From fec6620dfb9b7e99b68c07b623235f87f5fd1a60 Mon Sep 17 00:00:00 2001 From: Mark Dickinson Date: Sat, 13 Nov 2010 10:27:38 +0000 Subject: Make Fraction(-1).__hash__() return -2 rather than -1 (see issue 10356). --- Lib/fractions.py | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-) (limited to 'Lib/fractions.py') diff --git a/Lib/fractions.py b/Lib/fractions.py index 51e67e22ea..8be52d2db8 100644 --- a/Lib/fractions.py +++ b/Lib/fractions.py @@ -528,12 +528,8 @@ class Fraction(numbers.Rational): return Fraction(round(self / shift) * shift) def __hash__(self): - """hash(self) + """hash(self)""" - Tricky because values that are exactly representable as a - float must have the same hash as that float. - - """ # XXX since this method is expensive, consider caching the result # In order to make sure that the hash of a Fraction agrees @@ -550,7 +546,8 @@ class Fraction(numbers.Rational): hash_ = _PyHASH_INF else: hash_ = abs(self._numerator) * dinv % _PyHASH_MODULUS - return hash_ if self >= 0 else -hash_ + result = hash_ if self >= 0 else -hash_ + return -2 if result == -1 else result def __eq__(a, b): """a == b""" -- cgit v1.2.1