Floating-Point Objects
**********************

type PyFloatObject

   This subtype of "PyObject" represents a Python floating-point
   object.

PyTypeObject PyFloat_Type
    * Part of the Stable ABI.*

   This instance of "PyTypeObject" represents the Python floating-
   point type.  This is the same object as "float" in the Python
   layer.

int PyFloat_Check(PyObject *p)

   Retorna verdadero si su argumento es un "PyFloatObject" o un
   subtipo de "PyFloatObject". Esta función siempre finaliza con
   éxito.

int PyFloat_CheckExact(PyObject *p)

   Retorna verdadero si su argumento es un "PyFloatObject", pero no un
   subtipo de "PyFloatObject". Esta función siempre finaliza con
   éxito.

PyObject *PyFloat_FromString(PyObject *str)
    *Return value: New reference.** Part of the Stable ABI.*

   Crea un objeto "PyFloatObject" basado en la cadena de caracteres en
   *str*, o "NULL" en caso de error.

PyObject *PyFloat_FromDouble(double v)
    *Return value: New reference.** Part of the Stable ABI.*

   Crea un objeto "PyFloatObject" a partir de *v*, o "NULL" en caso de
   error.

double PyFloat_AsDouble(PyObject *pyfloat)
    * Part of the Stable ABI.*

   Return a C double representation of the contents of *pyfloat*.  If
   *pyfloat* is not a Python floating-point object but has a
   "__float__()" method, this method will first be called to convert
   *pyfloat* into a float. If "__float__()" is not defined then it
   falls back to "__index__()". This method returns "-1.0" upon
   failure, so one should call "PyErr_Occurred()" to check for errors.

   Distinto en la versión 3.8: Utilice "__index__()" si está
   disponible.

double PyFloat_AS_DOUBLE(PyObject *pyfloat)

   Retorna una representación C double de los contenidos de *pyfloat*,
   pero sin verificación de errores.

PyObject *PyFloat_GetInfo(void)
    *Return value: New reference.** Part of the Stable ABI.*

   Retorna una instancia de *structseq* que contiene información sobre
   la precisión, los valores mínimos y máximos de un flotante. Es un
   contenedor reducido alrededor del archivo de encabezado "float.h".

double PyFloat_GetMax()
    * Part of the Stable ABI.*

   Retorna el máximo flotante finito representable *DBL_MAX* como C
   double.

double PyFloat_GetMin()
    * Part of the Stable ABI.*

   Retorna el flotante positivo normalizado mínimo *DBL_MIN* como C
   double.

Py_INFINITY

   This macro expands to a constant expression of type double, that
   represents the positive infinity.

   It is equivalent to the "INFINITY" macro from the C11 standard
   "<math.h>" header.

   Soft deprecated since version 3.15.

Py_NAN

   This macro expands to a constant expression of type double, that
   represents a quiet not-a-number (qNaN) value.

   On most platforms, this is equivalent to the "NAN" macro from the
   C11 standard "<math.h>" header.

Py_HUGE_VAL

   Equivalent to "INFINITY".

   Soft deprecated since version 3.14.

Py_MATH_E

   The definition (accurate for a double type) of the "math.e"
   constant.

Py_MATH_El

   High precision (long double) definition of "e" constant.

   Deprecated since version 3.15, will be removed in version 3.20.

Py_MATH_PI

   The definition (accurate for a double type) of the "math.pi"
   constant.

Py_MATH_PIl

   High precision (long double) definition of "pi" constant.

   Deprecated since version 3.15, will be removed in version 3.20.

Py_MATH_TAU

   The definition (accurate for a double type) of the "math.tau"
   constant.

   Added in version 3.6.

Py_RETURN_NAN

   Return "math.nan" from a function.

   On most platforms, this is equivalent to "return
   PyFloat_FromDouble(NAN)".

Py_RETURN_INF(sign)

   Return "math.inf" or "-math.inf" from a function, depending on the
   sign of *sign*.

