No need. The Python tutorial says mixing integers and decimals in
arithmetic is OK.
Note version 2.7.1 in the following.
cjk@mid-tower:~$ python
Python 2.7.1+ (r271:86832, Apr 11 2011, 18:13:53)
[GCC 4.5.2] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> from
Great info, thanks.
I hadn't thought of using Decimal type for integers that might be involved
in calculations. Can I simulate an integer with something like
"decimal(4,0)"? For quantity, I'd rather show "1" and not "1.0".
I forgot to say the Python tutorial says to use Decimal for financial
calcs to avoid rounding errors.
On Nov 27, 8:33 pm, pbreit wrote:
> I have some price fields specified as type 'decimal'. But am finding that I
> have to cast to 'float' do do any math (or the other to decimal.Decimal I
> guess
>> if ((form.vars.drops * form.vars.price_change) / form.vars.start_price) <
>> 0.20:
>> TypeError: can't multiply sequence by non-int of type 'Decimal'
I think form.vars.drops is a string.
I usually do something like Decimal(form.vars.somedecimalfield or 0)
For the benefit of Python newcomers r
Further examples:
quantity = 20.5
unit_cost = Decimal('2.99')
total_cost = Decimal(str(quantity)) * unit_cost
Or using the the example you provided above:
if ((form.vars.drops * form.vars.price_change) / form.vars.start_price) <
0.20
Assuming that form.vars.drops is a float, and form.vars.pri
>
> Is 'decimal' the best field type for storing financial amounts that will
> be involved in math calculations?
>
I've been doing a lot of research on the decimal vs float thing for a
while, and every database admin I've ever talked to about it says the same
thing: When it comes to financial
A version gotcha. This is OK on 2.7 but errors on 2.6:
>>> from decimal import *
>>> Decimal(1.0)
Decimal('1')
>>> from decimal import *
>>> Decimal(1.0)
Traceback (most recent call last):
File "", line 1, in
File "/usr/lib/python2.6/decimal.py", line 649, in __new__
"First convert the f
Also. I think this is a Python thing, not Web2py.
I'm at a loss for what data type I should use for currencies. I wasn't
expecting to run into these type problems (I'm a relative newbie!).
if form.vars.shipping_amount > (form.vars.start_price * Decimal(0.2)):
File "/usr/lib/python2.6/decim
Examples. shipping_amount and start_price both decimals.
if form.vars.shipping_amount > (form.vars.start_price * 0.2):
TypeError: unsupported operand type(s) for *: 'Decimal' and 'float'
drops is integer, price_change, start_price are decimals.
if ((form.vars.drops * form.vars.price_change)
You should not need any casting to do math computations. Can you
provide an example of what you do, perhaps something does not behave
as intended.
On Nov 27, 7:33 pm, pbreit wrote:
> I have some price fields specified as type 'decimal'. But am finding that I
> have to cast to 'float' do do any ma
Before the model in the model file will do.
On Jun 1, 3:39 pm, NetAdmin wrote:
> In which file do I declare the class?
>
> Thanks to everyone for their answers.
>
> On Jun 1, 3:10 pm, mdipierro wrote:
>
> > There is no need to use SQLCustomType in this case. Decimal is
> > supported by web2py ty
In which file do I declare the class?
Thanks to everyone for their answers.
On Jun 1, 3:10 pm, mdipierro wrote:
> There is no need to use SQLCustomType in this case. Decimal is
> supported by web2py type='decimal(n,m)' if the underliying database
> supports it. The problem is representation
There is no need to use SQLCustomType in this case. Decimal is
supported by web2py type='decimal(n,m)' if the underliying database
supports it. The problem is representation of the number.
Try this:
class IS_MYDECIMAL(IS_DECIMAL_IN_RANGE):
def formatter(self,value): return '%.2f' % value
an
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