Objetos Inteiros¶

Todos os inteiros são implementados como objetos inteiros “longos” de tamanho arbitrário.

Em caso de erro, a maioria das APIs PyLong_As* retorna (tipo de retorno)-1 que não pode ser distinguido de um número. Use PyErr_Occurred() para desambiguar.

type PyLongObject¶: Parte da API Limitada (como uma estrutura opaca).
Este subtipo de PyObject representa um objeto inteiro Python.

PyTypeObject PyLong_Type¶: Parte da ABI Estável.
Esta instância de PyTypeObject representa o tipo inteiro Python. Este é o mesmo objeto que int na camada Python.

int PyLong_Check(PyObject *p)¶: Retorna true se seu argumento é um PyLongObject ou um subtipo de PyLongObject. Esta função sempre tem sucesso.

int PyLong_CheckExact(PyObject *p)¶: Retorna true se seu argumento é um PyLongObject, mas não um subtipo de PyLongObject. Esta função sempre tem sucesso.

PyObject *PyLong_FromLong(long v)¶

Retorna valor: Nova referência. Parte da ABI Estável.

Retorna um novo objeto PyLongObject de v ou NULL em caso de falha.

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.

PyObject *PyLong_FromUnsignedLong(unsigned long v)¶: Retorna valor: Nova referência. Parte da ABI Estável.
Return a new PyLongObject object from a C unsigned long, or NULL on failure.

PyObject *PyLong_FromSsize_t(Py_ssize_t v)¶: Retorna valor: Nova referência. Parte da ABI Estável.
Retorna um novo objeto PyLongObject de um Py_ssize_t C ou NULL em caso de falha.

PyObject *PyLong_FromSize_t(size_t v)¶: Retorna valor: Nova referência. Parte da ABI Estável.
Retorna um novo objeto PyLongObject de um size_t C ou NULL em caso de falha.

PyObject *PyLong_FromLongLong(long long v)¶: Retorna valor: Nova referência. Parte da ABI Estável.
Return a new PyLongObject object from a C long long, or NULL on failure.

PyObject *PyLong_FromUnsignedLongLong(unsigned long long v)¶: Retorna valor: Nova referência. Parte da ABI Estável.
Return a new PyLongObject object from a C unsigned long long, or NULL on failure.

PyObject *PyLong_FromDouble(double v)¶: Retorna valor: Nova referência. Parte da ABI Estável.
Retorna um novo objeto PyLongObject da parte inteira de v ou NULL em caso de falha.

PyObject *PyLong_FromString(const char *str, char **pend, int base)¶: Retorna valor: Nova referência. Parte da ABI Estável.
Return a new PyLongObject based on the string value in str, which is interpreted according to the radix in base, or NULL on failure. If pend is non-NULL, *pend will point to the end of str on success or to the first character that could not be processed on error. If base is 0, str is interpreted using the Inteiros literais 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 and trailing whitespace and single underscores after a base specifier and between digits are ignored. If there are no digits or str is not NULL-terminated following the digits and trailing whitespace, ValueError will be raised.

Ver também

Python methods int.to_bytes() and int.from_bytes() to convert a PyLongObject to/from an array of bytes in base 256. You can call those from C using PyObject_CallMethod().

PyObject *PyLong_FromUnicodeObject(PyObject *u, int base)¶: Retorna valor: Nova referência.
Converte uma sequência de dígitos Unicode na string u para um valor inteiro Python.

Adicionado na versão 3.3.

PyObject *PyLong_FromVoidPtr(void *p)¶: Retorna valor: Nova referência. Parte da ABI Estável.
Cria um inteiro Python a partir do ponteiro p. O valor do ponteiro pode ser recuperado do valor resultante usando PyLong_AsVoidPtr().

PyObject *PyLong_FromNativeBytes(const void *buffer, size_t n_bytes, int flags)¶

Create a Python integer from the value contained in the first n_bytes of buffer, interpreted as a two’s-complement signed number.

flags are as for PyLong_AsNativeBytes(). Passing -1 will select the native endian that CPython was compiled with and assume that the most-significant bit is a sign bit. Passing Py_ASNATIVEBYTES_UNSIGNED_BUFFER will produce the same result as calling PyLong_FromUnsignedNativeBytes(). Other flags are ignored.

Adicionado na versão 3.13.

PyObject *PyLong_FromUnsignedNativeBytes(const void *buffer, size_t n_bytes, int flags)¶

Create a Python integer from the value contained in the first n_bytes of buffer, interpreted as an unsigned number.

flags are as for PyLong_AsNativeBytes(). Passing -1 will select the native endian that CPython was compiled with and assume that the most-significant bit is not a sign bit. Flags other than endian are ignored.

Adicionado na versão 3.13.

long PyLong_AsLong(PyObject *obj)¶

Parte da ABI Estável.

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

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

Retorna -1 no caso de erro. Use PyErr_Occurred() para desambiguar.

