Issue #8603: Create a bytes version of os.environ for Unix

Create os.environb mapping and os.getenvb() function, os.unsetenv() encodes str
argument to the file system encoding with the surrogateescape error handler
(instead of utf8/strict) and accepts bytes, and posix.environ keys and values
are bytes.

1 files changed, 11 insertions, 6 deletions

diff --git a/Doc/library/posix.rst b/Doc/library/posix.rst
index c33d9e5..d65b999 100644
--- a/Doc/library/posix.rst
+++ b/Doc/library/posix.rst
@@ -69,17 +69,22 @@ In addition to many functions described in the :mod:`os` module documentation,
 .. data:: environ
 
    A dictionary representing the string environment at the time the interpreter
-   was started.  For example, ``environ['HOME']`` is the pathname of your home
-   directory, equivalent to ``getenv("HOME")`` in C.
+   was started. Keys and values are bytes on Unix and str on Windows. For
+   example, ``environ[b'HOME']`` (``environ['HOME']`` on Windows) is the
+   pathname of your home directory, equivalent to ``getenv("HOME")`` in C.
 
    Modifying this dictionary does not affect the string environment passed on by
    :func:`execv`, :func:`popen` or :func:`system`; if you need to change the
    environment, pass ``environ`` to :func:`execve` or add variable assignments and
    export statements to the command string for :func:`system` or :func:`popen`.
 
+   .. versionchanged:: 3.2
+      On Unix, keys and values are bytes.
+
    .. note::
 
-      The :mod:`os` module provides an alternate implementation of ``environ`` which
-      updates the environment on modification.  Note also that updating ``os.environ``
-      will render this dictionary obsolete.  Use of the :mod:`os` module version of
-      this is recommended over direct access to the :mod:`posix` module.
+      The :mod:`os` module provides an alternate implementation of ``environ``
+      which updates the environment on modification. Note also that updating
+      :data:`os.environ` will render this dictionary obsolete. Use of the
+      :mod:`os` module version of this is recommended over direct access to the
+      :mod:`posix` module.