Bytes Objects

These functions raise TypeError when expecting a bytes parameter and called with a non-bytes parameter.

type PyBytesObject

This subtype of PyObject represents a Python bytes object.

PyTypeObject PyBytes_Type

Part of the Stable ABI.

This instance of PyTypeObject represents the Python bytes type; it is the same object as bytes in the Python layer.

int PyBytes_Check(PyObject *o)

Return true if the object o is a bytes object or an instance of a subtype of the bytes type. This function always succeeds.

int PyBytes_CheckExact(PyObject *o)

Return true if the object o is a bytes object, but not an instance of a subtype of the bytes type. This function always succeeds.

PyObject *PyBytes_FromString(const char *v)

Return value: New reference. Part of the Stable ABI. Thread safety: Atomic.

Return a new bytes object with a copy of the string v as value on success, and NULL on failure. The parameter v must not be NULL; it will not be checked.

PyObject *PyBytes_FromStringAndSize(const char *v, Py_ssize_t len)

Return value: New reference. Part of the Stable ABI. Thread safety: Atomic.

Return a new bytes object with a copy of the string v as value and length len on success, and NULL on failure. If v is NULL, the contents of the bytes object are uninitialized.

PyObject *PyBytes_FromFormat(const char *format, ...)

Return value: New reference. Part of the Stable ABI. Thread safety: Atomic.

Take a C printf()-style format string and a variable number of arguments, calculate the size of the resulting Python bytes object and return a bytes object with the values formatted into it. The variable arguments must be C types and must correspond exactly to the format characters in the format string. The following format characters are allowed:

Format Characters	Type	Comment
%%	n/a	The literal % character.
%c	int	A single byte, represented as a C int.
%d	int	Equivalent to printf("%d"). [1]
%u	unsigned int	Equivalent to printf("%u"). [1]
%ld	long	Equivalent to printf("%ld"). [1]
%lu	unsigned long	Equivalent to printf("%lu"). [1]
%zd	Py_ssize_t	Equivalent to printf("%zd"). [1]
%zu	size_t	Equivalent to printf("%zu"). [1]
%i	int	Equivalent to printf("%i"). [1]
%x	int	Equivalent to printf("%x"). [1]
%s	const char*	A null-terminated C character array.
%p	const void*	The hex representation of a C pointer. Mostly equivalent to printf("%p") except that it is guaranteed to start with the literal 0x regardless of what the platform’s printf yields.

An unrecognized format character causes all the rest of the format string to be copied as-is to the result object, and any extra arguments discarded.

[1] (1,2,3,4,5,6,7,8)

For integer specifiers (d, u, ld, lu, zd, zu, i, x): the 0-conversion flag has effect even when a precision is given.

PyObject *PyBytes_FromFormatV(const char *format, va_list vargs)

Return value: New reference. Part of the Stable ABI. Thread safety: Atomic.

Identical to PyBytes_FromFormat() except that it takes exactly two arguments.

PyObject *PyBytes_FromObject(PyObject *o)

Return value: New reference. Part of the Stable ABI. Thread safety: Safe for concurrent use on the same object.

Return the bytes representation of object o that implements the buffer protocol.

Note

If the object implements the buffer protocol, then the buffer must not be mutated while the bytes object is being created.

Py_ssize_t PyBytes_Size(PyObject *o)

Part of the Stable ABI. Thread safety: Atomic.

Return the length of the bytes in bytes object o.

Py_ssize_t PyBytes_GET_SIZE(PyObject *o)

Thread safety: Atomic.

Similar to PyBytes_Size(), but without error checking.

char *PyBytes_AsString(PyObject *o)

Part of the Stable ABI. Thread safety: Safe to call from multiple threads with external synchronization only.

Return a pointer to the contents of o. The pointer refers to the internal buffer of o, which consists of len(o) + 1 bytes. The last byte in the buffer is always null, regardless of whether there are any other null bytes. The data must not be modified in any way, unless the object was just created using PyBytes_FromStringAndSize(NULL, size). It must not be deallocated. If o is not a bytes object at all, PyBytes_AsString() returns NULL and raises TypeError.

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