)
> print 100*a/b
However, this will print out "67", just as the above did. The reason is the
one that Tim outlined: precision isn't the number of digits after the
decimal place - when I was at school the latter was called "decimal places"
and precision was "significant digits".
> Jacob- one slight flaw/quirk in Python is if you want floating point
> computations you have to specify a floating point.
[...]
> Same as writing 100/3.0 as opposed to 100/3. Try it.
Note that you can do 'from __future__ import division' and 100/3 will be the
same as 100/3.0 (and 100//3 will give you 3).
=Tony.Meyer
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