File "C:\test3.py", line 166, in m
    self.from_float(value * decimal.Decimal(1.0))/decimal.Decimal(1.0)
  File "c:\Python27\lib\decimal.py", line 691, in from_float
    n, d = abs(f).as_integer_ratio()
AttributeError: 'Decimal' object has no attribute 'as_integer_ratio'

line 691 in decimal.py 
      
n, d = abs(f).as_integer_ratio()

should be

n, d = _math.fabs(f).as_integer_ratio()

The problem seems to be that you're calling Decimal.from_float with a Decimal instance, not a float.  I'm not sure that should even work.  The Decimal constructor can create a decimal from an other decimal.

Your suggested solution probably would solve this exception, but I'm not sure it would be the good solution.  This way when creating a decimal from another decimal with from_float (which doesn't makes much sense, I think) could result in a loss of precision:

>>> Decimal(Decimal('0.999999999999999999999'))
Decimal('0.999999999999999999999')
>>> 
>>> math.fabs(Decimal('0.999999999999999999999'))
1.0
>>>

As Daniel says, from_float expects a float object, not a Decimal instance.

What did you want to achieve in the following line:

   self.from_float(value * decimal.Decimal(1.0))/decimal.Decimal(1.0)

?

By the way: in all current versions of Python, from_float is redundant:  you can create a Decimal directly from a float:


Python 2.7.1+ (2.7:d52b1faa7b11+, Mar 25 2011, 21:48:24) 
[GCC 4.2.1 (Apple Inc. build 5664)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> from decimal import Decimal
[64140 refs]
>>> Decimal(2.3)
Decimal('2.29999999999999982236431605997495353221893310546875')
[64149 refs]