Alterado na versão 3.8: Usa __index__(), se disponível.

Alterado na versão 3.10: This function will no longer use __int__().

int PyLong_AsInt(PyObject *obj)¶: Parte da ABI Estável desde a versão 3.13.
Similar to PyLong_AsLong(), but store the result in a C int instead of a C long.

Adicionado na versão 3.13.

long PyLong_AsLongAndOverflow(PyObject *obj, int *overflow)¶

Parte da ABI Estável.

Return a C long representation of obj. If obj is not an instance of PyLongObject, first call its __index__() 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.

Retorna -1 no caso de erro. Use PyErr_Occurred() para desambiguar.

Alterado na versão 3.8: Usa __index__(), se disponível.

Alterado na versão 3.10: This function will no longer use __int__().

long long PyLong_AsLongLong(PyObject *obj)¶

Parte da ABI Estável.

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

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

Retorna -1 no caso de erro. Use PyErr_Occurred() para desambiguar.

Alterado na versão 3.8: Usa __index__(), se disponível.

Alterado na versão 3.10: This function will no longer use __int__().

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

Parte da ABI Estável.

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

If the value of obj is greater than LLONG_MAX or less than 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.

Retorna -1 no caso de erro. Use PyErr_Occurred() para desambiguar.

Adicionado na versão 3.2.

Alterado na versão 3.8: Usa __index__(), se disponível.

Alterado na versão 3.10: This function will no longer use __int__().

Py_ssize_t PyLong_AsSsize_t(PyObject *pylong)¶

Parte da ABI Estável.

Retorna uma representação de Py_ssize_t C de pylong. pylong deve ser uma instância de PyLongObject.

Levanta OverflowError se o valor de pylong estiver fora do intervalo de um Py_ssize_t.

Retorna -1 no caso de erro. Use PyErr_Occurred() para desambiguar.

unsigned long PyLong_AsUnsignedLong(PyObject *pylong)¶

Parte da ABI Estável.

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.

Retorna (unsigned long)-1 no caso de erro. Use PyErr_Occurred() para desambiguar.

size_t PyLong_AsSize_t(PyObject *pylong)¶

Parte da ABI Estável.

Retorna uma representação de size_t C de pylong. pylong deve ser uma instância de PyLongObject.

Levanta OverflowError se o valor de pylong estiver fora do intervalo de um size_t.

Retorna (size)-1 no caso de erro. Use PyErr_Occurred() para desambiguar.

unsigned long long PyLong_AsUnsignedLongLong(PyObject *pylong)¶

Parte da ABI Estável.

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.

Retorna (unsigned long long)-1 no caso de erro. Use PyErr_Occurred() para desambiguar.

Alterado na versão 3.1: Um pylong negativo agora levanta OverflowError, não TypeError.

unsigned long PyLong_AsUnsignedLongMask(PyObject *obj)¶

Parte da ABI Estável.

Return a C unsigned long representation of obj. If obj is not an instance of PyLongObject, first call its __index__() 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.

Retorna (unsigned long)-1 no caso de erro. Use PyErr_Occurred() para desambiguar.

Alterado na versão 3.8: Usa __index__(), se disponível.

Alterado na versão 3.10: This function will no longer use __int__().

unsigned long long PyLong_AsUnsignedLongLongMask(PyObject *obj)¶

Parte da ABI Estável.

Return a C unsigned long long representation of obj. If obj is not an instance of PyLongObject, first call its __index__() 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 ULLONG_MAX + 1.

Retorna (unsigned long long)-1 no caso de erro. Use PyErr_Occurred() para desambiguar.

Alterado na versão 3.8: Usa __index__(), se disponível.

Alterado na versão 3.10: This function will no longer use __int__().

double PyLong_AsDouble(PyObject *pylong)¶

Parte da ABI Estável.

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.

Retorna -1.0 no caso de erro. Use PyErr_Occurred() para desambiguar.

void *PyLong_AsVoidPtr(PyObject *pylong)¶

Parte da ABI Estável.

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().

Retorna NULL no caso de erro. Use PyErr_Occurred() para desambiguar.

Py_ssize_t PyLong_AsNativeBytes(PyObject *pylong, void *buffer, Py_ssize_t n_bytes, int flags)¶

Copy the Python integer value pylong to a native buffer of size n_bytes. The flags can be set to -1 to behave similarly to a C cast, or to values documented below to control the behavior.

Returns -1 with an exception raised on error. This may happen if pylong cannot be interpreted as an integer, or if pylong was negative and the Py_ASNATIVEBYTES_REJECT_NEGATIVE flag was set.

Otherwise, returns the number of bytes required to store the value. If this is equal to or less than n_bytes, the entire value was copied. All n_bytes of the buffer are written: large buffers are padded with zeroes.

If the returned value is greater than than n_bytes, the value was truncated: as many of the lowest bits of the value as could fit are written, and the higher bits are ignored. This matches the typical behavior of a C-style downcast.

