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