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christian.heimes
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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. git-svn-id: http://svn.python.org/projects/python/trunk@59254 6015fed2-1504-0410-9fe1-9d1591cc4771
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‎Doc/c-api/concrete.rst‎

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@@ -557,6 +557,23 @@ Floating Point Objects
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without error checking.
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.. cfunction:: PyObject* PyFloat_GetInfo(void)
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Return a :ctype:`PyDictObject` object which contains information about the
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precision, minimum and maximum values of a float. It's a thin wrapper
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around the header file :file:`float.h`.
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.. cfunction:: double PyFloat_GetMax(void)
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Return the maximum representable finite float *DBL_MAX* as C :ctype:`double`.
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.. cfunction:: double PyFloat_GetMin(void)
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Return the minimum normalized positive float *DBL_MIN* as C :ctype:`double`.
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.. _complexobjects:
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Complex Number Objects

‎Doc/library/sys.rst‎

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@@ -240,6 +240,48 @@ always available.
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Use :mod:`atexit` instead.
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.. data:: float_info
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A dict holding information about the float type. It contains low level
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information about the precision and internal representation. Please study
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your system's :file:`float.h` for more information.
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+---------------------+--------------------------------------------------+
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| key | explanation |
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+=====================+==================================================+
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| :const:`epsilon` | Difference between 1 and the next representable |
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| | floating point number |
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+---------------------+--------------------------------------------------+
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| :const:`dig` | digits (see :file:`float.h`) |
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+---------------------+--------------------------------------------------+
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| :const:`mant_dig` | mantissa digits (see :file:`float.h`) |
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+---------------------+--------------------------------------------------+
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| :const:`max` | maximum representable finite float |
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+---------------------+--------------------------------------------------+
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| :const:`max_exp` | maximum int e such that radix**(e-1) is in the |
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| | range of finite representable floats |
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+---------------------+--------------------------------------------------+
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| :const:`max_10_exp` | maximum int e such that 10**e is in the |
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| | range of finite representable floats |
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+---------------------+--------------------------------------------------+
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| :const:`min` | Minimum positive normalizer float |
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+---------------------+--------------------------------------------------+
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| :const:`min_exp` | minimum int e such that radix**(e-1) is a |
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| | normalized float |
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+---------------------+--------------------------------------------------+
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| :const:`min_10_exp` | minimum int e such that 10**e is a normalized |
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| | float |
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+---------------------+--------------------------------------------------+
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| :const:`radix` | radix of exponent |
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+---------------------+--------------------------------------------------+
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| :const:`rounds` | addition rounds (see :file:`float.h`) |
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+---------------------+--------------------------------------------------+
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.. note::
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The information in the table is simplified.
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.. function:: getcheckinterval()
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Return the interpreter's "check interval"; see :func:`setcheckinterval`.

‎Include/floatobject.h‎

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@@ -21,6 +21,10 @@ PyAPI_DATA(PyTypeObject) PyFloat_Type;
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#define PyFloat_Check(op) PyObject_TypeCheck(op, &PyFloat_Type)
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#define PyFloat_CheckExact(op) (Py_Type(op) == &PyFloat_Type)
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PyAPI_FUNC(double) PyFloat_GetMax(void);
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PyAPI_FUNC(double) PyFloat_GetMin(void);
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PyAPI_FUNC(PyObject *) PyFloat_GetInfo(void);
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/* Return Python float from string PyObject. Second argument ignored on
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input, and, if non-NULL, NULL is stored into *junk (this tried to serve a
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purpose once but can't be made to work as intended). */

‎Lib/test/test_sys.py‎

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@@ -329,6 +329,8 @@ def test_attributes(self):
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self.assert_(isinstance(sys.copyright, basestring))
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self.assert_(isinstance(sys.exec_prefix, basestring))
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self.assert_(isinstance(sys.executable, basestring))
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self.assert_(isinstance(sys.float_info, dict))
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self.assertEqual(len(sys.float_info), 11)
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self.assert_(isinstance(sys.hexversion, int))
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self.assert_(isinstance(sys.maxint, int))
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if test.test_support.have_unicode:

‎Misc/NEWS‎

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@@ -12,6 +12,9 @@ What's New in Python 2.6 alpha 1?
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Core and builtins
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-----------------
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- Issue #1534: Added ``PyFloat_GetMax()``, ``PyFloat_GetMin()`` and
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``PyFloat_GetInfo()`` to the float API.
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- Issue #1521: On 64bit platforms, using PyArgs_ParseTuple with the t# of w#
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format code incorrectly truncated the length to an int, even when
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PY_SSIZE_T_CLEAN is set. The str.decode method used to return incorrect
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Library
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-------
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- Issue #1534: Added a dictionary sys.float_info with information about the
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internal floating point type to the sys module.
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- Issue 1429818: patch for trace and doctest modules so they play nicely
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together.
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‎Objects/floatobject.c‎

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#include "Python.h"
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#include <ctype.h>
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#include <float.h>
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#if !defined(__STDC__)
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extern double fmod(double, double);
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return p + N_FLOATOBJECTS - 1;
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}
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double
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PyFloat_GetMax(void)
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{
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return DBL_MAX;
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}
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double
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PyFloat_GetMin(void)
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{
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return DBL_MIN;
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}
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PyObject *
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PyFloat_GetInfo(void)
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{
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PyObject *d, *tmp;
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#define SET_FLOAT_CONST(d, key, const) \
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tmp = PyFloat_FromDouble(const); \
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if (tmp == NULL) return NULL; \
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if (PyDict_SetItemString(d, key, tmp)) return NULL; \
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Py_DECREF(tmp)
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#define SET_INT_CONST(d, key, const) \
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tmp = PyInt_FromLong(const); \
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if (tmp == NULL) return NULL; \
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if (PyDict_SetItemString(d, key, tmp)) return NULL; \
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Py_DECREF(tmp)
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d = PyDict_New();
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SET_FLOAT_CONST(d, "max", DBL_MAX);
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SET_INT_CONST(d, "max_exp", DBL_MAX_EXP);
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SET_INT_CONST(d, "max_10_exp", DBL_MAX_10_EXP);
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SET_FLOAT_CONST(d, "min", DBL_MIN);
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SET_INT_CONST(d, "min_exp", DBL_MIN_EXP);
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SET_INT_CONST(d, "min_10_exp", DBL_MIN_10_EXP);
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SET_INT_CONST(d, "dig", DBL_DIG);
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SET_INT_CONST(d, "mant_dig", DBL_MANT_DIG);
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SET_FLOAT_CONST(d, "epsilon", DBL_EPSILON);
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SET_INT_CONST(d, "radix", FLT_RADIX);
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SET_INT_CONST(d, "rounds", FLT_ROUNDS);
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return d;
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}
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PyObject *
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PyFloat_FromDouble(double fval)
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{

‎Python/sysmodule.c‎

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PyInt_FromLong(PyInt_GetMax()));
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SET_SYS_FROM_STRING("py3kwarning",
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PyBool_FromLong(Py_Py3kWarningFlag));
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SET_SYS_FROM_STRING("float_info",
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PyFloat_GetInfo());
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#ifdef Py_USING_UNICODE
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SET_SYS_FROM_STRING("maxunicode",
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PyInt_FromLong(PyUnicode_GetMax()));

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