Integer Objects

.. highlightlang:: c

.. _longobjects:

Integer Objects

.. index:: object: long integer object: integer

All integers are implemented as "long" integer objects of arbitrary size.

On error, most PyLong_As* APIs return (return type)-1 which cannot be distinguished from a number. Use :c:func:PyErr_Occurred to disambiguate.

.. c:type:: PyLongObject

This subtype of :c:type:PyObject represents a Python integer object.

.. c:var:: PyTypeObject PyLong_Type

This instance of :c:type:PyTypeObject represents the Python integer type. This is the same object as :class:int in the Python layer.

.. c:function:: int PyLong_Check(PyObject *p)

Return true if its argument is a :c:type:PyLongObject or a subtype of :c:type:PyLongObject.

.. c:function:: int PyLong_CheckExact(PyObject *p)

Return true if its argument is a :c:type:PyLongObject, but not a subtype of :c:type:PyLongObject.

.. c:function:: PyObject* PyLong_FromLong(long v)

Return a new :c:type:PyLongObject object from v, or NULL on failure.

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. :-)

.. c:function:: PyObject* PyLong_FromUnsignedLong(unsigned long v)

Return a new :c:type:PyLongObject object from a C :c:type:unsigned long, or NULL on failure.

.. c:function:: PyObject* PyLong_FromSsize_t(Py_ssize_t v)

Return a new :c:type:PyLongObject object from a C :c:type:Py_ssize_t, or NULL on failure.

.. c:function:: PyObject* PyLong_FromSize_t(size_t v)

Return a new :c:type:PyLongObject object from a C :c:type:size_t, or NULL on failure.

.. c:function:: PyObject* PyLong_FromLongLong(long long v)

Return a new :c:type:PyLongObject object from a C :c:type:long long, or NULL on failure.

.. c:function:: PyObject* PyLong_FromUnsignedLongLong(unsigned long long v)

Return a new :c:type:PyLongObject object from a C :c:type:unsigned long long, or NULL on failure.

.. c:function:: PyObject* PyLong_FromDouble(double v)

Return a new :c:type:PyLongObject object from the integer part of v, or NULL on failure.

.. c:function:: PyObject* PyLong_FromString(const char *str, char **pend, int base)

Return a new :c:type: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, str is interpreted using the :ref:integers definition; in this case, leading zeros in a non-zero decimal number raises a :exc:ValueError. If base is not 0, it must be between 2 and 36, inclusive. Leading spaces and single underscores after a base specifier and between digits are ignored. If there are no digits, :exc:ValueError will be raised.

.. c:function:: PyObject* PyLong_FromUnicode(Py_UNICODE *u, Py_ssize_t length, int base)

Convert a sequence of Unicode digits to a Python integer value. The Unicode string is first encoded to a byte string using :c:func:PyUnicode_EncodeDecimal and then converted using :c:func:PyLong_FromString.

.. deprecated-removed:: 3.3 4.0 Part of the old-style :c:type:Py_UNICODE API; please migrate to using :c:func:PyLong_FromUnicodeObject.

.. c:function:: PyObject* PyLong_FromUnicodeObject(PyObject *u, int base)

Convert a sequence of Unicode digits in the string u to a Python integer value. The Unicode string is first encoded to a byte string using :c:func:PyUnicode_EncodeDecimal and then converted using :c:func:PyLong_FromString.

.. versionadded:: 3.3

.. c:function:: PyObject* PyLong_FromVoidPtr(void *p)

Create a Python integer from the pointer p. The pointer value can be retrieved from the resulting value using :c:func:PyLong_AsVoidPtr.

.. XXX alias PyLong_AS_LONG (for now) .. c:function:: long PyLong_AsLong(PyObject *obj)

.. index:: single: LONG_MAX single: OverflowError (built-in exception)

Return a C :c:type:long representation of obj. If obj is not an instance of :c:type:PyLongObject, first call its :meth:__int__ method (if present) to convert it to a :c:type:PyLongObject.

Raise :exc:OverflowError if the value of obj is out of range for a :c:type:long.

Returns -1 on error. Use :c:func:PyErr_Occurred to disambiguate.

.. c:function:: long PyLong_AsLongAndOverflow(PyObject *obj, int *overflow)

Return a C :c:type:long representation of obj. If obj is not an instance of :c:type:PyLongObject, first call its :meth:__int__ method (if present) to convert it to a :c:type:PyLongObject.

If the value of obj is greater than :const:LONG_MAX or less than :const:LONG_MIN, set *overflow to 1 or -1, respectively, and return -1; otherwise, set *overflow to 0. If any other exception occurs set *overflow to 0 and return -1 as usual.

Returns -1 on error. Use :c:func:PyErr_Occurred to disambiguate.

