From 99d36f15639b9efa9ad110005605ae28ca65e829 Mon Sep 17 00:00:00 2001 From: Benjamin Peterson Date: Wed, 15 Apr 2009 21:26:36 +0000 Subject: [PATCH] call __float__ on str subclasses #5759 tests by R. David Murray --- Lib/test/test_float.py | 12 ++++++++++++ Misc/NEWS | 2 ++ Objects/floatobject.c | 4 +++- 3 files changed, 17 insertions(+), 1 deletion(-) diff --git a/Lib/test/test_float.py b/Lib/test/test_float.py index 2b6bd781cab..0b1ae96495b 100644 --- a/Lib/test/test_float.py +++ b/Lib/test/test_float.py @@ -82,11 +82,23 @@ class GeneralFloatCases(unittest.TestCase): def __float__(self): return 42 + # Issue 5759: __float__ not called on str subclasses (though it is on + # unicode subclasses). + class FooStr(str): + def __float__(self): + return float(str(self)) + 1 + + class FooUnicode(unicode): + def __float__(self): + return float(unicode(self)) + 1 + self.assertAlmostEqual(float(Foo0()), 42.) self.assertAlmostEqual(float(Foo1()), 42.) self.assertAlmostEqual(float(Foo2()), 42.) self.assertAlmostEqual(float(Foo3(21)), 42.) self.assertRaises(TypeError, float, Foo4(42)) + self.assertAlmostEqual(float(FooUnicode('8')), 9.) + self.assertAlmostEqual(float(FooStr('8')), 9.) def test_floatasratio(self): for f, ratio in [ diff --git a/Misc/NEWS b/Misc/NEWS index 4c30c03e5c8..8577a9f3c93 100644 --- a/Misc/NEWS +++ b/Misc/NEWS @@ -12,6 +12,8 @@ What's New in Python 2.7 alpha 1 Core and Builtins ----------------- +- Issue #5759: float() didn't call __float__ on str subclasses. + - Issue #5704: the "-3" command-line option now implies "-t". - Issue #2170: refactored xml.dom.minidom.normalize, increasing both diff --git a/Objects/floatobject.c b/Objects/floatobject.c index 881671c251c..4f041f4820c 100644 --- a/Objects/floatobject.c +++ b/Objects/floatobject.c @@ -1630,7 +1630,9 @@ float_new(PyTypeObject *type, PyObject *args, PyObject *kwds) return float_subtype_new(type, args, kwds); /* Wimp out */ if (!PyArg_ParseTupleAndKeywords(args, kwds, "|O:float", kwlist, &x)) return NULL; - if (PyString_Check(x)) + /* If it's a string, but not a string subclass, use + PyFloat_FromString. */ + if (PyString_CheckExact(x)) return PyFloat_FromString(x, NULL); return PyNumber_Float(x); }