Nota

Overflow is not considered an error. If the returned value is larger than n_bytes, most significant bits were discarded.

0 will never be returned.

Values are always copied as two’s-complement.

Usage example:

int32_t value;
Py_ssize_t bytes = PyLong_AsNativeBits(pylong, &value, sizeof(value), -1);
if (bytes < 0) {
    // Failed. A Python exception was set with the reason.
    return NULL;
}
else if (bytes <= (Py_ssize_t)sizeof(value)) {
    // Success!
}
else {
    // Overflow occurred, but 'value' contains the truncated
    // lowest bits of pylong.
}

Passing zero to n_bytes will return the size of a buffer that would be large enough to hold the value. This may be larger than technically necessary, but not unreasonably so.

Nota

Passing n_bytes=0 to this function is not an accurate way to determine the bit length of a value.

If n_bytes=0, buffer may be NULL.

To get at the entire Python value of an unknown size, the function can be called twice: first to determine the buffer size, then to fill it:

// Ask how much space we need.
Py_ssize_t expected = PyLong_AsNativeBits(pylong, NULL, 0, -1);
if (expected < 0) {
    // Failed. A Python exception was set with the reason.
    return NULL;
}
assert(expected != 0);  // Impossible per the API definition.
uint8_t *bignum = malloc(expected);
if (!bignum) {
    PyErr_SetString(PyExc_MemoryError, "bignum malloc failed.");
    return NULL;
}
// Safely get the entire value.
Py_ssize_t bytes = PyLong_AsNativeBits(pylong, bignum, expected, -1);
if (bytes < 0) {  // Exception has been set.
    free(bignum);
    return NULL;
}
else if (bytes > expected) {  // This should not be possible.
    PyErr_SetString(PyExc_RuntimeError,
        "Unexpected bignum truncation after a size check.");
    free(bignum);
    return NULL;
}
// The expected success given the above pre-check.
// ... use bignum ...
free(bignum);

flags is either -1 (Py_ASNATIVEBYTES_DEFAULTS) to select defaults that behave most like a C cast, or a combintation of the other flags in the table below. Note that -1 cannot be combined with other flags.

Currently, -1 corresponds to Py_ASNATIVEBYTES_NATIVE_ENDIAN | Py_ASNATIVEBYTES_UNSIGNED_BUFFER.

Flag	Value
Py_ASNATIVEBYTES_DEFAULTS¶	`-1`
Py_ASNATIVEBYTES_BIG_ENDIAN¶	`0`
Py_ASNATIVEBYTES_LITTLE_ENDIAN¶	`1`
Py_ASNATIVEBYTES_NATIVE_ENDIAN¶	`3`
Py_ASNATIVEBYTES_UNSIGNED_BUFFER¶	`4`
Py_ASNATIVEBYTES_REJECT_NEGATIVE¶	`8`

Specifying Py_ASNATIVEBYTES_NATIVE_ENDIAN will override any other endian flags. Passing 2 is reserved.

By default, sufficient buffer will be requested to include a sign bit. For example, when converting 128 with n_bytes=1, the function will return 2 (or more) in order to store a zero sign bit.

If Py_ASNATIVEBYTES_UNSIGNED_BUFFER is specified, a zero sign bit will be omitted from size calculations. This allows, for example, 128 to fit in a single-byte buffer. If the destination buffer is later treated as signed, a positive input value may become negative. Note that the flag does not affect handling of negative values: for those, space for a sign bit is always requested.

Specifying Py_ASNATIVEBYTES_REJECT_NEGATIVE causes an exception to be set if pylong is negative. Without this flag, negative values will be copied provided there is enough space for at least one sign bit, regardless of whether Py_ASNATIVEBYTES_UNSIGNED_BUFFER was specified.

Nota

With the default flags (-1, or UNSIGNED_BUFFER without REJECT_NEGATIVE), multiple Python integers can map to a single value without overflow. For example, both 255 and -1 fit a single-byte buffer and set all its bits. This matches typical C cast behavior.

Adicionado na versão 3.13.

int PyUnstable_Long_IsCompact(const PyLongObject *op)¶

Esta é uma API Instável. Isso pode se alterado sem aviso em lançamentos menores.

Return 1 if op is compact, 0 otherwise.

This function makes it possible for performance-critical code to implement a “fast path” for small integers. For compact values use PyUnstable_Long_CompactValue(); for others fall back to a PyLong_As* function or PyLong_AsNativeBytes().

The speedup is expected to be negligible for most users.

Exactly what values are considered compact is an implementation detail and is subject to change.

Py_ssize_t PyUnstable_Long_CompactValue(const PyLongObject *op)¶

Esta é uma API Instável. Isso pode se alterado sem aviso em lançamentos menores.

If op is compact, as determined by PyUnstable_Long_IsCompact(), return its value.

Otherwise, the return value is undefined.

Objetos Inteiros¶

Tópico anterior

Próximo tópico

Esta página