diff options
Diffstat (limited to 'Lib/decimal.py')
| -rw-r--r-- | Lib/decimal.py | 14 |
1 files changed, 11 insertions, 3 deletions
diff --git a/Lib/decimal.py b/Lib/decimal.py index 54e8cb4..1f5ff12 100644 --- a/Lib/decimal.py +++ b/Lib/decimal.py @@ -809,8 +809,10 @@ class Decimal(_numbers.Real, _numbers.Inexact): def __hash__(self): """x.__hash__() <==> hash(x)""" # Decimal integers must hash the same as the ints - # Non-integer decimals are normalized and hashed as strings - # Normalization assures that hash(100E-1) == hash(10) + # + # The hash of a nonspecial noninteger Decimal must depend only + # on the value of that Decimal, and not on its representation. + # For example: hash(Decimal("100E-1")) == hash(Decimal("10")). if self._is_special: if self._isnan(): raise TypeError('Cannot hash a NaN value.') @@ -826,7 +828,13 @@ class Decimal(_numbers.Real, _numbers.Inexact): # 2**64-1. So we can replace hash((-1)**s*c*10**e) with # hash((-1)**s*c*pow(10, e, 2**64-1). return hash((-1)**op.sign*op.int*pow(10, op.exp, 2**64-1)) - return hash(str(self.normalize())) + # The value of a nonzero nonspecial Decimal instance is + # faithfully represented by the triple consisting of its sign, + # its adjusted exponent, and its coefficient with trailing + # zeros removed. + return hash((self._sign, + self._exp+len(self._int), + self._int.rstrip('0'))) def as_tuple(self): """Represents the number as a triple tuple. |