121 lines
3.3 KiB
ReStructuredText
121 lines
3.3 KiB
ReStructuredText
.. highlightlang:: c
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.. _floatobjects:
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Floating Point Objects
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----------------------
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.. index:: object: floating point
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.. ctype:: PyFloatObject
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This subtype of :ctype:`PyObject` represents a Python floating point object.
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.. cvar:: PyTypeObject PyFloat_Type
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.. index:: single: FloatType (in modules types)
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This instance of :ctype:`PyTypeObject` represents the Python floating point
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type. This is the same object as ``float`` and ``types.FloatType``.
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.. cfunction:: int PyFloat_Check(PyObject *p)
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Return true if its argument is a :ctype:`PyFloatObject` or a subtype of
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:ctype:`PyFloatObject`.
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.. versionchanged:: 2.2
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Allowed subtypes to be accepted.
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.. cfunction:: int PyFloat_CheckExact(PyObject *p)
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Return true if its argument is a :ctype:`PyFloatObject`, but not a subtype of
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:ctype:`PyFloatObject`.
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.. versionadded:: 2.2
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.. cfunction:: PyObject* PyFloat_FromString(PyObject *str, char **pend)
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Create a :ctype:`PyFloatObject` object based on the string value in *str*, or
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*NULL* on failure. The *pend* argument is ignored. It remains only for
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backward compatibility.
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.. cfunction:: PyObject* PyFloat_FromDouble(double v)
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Create a :ctype:`PyFloatObject` object from *v*, or *NULL* on failure.
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.. cfunction:: double PyFloat_AsDouble(PyObject *pyfloat)
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Return a C :ctype:`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__`
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method, this method will first be called to convert *pyfloat* into a float.
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This method returns ``-1.0`` upon failure, so one should call
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:cfunc:`PyErr_Occurred` to check for errors.
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.. cfunction:: double PyFloat_AS_DOUBLE(PyObject *pyfloat)
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Return a C :ctype:`double` representation of the contents of *pyfloat*, but
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without error checking.
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.. cfunction:: PyObject* PyFloat_GetInfo(void)
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Return a structseq instance 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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.. versionadded:: 2.6
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.. cfunction:: double PyFloat_GetMax()
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Return the maximum representable finite float *DBL_MAX* as C :ctype:`double`.
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.. versionadded:: 2.6
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.. cfunction:: double PyFloat_GetMin()
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Return the minimum normalized positive float *DBL_MIN* as C :ctype:`double`.
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.. versionadded:: 2.6
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.. cfunction:: int PyFloat_ClearFreeList()
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Clear the float free list. Return the number of items that could not
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be freed.
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.. versionadded:: 2.6
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.. cfunction:: void PyFloat_AsString(char *buf, PyFloatObject *v)
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Convert the argument *v* to a string, using the same rules as
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:func:`str`. The length of *buf* should be at least 100.
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This function is unsafe to call because it writes to a buffer whose
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length it does not know.
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.. deprecated:: 2.7
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Use :func:`PyObject_Str` or :func:`PyOS_double_to_string` instead.
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.. cfunction:: void PyFloat_AsReprString(char *buf, PyFloatObject *v)
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Same as PyFloat_AsString, except uses the same rules as
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:func:`repr`. The length of *buf* should be at least 100.
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This function is unsafe to call because it writes to a buffer whose
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length it does not know.
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.. deprecated:: 2.7
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Use :func:`PyObject_Repr` or :func:`PyOS_double_to_string` instead.
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