Support for SEEK_HOLE/SEEK_DATA

Doc/library/os.rst

 :mod:`os` --- Miscellaneous operating system interfaces
 =======================================================
 
 .. module:: os
    :synopsis: Miscellaneous operating system interfaces.
 
 
 This module provides a portable way of using operating system dependent
 functionality.  If you just want to read or write a file see :func:`open`, if
 you want to manipulate paths, see the :mod:`os.path` module, and if you want to
@@ skipping 973 matching lines @@
 
    Availability: Unix, Windows.
 
 
 .. data:: SEEK_SET
           SEEK_CUR
           SEEK_END
 
    Parameters to the :func:`lseek` function. Their values are 0, 1, and 2,
    respectively. Availability: Windows, Unix.
+
+   .. versionadded:: 3.3
+      Some operating systems could support additional values, like
+      :data:`os.SEEK_HOLE` or :data:`os.SEEK_DATA`.
 
 
 .. function:: mkdirat(dirfd, path, mode=0o777)
 
    Like :func:`mkdir` but if *path* is relative, it is taken as relative to *dirfd*.
    If *path* is relative and *dirfd* is the special value :data:`AT_FDCWD`, then *path*
    is interpreted relative to the current working directory.
 
    Availability: Unix.
 
@@ skipping 2315 matching lines @@
 
 .. function:: urandom(n)
 
    Return a string of *n* random bytes suitable for cryptographic use.
 
    This function returns random bytes from an OS-specific randomness source.  The
    returned data should be unpredictable enough for cryptographic applications,
    though its exact quality depends on the OS implementation.  On a UNIX-like
    system this will query /dev/urandom, and on Windows it will use CryptGenRandom.
    If a randomness source is not found, :exc:`NotImplementedError` will be raised.