# Integer Objects¶

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 PyErr_Occurred() to disambiguate.

PyLongObject

This subtype of PyObject represents a Python integer object.

PyTypeObject PyLong_Type

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

int PyLong_Check(PyObject *p)

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

int PyLong_CheckExact(PyObject *p)

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

PyObject* PyLong_FromLong(long v)
Return value: New reference.

Return a new 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. :-)

PyObject* PyLong_FromUnsignedLong(unsigned long v)
Return value: New reference.

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

PyObject* PyLong_FromSsize_t(Py_ssize_t v)

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

PyObject* PyLong_FromSize_t(size_t v)

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

PyObject* PyLong_FromLongLong(long long v)
Return value: New reference.

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

PyObject* PyLong_FromUnsignedLongLong(unsigned long long v)
Return value: New reference.

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

PyObject* PyLong_FromDouble(double v)
Return value: New reference.

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

PyObject* PyLong_FromString(const char *str, char **pend, int base)
Return value: New reference.

Return a new 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 Integer literals definition; in this case, leading zeros in a non-zero decimal number raises a 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, ValueError will be raised.

PyObject* PyLong_FromUnicode(Py_UNICODE *u, Py_ssize_t length, int base)
Return value: New reference.

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

Deprecated since version 3.3, will be removed in version 4.0: Part of the old-style Py_UNICODE API; please migrate to using PyLong_FromUnicodeObject().

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 PyUnicode_EncodeDecimal() and then converted using PyLong_FromString().

New in version 3.3.

PyObject* PyLong_FromVoidPtr(void *p)
Return value: New reference.

Create a Python integer from the pointer p. The pointer value can be retrieved from the resulting value using PyLong_AsVoidPtr().

long PyLong_AsLong(PyObject *obj)

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

Raise OverflowError if the value of obj is out of range for a long.

Returns -1 on error. Use PyErr_Occurred() to disambiguate.

long PyLong_AsLongAndOverflow(PyObject *obj, int *overflow)

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

If the value of obj is greater than LONG_MAX or less than 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 PyErr_Occurred() to disambiguate.

long long PyLong_AsLongLong(PyObject *obj)

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

Raise OverflowError if the value of obj is out of range for a long.

Returns -1 on error. Use PyErr_Occurred() to disambiguate.

long long PyLong_AsLongLongAndOverflow(PyObject *obj, int *overflow)

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

If the value of obj is greater than PY_LLONG_MAX or less than 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 PyErr_Occurred() to disambiguate.

New in version 3.2.

Py_ssize_t PyLong_AsSsize_t(PyObject *pylong)

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

Raise OverflowError if the value of pylong is out of range for a Py_ssize_t.

Returns -1 on error. Use PyErr_Occurred() to disambiguate.

unsigned long PyLong_AsUnsignedLong(PyObject *pylong)

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

Raise OverflowError if the value of pylong is out of range for a unsigned long.

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

size_t PyLong_AsSize_t(PyObject *pylong)

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

Raise OverflowError if the value of pylong is out of range for a size_t.

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

unsigned long long PyLong_AsUnsignedLongLong(PyObject *pylong)

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

Raise OverflowError if the value of pylong is out of range for an unsigned long long.

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

Changed in version 3.1: A negative pylong now raises OverflowError, not TypeError.

unsigned long PyLong_AsUnsignedLongMask(PyObject *obj)

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

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

Returns -1 on error. Use PyErr_Occurred() to disambiguate.

unsigned long long PyLong_AsUnsignedLongLongMask(PyObject *obj)

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

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

Returns -1 on error. Use PyErr_Occurred() to disambiguate.

double PyLong_AsDouble(PyObject *pylong)

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

Raise OverflowError if the value of pylong is out of range for a double.

Returns -1.0 on error. Use PyErr_Occurred() to disambiguate.

void* PyLong_AsVoidPtr(PyObject *pylong)

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

Returns NULL on error. Use PyErr_Occurred() to disambiguate.