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Diffstat (limited to 'Doc/library/decimal.rst')
| -rw-r--r-- | Doc/library/decimal.rst | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/Doc/library/decimal.rst b/Doc/library/decimal.rst index d8ce673..7c03b6a 100644 --- a/Doc/library/decimal.rst +++ b/Doc/library/decimal.rst @@ -364,6 +364,24 @@ Decimal objects compared, sorted, and coerced to another type (such as :class:`float` or :class:`long`). + Decimal objects cannot generally be combined with floats in + arithmetic operations: an attempt to add a :class:`Decimal` to a + :class:`float`, for example, will raise a :exc:`TypeError`. + There's one exception to this rule: it's possible to use Python's + comparison operators to compare a :class:`float` instance ``x`` + with a :class:`Decimal` instance ``y``. Without this exception, + comparisons between :class:`Decimal` and :class:`float` instances + would follow the general rules for comparing objects of different + types described in the :ref:`expressions` section of the reference + manual, leading to confusing results. + + .. versionchanged:: 2.7 + A comparison between a :class:`float` instance ``x`` and a + :class:`Decimal` instance ``y`` now returns a result based on + the values of ``x`` and ``y``. In earlier versions ``x < y`` + returned the same (arbitrary) result for any :class:`Decimal` + instance ``x`` and any :class:`float` instance ``y``. + In addition to the standard numeric properties, decimal floating point objects also have a number of specialized methods: |