class ctypes.c_char Represents the C char datatype, and interprets the value as a single character. The constructor accepts an optional string initializer, the length of the string must be exactly one character.

class ctypes.c_byte Represents the C signed char datatype, and interprets the value as small integer. The constructor accepts an optional integer initializer; no overflow checking is done.

class ctypes.c_bool Represent the C bool datatype (more accurately, _Bool from C99). Its value can be True or False, and the constructor accepts any object that has a truth value.

ctypes.create_unicode_buffer(init_or_size, size=None) This function creates a mutable unicode character buffer. The returned object is a ctypes array of c_wchar. init_or_size must be an integer which specifies the size of the array, or a string which will be used to initialize the array items. If a string is specified as first argument, the buffer is made one item larger than the length of the string so that the last element in the array is a NUL termination character. An integer can be pass

ctypes.create_string_buffer(init_or_size, size=None) This function creates a mutable character buffer. The returned object is a ctypes array of c_char. init_or_size must be an integer which specifies the size of the array, or a bytes object which will be used to initialize the array items. If a bytes object is specified as first argument, the buffer is made one item larger than its length so that the last element in the array is a NUL termination character. An integer can be passed as second

ctypes.CFUNCTYPE(restype, *argtypes, use_errno=False, use_last_error=False) The returned function prototype creates functions that use the standard C calling convention. The function will release the GIL during the call. If use_errno is set to True, the ctypes private copy of the system errno variable is exchanged with the real errno value before and after the call; use_last_error does the same for the Windows error code.

class ctypes.CDLL(name, mode=DEFAULT_MODE, handle=None, use_errno=False, use_last_error=False) Instances of this class represent loaded shared libraries. Functions in these libraries use the standard C calling convention, and are assumed to return int.

ctypes.cast(obj, type) This function is similar to the cast operator in C. It returns a new instance of type which points to the same memory block as obj. type must be a pointer type, and obj must be an object that can be interpreted as a pointer.

ctypes.byref(obj[, offset]) Returns a light-weight pointer to obj, which must be an instance of a ctypes type. offset defaults to zero, and must be an integer that will be added to the internal pointer value. byref(obj, offset) corresponds to this C code: (((char *)&obj) + offset) The returned object can only be used as a foreign function call parameter. It behaves similar to pointer(obj), but the construction is a lot faster.

class ctypes.BigEndianStructure(*args, **kw) Abstract base class for structures in big endian byte order.