# Byte Array Objects

type PyByteArrayObject

  This subtype of `PyObject` represents a Python bytearray object.

PyTypeObject PyByteArray_Type
  Part of the Stable ABI.

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

## Type check macros

int PyByteArray_Check(PyObject *o)

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

int PyByteArray_CheckExact(PyObject *o)

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

## Direct API functions

PyObject *PyByteArray_FromObject(PyObject *o)
  Return value: New reference. Part of the Stable ABI. Thread safety: Safe for concurrent use on the same object.

  Return a new bytearray object from any object, o, that implements the buffer protocol.

  On failure, return `NULL` with an exception set.

  Note

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

PyObject *PyByteArray_FromStringAndSize(const char *string, Py_ssize_t len)
  Return value: New reference. Part of the Stable ABI. Thread safety: Atomic.

  Create a new bytearray object from string and its length, len.

  On failure, return `NULL` with an exception set.

PyObject *PyByteArray_Concat(PyObject *a, PyObject *b)
  Return value: New reference. Part of the Stable ABI. Thread safety: Safe for concurrent use on the same object.

  Concat bytearrays a and b and return a new bytearray with the result.

  On failure, return `NULL` with an exception set.

  Note

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

Py_ssize_t PyByteArray_Size(PyObject *bytearray)
  Part of the Stable ABI. Thread safety: Atomic.

  Return the size of bytearray after checking for a `NULL` pointer.

char *PyByteArray_AsString(PyObject *bytearray)
  Part of the Stable ABI. Thread safety: Safe to call from multiple threads with external synchronization only.

  Return the contents of bytearray as a char array after checking for a `NULL` pointer. The returned array always has an extra null byte appended.

  Note

  It is not thread-safe to mutate the bytearray object while using the returned char array.

int PyByteArray_Resize(PyObject *bytearray, Py_ssize_t len)
  Part of the Stable ABI.

  Resize the internal buffer of bytearray to len. Failure is a `-1` return with an exception set.

  Changed in version 3.14: A negative len will now result in an exception being set and -1 returned.

## Macros

These macros trade safety for speed and they don’t check pointers.

char *PyByteArray_AS_STRING(PyObject *bytearray)
  Thread safety: Safe to call from multiple threads with external synchronization only.

  Similar to `PyByteArray_AsString()`, but without error checking.

  Note

  It is not thread-safe to mutate the bytearray object while using the returned char array.

Py_ssize_t PyByteArray_GET_SIZE(PyObject *bytearray)
  Thread safety: Atomic.

  Similar to `PyByteArray_Size()`, but without error checking.