cpython/Doc/c-api/int.rst

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.. highlightlang:: c
.. _intobjects:
Plain Integer Objects
---------------------
.. index:: object: integer
.. ctype:: PyIntObject
This subtype of :ctype:`PyObject` represents a Python integer object.
.. cvar:: PyTypeObject PyInt_Type
.. index:: single: IntType (in modules types)
This instance of :ctype:`PyTypeObject` represents the Python plain integer type.
This is the same object as ``int`` and ``types.IntType``.
.. cfunction:: int PyInt_Check(PyObject *o)
Return true if *o* is of type :cdata:`PyInt_Type` or a subtype of
:cdata:`PyInt_Type`.
.. versionchanged:: 2.2
Allowed subtypes to be accepted.
.. cfunction:: int PyInt_CheckExact(PyObject *o)
Return true if *o* is of type :cdata:`PyInt_Type`, but not a subtype of
:cdata:`PyInt_Type`.
.. versionadded:: 2.2
.. cfunction:: PyObject* PyInt_FromString(char *str, char **pend, int base)
Return a new :ctype:`PyIntObject` or :ctype:`PyLongObject` based on the string
value in *str*, which is interpreted according to the radix in *base*. If
*pend* is non-*NULL*, ``*pend`` will point to the first character in *str* which
follows the representation of the number. If *base* is ``0``, the radix will be
determined based on the leading characters of *str*: if *str* starts with
``'0x'`` or ``'0X'``, radix 16 will be used; if *str* starts with ``'0'``, radix
8 will be used; otherwise radix 10 will be used. If *base* is not ``0``, it
must be between ``2`` and ``36``, inclusive. Leading spaces are ignored. If
there are no digits, :exc:`ValueError` will be raised. If the string represents
a number too large to be contained within the machine's :ctype:`long int` type
and overflow warnings are being suppressed, a :ctype:`PyLongObject` will be
returned. If overflow warnings are not being suppressed, *NULL* will be
returned in this case.
.. cfunction:: PyObject* PyInt_FromLong(long ival)
Create a new integer object with a value of *ival*.
The current implementation keeps an array of integer objects for all integers
between ``-5`` and ``256``, when you create an int in that range you actually
just get back a reference to the existing object. So it should be possible to
change the value of ``1``. I suspect the behaviour of Python in this case is
undefined. :-)
.. cfunction:: PyObject* PyInt_FromSsize_t(Py_ssize_t ival)
Create a new integer object with a value of *ival*. If the value is larger
than ``LONG_MAX`` or smaller than ``LONG_MIN``, a long integer object is
returned.
.. versionadded:: 2.5
.. cfunction:: PyObject* PyInt_FromSize_t(size_t ival)
Create a new integer object with a value of *ival*. If the value exceeds
``LONG_MAX``, a long integer object is returned.
.. versionadded:: 2.5
.. cfunction:: long PyInt_AsLong(PyObject *io)
Will first attempt to cast the object to a :ctype:`PyIntObject`, if it is not
already one, and then return its value. If there is an error, ``-1`` is
returned, and the caller should check ``PyErr_Occurred()`` to find out whether
there was an error, or whether the value just happened to be -1.
.. cfunction:: long PyInt_AS_LONG(PyObject *io)
Return the value of the object *io*. No error checking is performed.
.. cfunction:: unsigned long PyInt_AsUnsignedLongMask(PyObject *io)
Will first attempt to cast the object to a :ctype:`PyIntObject` or
:ctype:`PyLongObject`, if it is not already one, and then return its value as
unsigned long. This function does not check for overflow.
.. versionadded:: 2.3
.. cfunction:: unsigned PY_LONG_LONG PyInt_AsUnsignedLongLongMask(PyObject *io)
Will first attempt to cast the object to a :ctype:`PyIntObject` or
:ctype:`PyLongObject`, if it is not already one, and then return its value as
unsigned long long, without checking for overflow.
.. versionadded:: 2.3
.. cfunction:: Py_ssize_t PyInt_AsSsize_t(PyObject *io)
Will first attempt to cast the object to a :ctype:`PyIntObject` or
:ctype:`PyLongObject`, if it is not already one, and then return its value as
:ctype:`Py_ssize_t`.
.. versionadded:: 2.5
.. cfunction:: long PyInt_GetMax()
.. index:: single: LONG_MAX
Return the system's idea of the largest integer it can handle
(:const:`LONG_MAX`, as defined in the system header files).
.. cfunction:: int PyInt_ClearFreeList()
Clear the integer free list. Return the number of items that could not
be freed.
.. versionadded:: 2.6