From 393f1ff62e032f20adaed2613a9e2d2d6bcb1eb3 Mon Sep 17 00:00:00 2001 From: Elias Zamaria Date: Sun, 26 Aug 2018 23:59:28 -0700 Subject: bpo-32968: Make modulo and floor division involving Fraction and float consistent with other operations (#5956) Make mixed-type `%` and `//` operations involving `Fraction` and `float` objects behave like all other mixed-type arithmetic operations: first the `Fraction` object is converted to a `float`, then the `float` operation is performed as normal. This fixes some surprising corner cases, like `Fraction('1/3') % inf` giving a NaN. Thanks Elias Zamaria for the patch. --- Lib/fractions.py | 13 ++++--------- Lib/test/test_fractions.py | 10 +++++++--- Misc/ACKS | 1 + .../next/Library/2018-03-18-15-57-32.bpo-32968.E4G7BO.rst | 1 + 4 files changed, 13 insertions(+), 12 deletions(-) create mode 100644 Misc/NEWS.d/next/Library/2018-03-18-15-57-32.bpo-32968.E4G7BO.rst diff --git a/Lib/fractions.py b/Lib/fractions.py index 8330202..e0a024a 100644 --- a/Lib/fractions.py +++ b/Lib/fractions.py @@ -427,23 +427,18 @@ class Fraction(numbers.Rational): __truediv__, __rtruediv__ = _operator_fallbacks(_div, operator.truediv) - def __floordiv__(a, b): + def _floordiv(a, b): """a // b""" return math.floor(a / b) - def __rfloordiv__(b, a): - """a // b""" - return math.floor(a / b) + __floordiv__, __rfloordiv__ = _operator_fallbacks(_floordiv, operator.floordiv) - def __mod__(a, b): + def _mod(a, b): """a % b""" div = a // b return a - b * div - def __rmod__(b, a): - """a % b""" - div = a // b - return a - b * div + __mod__, __rmod__ = _operator_fallbacks(_mod, operator.mod) def __pow__(a, b): """a ** b diff --git a/Lib/test/test_fractions.py b/Lib/test/test_fractions.py index 7905c36..452f181 100644 --- a/Lib/test/test_fractions.py +++ b/Lib/test/test_fractions.py @@ -401,15 +401,19 @@ class FractionTest(unittest.TestCase): self.assertTypedEquals(10.0 + 0j, (1.0 + 0j) / F(1, 10)) self.assertTypedEquals(0, F(1, 10) // 1) - self.assertTypedEquals(0, F(1, 10) // 1.0) + self.assertTypedEquals(0.0, F(1, 10) // 1.0) self.assertTypedEquals(10, 1 // F(1, 10)) self.assertTypedEquals(10**23, 10**22 // F(1, 10)) - self.assertTypedEquals(10, 1.0 // F(1, 10)) + self.assertTypedEquals(1.0 // 0.1, 1.0 // F(1, 10)) self.assertTypedEquals(F(1, 10), F(1, 10) % 1) self.assertTypedEquals(0.1, F(1, 10) % 1.0) self.assertTypedEquals(F(0, 1), 1 % F(1, 10)) - self.assertTypedEquals(0.0, 1.0 % F(1, 10)) + self.assertTypedEquals(1.0 % 0.1, 1.0 % F(1, 10)) + self.assertTypedEquals(0.1, F(1, 10) % float('inf')) + self.assertTypedEquals(float('-inf'), F(1, 10) % float('-inf')) + self.assertTypedEquals(float('inf'), F(-1, 10) % float('inf')) + self.assertTypedEquals(-0.1, F(-1, 10) % float('-inf')) # No need for divmod since we don't override it. diff --git a/Misc/ACKS b/Misc/ACKS index 8c8d954..82fbc92 100644 --- a/Misc/ACKS +++ b/Misc/ACKS @@ -1814,6 +1814,7 @@ Masazumi Yoshikawa Arnaud Ysmal Bernard Yue Moshe Zadka +Elias Zamaria Milan Zamazal Artur Zaprzala Mike Zarnstorff diff --git a/Misc/NEWS.d/next/Library/2018-03-18-15-57-32.bpo-32968.E4G7BO.rst b/Misc/NEWS.d/next/Library/2018-03-18-15-57-32.bpo-32968.E4G7BO.rst new file mode 100644 index 0000000..16bf2f3 --- /dev/null +++ b/Misc/NEWS.d/next/Library/2018-03-18-15-57-32.bpo-32968.E4G7BO.rst @@ -0,0 +1 @@ +Modulo and floor division involving Fraction and float should return float. -- cgit v0.12