On Sun, Dec 30, 2012 at 8:39 AM, nick.coghlan <python-checkins@python.org> wrote:
[SNIP]
 The ``-E`` command line option allows all environment variables to be
-ignored when initialising the Python interpreter. An embedding application
+ignored when initializing the Python interpreter. An embedding application
 can enable this behaviour by setting ``Py_IgnoreEnvironmentFlag`` before
 calling ``Py_Initialize()``.

 In the CPython source code, the ``Py_GETENV`` macro implicitly checks this
 flag, and always produces ``NULL`` if it is set.

+<TBD: I believe PYTHONCASEOK is checked regardless of this setting >
 <TBD: Does -E also ignore Windows registry keys? >


That is true and that is a bug. =)

http://bugs.python.org/issue16826