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"""Decimal fixed-point and floating-point arithmetic.

This is an implementation of decimal floating-point arithmetic based on

the General Decimal Arithmetic Specification:

http://speleotrove.com/decimal/decarith.html

and IEEE standard 854-1987:

http://en.wikipedia.org/wiki/IEEE_854-1987

Decimal floating point has finite precision with arbitrarily large bounds.

The purpose of this module is to support arithmetic using familiar

"schoolhouse" rules and to avoid some of the tricky representation

issues associated with binary floating point. The package is especially

useful for financial applications or for contexts where users have

expectations that are at odds with binary floating point (for instance,

in binary floating point, 1.00 % 0.1 gives 0.09999999999999995 instead

of 0.0; Decimal('1.00') % Decimal('0.1') returns the expected

Decimal('0.00')).

Here are some examples of using the decimal module:

>>> from decimal import *

>>> setcontext(ExtendedContext)

>>> Decimal(0)

Decimal('0')

>>> Decimal('1')

Decimal('1')

>>> Decimal('-.0123')

Decimal('-0.0123')

>>> Decimal(123456)

Decimal('123456')

>>> Decimal('123.45e12345678')

Decimal('1.2345E+12345680')

>>> Decimal('1.33') + Decimal('1.27')

Decimal('2.60')

>>> Decimal('12.34') + Decimal('3.87') - Decimal('18.41')

Decimal('-2.20')

>>> dig = Decimal(1)

>>> print(dig / Decimal(3))

0.333333333

>>> getcontext().prec = 18

>>> print(dig / Decimal(3))

0.333333333333333333

>>> print(dig.sqrt())

>>> print(Decimal(3).sqrt())

1.73205080756887729

>>> print(Decimal(3) ** 123)

4.85192780976896427E+58

>>> inf = Decimal(1) / Decimal(0)

>>> print(inf)

Infinity

>>> neginf = Decimal(-1) / Decimal(0)

>>> print(neginf)

-Infinity

>>> print(neginf + inf)

NaN

>>> print(neginf * inf)

-Infinity

>>> print(dig / 0)

Infinity

>>> getcontext().traps[DivisionByZero] = 1

>>> print(dig / 0)

Traceback (most recent call last):

...

decimal.DivisionByZero: x / 0

>>> c = Context()

>>> c.traps[InvalidOperation] = 0