Clarify acceptable values for BZ2File.__init__'s mode argument.
diff --git a/Doc/library/bz2.rst b/Doc/library/bz2.rst
index de5c825..893bb9b 100644
--- a/Doc/library/bz2.rst
+++ b/Doc/library/bz2.rst
@@ -35,9 +35,11 @@
be used to read or write the compressed data.
The *mode* argument can be either ``'r'`` for reading (default), ``'w'`` for
- overwriting, or ``'a'`` for appending. If *filename* is a file object (rather
- than an actual file name), a mode of ``'w'`` does not truncate the file, and
- is instead equivalent to ``'a'``.
+ overwriting, or ``'a'`` for appending. These can equivalently be given as
+ ``'rb'``, ``'wb'``, and ``'ab'`` respectively.
+
+ If *filename* is a file object (rather than an actual file name), a mode of
+ ``'w'`` does not truncate the file, and is instead equivalent to ``'a'``.
The *buffering* argument is ignored. Its use is deprecated.
diff --git a/Lib/bz2.py b/Lib/bz2.py
index ae59407..d04731b 100644
--- a/Lib/bz2.py
+++ b/Lib/bz2.py
@@ -46,8 +46,8 @@
be opened. Otherwise, it should be a file object, which will be used to
read or write the compressed data.
- mode can be 'r' for reading (default), 'w' for (over)writing, or
- 'a' for appending.
+ mode can be 'r' for reading (default), 'w' for (over)writing, or 'a' for
+ appending. These can equivalently be given as 'rb', 'wb', and 'ab'.
buffering is ignored. Its use is deprecated.