# 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.

  Detalles de implementación de CPython: This function always succeeds in CPython.

### 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`).

Detalles de implementación de CPython: These functions always succeed in CPython.

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.