cpython/Doc/c-api/float.rst

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.. highlight:: c
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.. _floatobjects:
Floating Point Objects
----------------------
.. index:: object: floating point
.. c:type:: PyFloatObject
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This subtype of :c:type:`PyObject` represents a Python floating point object.
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.. c:var:: PyTypeObject PyFloat_Type
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This instance of :c:type:`PyTypeObject` represents the Python floating point
type. This is the same object as :class:`float` in the Python layer.
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.. c:function:: int PyFloat_Check(PyObject *p)
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Return true if its argument is a :c:type:`PyFloatObject` or a subtype of
:c:type:`PyFloatObject`. This function always succeeds.
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.. c:function:: int PyFloat_CheckExact(PyObject *p)
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Return true if its argument is a :c:type:`PyFloatObject`, but not a subtype of
:c:type:`PyFloatObject`. This function always succeeds.
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.. c:function:: PyObject* PyFloat_FromString(PyObject *str)
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Create a :c:type:`PyFloatObject` object based on the string value in *str*, or
``NULL`` on failure.
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.. c:function:: PyObject* PyFloat_FromDouble(double v)
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Create a :c:type:`PyFloatObject` object from *v*, or ``NULL`` on failure.
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.. c:function:: double PyFloat_AsDouble(PyObject *pyfloat)
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Return a C :c:type:`double` representation of the contents of *pyfloat*. If
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*pyfloat* is not a Python floating point object but has a :meth:`__float__`
method, this method will first be called to convert *pyfloat* into a float.
If ``__float__()`` is not defined then it falls back to :meth:`__index__`.
This method returns ``-1.0`` upon failure, so one should call
:c:func:`PyErr_Occurred` to check for errors.
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.. versionchanged:: 3.8
Use :meth:`__index__` if available.
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.. c:function:: double PyFloat_AS_DOUBLE(PyObject *pyfloat)
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Return a C :c:type:`double` representation of the contents of *pyfloat*, but
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without error checking.
.. c:function:: PyObject* PyFloat_GetInfo(void)
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Return a structseq instance 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`.
.. c:function:: double PyFloat_GetMax()
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Return the maximum representable finite float *DBL_MAX* as C :c:type:`double`.
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.. c:function:: double PyFloat_GetMin()
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Return the minimum normalized positive float *DBL_MIN* as C :c:type:`double`.