[Python-checkins] r59254 - in python/trunk: Doc/c-api/concrete.rst Doc/library/sys.rst Include/floatobject.h Lib/test/test_sys.py Misc/NEWS Objects/floatobject.c Python/sysmodule.c
christian.heimes
python-checkins at python.org
Sat Dec 1 12:20:11 CET 2007
Author: christian.heimes
Date: Sat Dec 1 12:20:10 2007
New Revision: 59254
Modified:
python/trunk/Doc/c-api/concrete.rst
python/trunk/Doc/library/sys.rst
python/trunk/Include/floatobject.h
python/trunk/Lib/test/test_sys.py
python/trunk/Misc/NEWS
python/trunk/Objects/floatobject.c
python/trunk/Python/sysmodule.c
Log:
Feature #1534
Added PyFloat_GetMax(), PyFloat_GetMin() and PyFloat_GetInfo() to the float API.
Added a dictionary sys.float_info with information about the internal floating point type to the sys module.
Modified: python/trunk/Doc/c-api/concrete.rst
==============================================================================
--- python/trunk/Doc/c-api/concrete.rst (original)
+++ python/trunk/Doc/c-api/concrete.rst Sat Dec 1 12:20:10 2007
@@ -557,6 +557,23 @@
without error checking.
+.. cfunction:: PyObject* PyFloat_GetInfo(void)
+
+ Return a :ctype:`PyDictObject` object which contains information about the
+ precision, minimum and maximum values of a float. It's a thin wrapper
+ around the header file :file:`float.h`.
+
+
+.. cfunction:: double PyFloat_GetMax(void)
+
+ Return the maximum representable finite float *DBL_MAX* as C :ctype:`double`.
+
+
+.. cfunction:: double PyFloat_GetMin(void)
+
+ Return the minimum normalized positive float *DBL_MIN* as C :ctype:`double`.
+
+
.. _complexobjects:
Complex Number Objects
Modified: python/trunk/Doc/library/sys.rst
==============================================================================
--- python/trunk/Doc/library/sys.rst (original)
+++ python/trunk/Doc/library/sys.rst Sat Dec 1 12:20:10 2007
@@ -240,6 +240,48 @@
Use :mod:`atexit` instead.
+.. data:: float_info
+
+ A dict holding information about the float type. It contains low level
+ information about the precision and internal representation. Please study
+ your system's :file:`float.h` for more information.
+
+ +---------------------+--------------------------------------------------+
+ | key | explanation |
+ +=====================+==================================================+
+ | :const:`epsilon` | Difference between 1 and the next representable |
+ | | floating point number |
+ +---------------------+--------------------------------------------------+
+ | :const:`dig` | digits (see :file:`float.h`) |
+ +---------------------+--------------------------------------------------+
+ | :const:`mant_dig` | mantissa digits (see :file:`float.h`) |
+ +---------------------+--------------------------------------------------+
+ | :const:`max` | maximum representable finite float |
+ +---------------------+--------------------------------------------------+
+ | :const:`max_exp` | maximum int e such that radix**(e-1) is in the |
+ | | range of finite representable floats |
+ +---------------------+--------------------------------------------------+
+ | :const:`max_10_exp` | maximum int e such that 10**e is in the |
+ | | range of finite representable floats |
+ +---------------------+--------------------------------------------------+
+ | :const:`min` | Minimum positive normalizer float |
+ +---------------------+--------------------------------------------------+
+ | :const:`min_exp` | minimum int e such that radix**(e-1) is a |
+ | | normalized float |
+ +---------------------+--------------------------------------------------+
+ | :const:`min_10_exp` | minimum int e such that 10**e is a normalized |
+ | | float |
+ +---------------------+--------------------------------------------------+
+ | :const:`radix` | radix of exponent |
+ +---------------------+--------------------------------------------------+
+ | :const:`rounds` | addition rounds (see :file:`float.h`) |
+ +---------------------+--------------------------------------------------+
+
+ .. note::
+
+ The information in the table is simplified.
+
+
.. function:: getcheckinterval()
Return the interpreter's "check interval"; see :func:`setcheckinterval`.
