Merged revisions 71627 via svnmerge from

svn+ssh://pythondev@svn.python.org/python/trunk

........
  r71627 | benjamin.peterson | 2009-04-15 16:26:36 -0500 (Wed, 15 Apr 2009) | 4 lines

  call __float__ on str subclasses #5759

  tests by R. David Murray
........

diff --git a/Lib/test/test_float.py b/Lib/test/test_float.py
index 2d3b3575ccbb5a4111d633b5ed4a62f33ff8c747..123a69d404d3eb190a09b5fa88bfd27e91c8b6ee 100644 (file)
--- a/Lib/test/test_float.py
+++ b/Lib/test/test_float.py
@@ -78,11 +78,18 @@ 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
+
         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(FooStr('8')), 9.)
 
     def test_floatasratio(self):
         for f, ratio in [

diff --git a/Misc/NEWS b/Misc/NEWS
index cf07f860911dc8980501e8c50ad978926f5c0b62..866a5b557b775cf0eda9fe55fc660c952b738b79 100644 (file)
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -12,6 +12,8 @@ What's New in Python 3.1 beta 1?
 Core and Builtins
 -----------------
 
+- Issue #5759: float() didn't call __float__ on str subclasses.
+
 - The string.maketrans() function is deprecated; there is a new static method
   maketrans() on the bytes and bytearray classes.  This removes confusion about
   the types string.maketrans() is supposed to work with, and mirrors the

diff --git a/Objects/floatobject.c b/Objects/floatobject.c
index e77b2dc855ef6c92d93ba675a0890bc7c6095dab..2ef4d1a865a1364e55523b99625f3d0f14e209b8 100644 (file)
--- a/Objects/floatobject.c
+++ b/Objects/floatobject.c
@@ -1533,7 +1533,9 @@ 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 (PyUnicode_Check(x))
+       /* If it's a string, but not a string subclass, use
+          PyFloat_FromString. */
+       if (PyUnicode_CheckExact(x))
                return PyFloat_FromString(x);
        return PyNumber_Float(x);
 }