   On most platforms, this is equivalent to the following:

      return PyFloat_FromDouble(copysign(INFINITY, sign));

Py_IS_FINITE(X)

   Return "1" if the given floating-point number *X* is finite, that
   is, it is normal, subnormal or zero, but not infinite or NaN.
   Return "0" otherwise.

   Soft deprecated since version 3.14: Use "isfinite" instead.

Py_IS_INFINITY(X)

   Return "1" if the given floating-point number *X* is positive or
   negative infinity.  Return "0" otherwise.

   Soft deprecated since version 3.14: Use "isinf" instead.

Py_IS_NAN(X)

   Return "1" if the given floating-point number *X* is a not-a-number
   (NaN) value.  Return "0" otherwise.

   Soft deprecated since version 3.14: Use "isnan" instead.


Funciones de empaquetado y desempaquetado
=========================================

The pack and unpack functions provide an efficient platform-
independent way to store floating-point values as byte strings. The
Pack routines produce a bytes string from a C double, and the Unpack
routines produce a C double from such a bytes string. The suffix (2, 4
or 8) specifies the number of bytes in the bytes string:

* The 2-byte format is the IEEE 754 binary16 half-precision format.

* The 4-byte format is the IEEE 754 binary32 single-precision format.

* The 8-byte format is the IEEE 754 binary64 double-precision format.

The NaN type may not be preserved on some platforms while unpacking
(signaling NaNs become quiet NaNs), for example on x86 systems in
32-bit mode.

It's assumed that the double type has the IEEE 754 binary64 double
precision format.  What happens if it's not true is partly accidental
(alas). On non-IEEE platforms with more precision, or larger dynamic
range, than IEEE 754 supports, not all values can be packed; on non-
IEEE platforms with less precision, or smaller dynamic range, not all
values can be unpacked.  The packing of special numbers like INFs and
NaNs (if such things exist on the platform) may not be handled
correctly, and attempting to unpack a bytes string containing an IEEE
INF or NaN may raise an exception.

Added in version 3.11.


Funciones de Empaquetado
------------------------

The pack routines write 2, 4 or 8 bytes, starting at *p*. *le* is an
int argument, non-zero if you want the bytes string in little-endian
format (exponent last, at "p+1", "p+3", or "p+6" and "p+7"), zero if
you want big-endian format (exponent first, at *p*). Use the
"PY_LITTLE_ENDIAN" constant to select the native endian: it is equal
to "0" on big endian processor, or "1" on little endian processor.

Valor retornado: "0" si todo está bien, "-1" si hay error (y se
establece una excepción, probablemente "OverflowError").

int PyFloat_Pack2(double x, char *p, int le)

   Empaquete un C doble como el formato de media precisión IEEE 754
   binary16.

int PyFloat_Pack4(double x, char *p, int le)

   Empaque un C doble como el formato de precisión simple IEEE 754
   binary32.

int PyFloat_Pack8(double x, char *p, int le)

   Empaque un C doble como el formato de doble precisión IEEE 754
   binary64.


Funciones de Desempaquetado
---------------------------

The unpack routines read 2, 4 or 8 bytes, starting at *p*.  *le* is an
int argument, non-zero if the bytes string is in little-endian format
(exponent last, at "p+1", "p+3" or "p+6" and "p+7"), zero if big-
endian (exponent first, at *p*). Use the "PY_LITTLE_ENDIAN" constant
to select the native endian: it is equal to "0" on big endian
processor, or "1" on little endian processor.

Valor retornado: Doble desempaquetado. Si hay error, "-1.0" y
"PyErr_Occurred()" es verdadero (y se establece una excepción,
probablemente "OverflowError").

double PyFloat_Unpack2(const char *p, int le)

   Descomprima el formato de media precisión IEEE 754 binary16 como un
   doble C.

double PyFloat_Unpack4(const char *p, int le)

   Descomprima el formato de precisión simple IEEE 754 binary32 como
   un doble C.

double PyFloat_Unpack8(const char *p, int le)

   Descomprima el formato de doble precisión IEEE 754 binary64 como un
   doble C.