Modified: python/trunk/Include/floatobject.h
==============================================================================
--- python/trunk/Include/floatobject.h (original)
+++ python/trunk/Include/floatobject.h Sat Dec 1 12:20:10 2007
@@ -21,6 +21,10 @@
#define PyFloat_Check(op) PyObject_TypeCheck(op, &PyFloat_Type)
#define PyFloat_CheckExact(op) (Py_Type(op) == &PyFloat_Type)
+PyAPI_FUNC(double) PyFloat_GetMax(void);
+PyAPI_FUNC(double) PyFloat_GetMin(void);
+PyAPI_FUNC(PyObject *) PyFloat_GetInfo(void);
+
/* Return Python float from string PyObject. Second argument ignored on
input, and, if non-NULL, NULL is stored into *junk (this tried to serve a
purpose once but can't be made to work as intended). */
Modified: python/trunk/Lib/test/test_sys.py
==============================================================================
--- python/trunk/Lib/test/test_sys.py (original)
+++ python/trunk/Lib/test/test_sys.py Sat Dec 1 12:20:10 2007
@@ -329,6 +329,8 @@
self.assert_(isinstance(sys.copyright, basestring))
self.assert_(isinstance(sys.exec_prefix, basestring))
self.assert_(isinstance(sys.executable, basestring))
+ self.assert_(isinstance(sys.float_info, dict))
+ self.assertEqual(len(sys.float_info), 11)
self.assert_(isinstance(sys.hexversion, int))
self.assert_(isinstance(sys.maxint, int))
if test.test_support.have_unicode:
Modified: python/trunk/Misc/NEWS
==============================================================================
--- python/trunk/Misc/NEWS (original)
+++ python/trunk/Misc/NEWS Sat Dec 1 12:20:10 2007
@@ -12,6 +12,9 @@
Core and builtins
-----------------
+- Issue #1534: Added ``PyFloat_GetMax()``, ``PyFloat_GetMin()`` and
+ ``PyFloat_GetInfo()`` to the float API.
+
- Issue #1521: On 64bit platforms, using PyArgs_ParseTuple with the t# of w#
format code incorrectly truncated the length to an int, even when
PY_SSIZE_T_CLEAN is set. The str.decode method used to return incorrect
@@ -301,6 +304,9 @@
Library
-------
+- Issue #1534: Added a dictionary sys.float_info with information about the
+ internal floating point type to the sys module.
+
- Issue 1429818: patch for trace and doctest modules so they play nicely
together.
Modified: python/trunk/Objects/floatobject.c
==============================================================================
--- python/trunk/Objects/floatobject.c (original)
+++ python/trunk/Objects/floatobject.c Sat Dec 1 12:20:10 2007
@@ -7,6 +7,7 @@
#include "Python.h"
#include <ctype.h>
+#include <float.h>
#if !defined(__STDC__)
extern double fmod(double, double);
@@ -46,6 +47,52 @@
return p + N_FLOATOBJECTS - 1;
}
+double
+PyFloat_GetMax(void)
+{
+ return DBL_MAX;
+}
+
+double
+PyFloat_GetMin(void)
+{
+ return DBL_MIN;
+}
+
+PyObject *
+PyFloat_GetInfo(void)
+{
+ PyObject *d, *tmp;
+
+#define SET_FLOAT_CONST(d, key, const) \
+ tmp = PyFloat_FromDouble(const); \
+ if (tmp == NULL) return NULL; \
+ if (PyDict_SetItemString(d, key, tmp)) return NULL; \
+ Py_DECREF(tmp)
+#define SET_INT_CONST(d, key, const) \
+ tmp = PyInt_FromLong(const); \
+ if (tmp == NULL) return NULL; \
+ if (PyDict_SetItemString(d, key, tmp)) return NULL; \
+ Py_DECREF(tmp)
+
+ d = PyDict_New();
+
+ SET_FLOAT_CONST(d, "max", DBL_MAX);
+ SET_INT_CONST(d, "max_exp", DBL_MAX_EXP);
+ SET_INT_CONST(d, "max_10_exp", DBL_MAX_10_EXP);
+ SET_FLOAT_CONST(d, "min", DBL_MIN);
+ SET_INT_CONST(d, "min_exp", DBL_MIN_EXP);
+ SET_INT_CONST(d, "min_10_exp", DBL_MIN_10_EXP);
+ SET_INT_CONST(d, "dig", DBL_DIG);
+ SET_INT_CONST(d, "mant_dig", DBL_MANT_DIG);
+ SET_FLOAT_CONST(d, "epsilon", DBL_EPSILON);
+ SET_INT_CONST(d, "radix", FLT_RADIX);
+ SET_INT_CONST(d, "rounds", FLT_ROUNDS);
+
+ return d;
+}
+
+
PyObject *
PyFloat_FromDouble(double fval)
{
Modified: python/trunk/Python/sysmodule.c
==============================================================================
--- python/trunk/Python/sysmodule.c (original)
+++ python/trunk/Python/sysmodule.c Sat Dec 1 12:20:10 2007
@@ -1169,6 +1169,8 @@
PyInt_FromLong(PyInt_GetMax()));
SET_SYS_FROM_STRING("py3kwarning",
PyBool_FromLong(Py_Py3kWarningFlag));
+ SET_SYS_FROM_STRING("float_info",
+ PyFloat_GetInfo());
#ifdef Py_USING_UNICODE
SET_SYS_FROM_STRING("maxunicode",
PyInt_FromLong(PyUnicode_GetMax()));
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