.. c:function:: long long PyLong_AsLongLong(PyObject *obj)

.. index:: single: OverflowError (built-in exception)

Return a C :c:type:long long representation of obj. If obj is not an instance of :c:type:PyLongObject, first call its :meth:__int__ method (if present) to convert it to a :c:type:PyLongObject.

Raise :exc:OverflowError if the value of obj is out of range for a :c:type:long.

Returns -1 on error. Use :c:func:PyErr_Occurred to disambiguate.

.. c:function:: long long PyLong_AsLongLongAndOverflow(PyObject *obj, int *overflow)

Return a C :c:type:long long representation of obj. If obj is not an instance of :c:type:PyLongObject, first call its :meth:__int__ method (if present) to convert it to a :c:type:PyLongObject.

If the value of obj is greater than :const:PY_LLONG_MAX or less than :const:PY_LLONG_MIN, set *overflow to 1 or -1, respectively, and return -1; otherwise, set *overflow to 0. If any other exception occurs set *overflow to 0 and return -1 as usual.

Returns -1 on error. Use :c:func:PyErr_Occurred to disambiguate.

.. versionadded:: 3.2

.. c:function:: Py_ssize_t PyLong_AsSsize_t(PyObject *pylong)

.. index:: single: PY_SSIZE_T_MAX single: OverflowError (built-in exception)

Return a C :c:type:Py_ssize_t representation of pylong. pylong must be an instance of :c:type:PyLongObject.

Raise :exc:OverflowError if the value of pylong is out of range for a :c:type:Py_ssize_t.

Returns -1 on error. Use :c:func:PyErr_Occurred to disambiguate.

.. c:function:: unsigned long PyLong_AsUnsignedLong(PyObject *pylong)

.. index:: single: ULONG_MAX single: OverflowError (built-in exception)

Return a C :c:type:unsigned long representation of pylong. pylong must be an instance of :c:type:PyLongObject.

Raise :exc:OverflowError if the value of pylong is out of range for a :c:type:unsigned long.

Returns (unsigned long)-1 on error. Use :c:func:PyErr_Occurred to disambiguate.

.. c:function:: size_t PyLong_AsSize_t(PyObject *pylong)

.. index:: single: SIZE_MAX single: OverflowError (built-in exception)

Return a C :c:type:size_t representation of pylong. pylong must be an instance of :c:type:PyLongObject.

Raise :exc:OverflowError if the value of pylong is out of range for a :c:type:size_t.

Returns (size_t)-1 on error. Use :c:func:PyErr_Occurred to disambiguate.

.. c:function:: unsigned long long PyLong_AsUnsignedLongLong(PyObject *pylong)

.. index:: single: OverflowError (built-in exception)

Return a C :c:type:unsigned long long representation of pylong. pylong must be an instance of :c:type:PyLongObject.

Raise :exc:OverflowError if the value of pylong is out of range for an :c:type:unsigned long long.

Returns (unsigned long long)-1 on error. Use :c:func:PyErr_Occurred to disambiguate.

.. versionchanged:: 3.1 A negative pylong now raises :exc:OverflowError, not :exc:TypeError.

.. c:function:: unsigned long PyLong_AsUnsignedLongMask(PyObject *obj)

Return a C :c:type:unsigned long representation of obj. If obj is not an instance of :c:type:PyLongObject, first call its :meth:__int__ method (if present) to convert it to a :c:type:PyLongObject.

If the value of obj is out of range for an :c:type:unsigned long, return the reduction of that value modulo ULONG_MAX + 1.

Returns -1 on error. Use :c:func:PyErr_Occurred to disambiguate.

.. c:function:: unsigned long long PyLong_AsUnsignedLongLongMask(PyObject *obj)

Return a C :c:type:unsigned long long representation of obj. If obj is not an instance of :c:type:PyLongObject, first call its :meth:__int__ method (if present) to convert it to a :c:type:PyLongObject.

If the value of obj is out of range for an :c:type:unsigned long long, return the reduction of that value modulo PY_ULLONG_MAX + 1.

Returns -1 on error. Use :c:func:PyErr_Occurred to disambiguate.

.. c:function:: double PyLong_AsDouble(PyObject *pylong)

Return a C :c:type:double representation of pylong. pylong must be an instance of :c:type:PyLongObject.

Raise :exc:OverflowError if the value of pylong is out of range for a :c:type:double.

Returns -1.0 on error. Use :c:func:PyErr_Occurred to disambiguate.

.. c:function:: void* PyLong_AsVoidPtr(PyObject *pylong)

Convert a Python integer pylong to a C :c:type:void pointer. If pylong cannot be converted, an :exc:OverflowError will be raised. This is only assured to produce a usable :c:type:void pointer for values created with :c:func:PyLong_FromVoidPtr.

Returns NULL on error. Use :c:func:PyErr_Occurred to disambiguate.