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# Integer Objects

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

`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`(PY_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 PY_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`(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`, 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 `'0o'` or `'0O'`, radix 8 will be used; if str starts with `'0b'` or `'0B'`, radix 2 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, `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()`.

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 *pylong)

  Return a C `long` representation of the contents of pylong. If pylong is greater than `LONG_MAX`, raise an `OverflowError`, and return -1. Convert non-long objects automatically to long first, and return -1 if that raises exceptions.

long `PyLong_AsLongAndOverflow`( PyObject *pylong, int* overflow)
  Return a C `long` representation of the contents of pylong. If pylong is greater than `LONG_MAX`, return -1 and set *overflow to 1 (for overflow) or -1 (for underflow). If an exception is set because of type errors, also return -1.

Py_ssize_t `PyLong_AsSsize_t`( PyObject *pylong)

  Return a C `Py_ssize_t` representation of the contents of pylong. If pylong is greater than `PY_SSIZE_T_MAX`, an `OverflowError` is raised and `-1` will be returned.

unsigned long `PyLong_AsUnsignedLong`( PyObject *pylong)

  Return a C `unsigned long` representation of the contents of pylong. If pylong is greater than `ULONG_MAX`, an `OverflowError` is raised.

size_t `PyLong_AsSize_t`( PyObject *pylong)
  Return a `size_t` representation of the contents of pylong. If pylong is greater than the maximum value for a `size_t`, an `OverflowError` is raised.

PY_LONG_LONG `PyLong_AsLongLong`( PyObject *pylong)

  Return a C `long long` from a Python integer. If pylong cannot be represented as a `long long`, an `OverflowError` is raised and `-1` is returned.

unsigned PY_LONG_LONG `PyLong_AsUnsignedLongLong`( PyObject *pylong)

  Return a C `unsigned long long` from a Python integer. If pylong cannot be represented as an `unsigned long long`, an `OverflowError` is raised and `(unsigned long long)-1` is returned.

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

unsigned long `PyLong_AsUnsignedLongMask`( PyObject *io)
  Return a C `unsigned long` from a Python integer, without checking for overflow.

unsigned PY_LONG_LONG `PyLong_AsUnsignedLongLongMask`( PyObject *io)
  Return a C `unsigned long long` from a Python integer, without checking for overflow.

double `PyLong_AsDouble`( PyObject *pylong)
  Return a C `double` representation of the contents of pylong. If pylong cannot be approximately represented as a `double`, an `OverflowError` exception is raised and `-1.0` will be returned.

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()`.

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