parse an environment file

[Jason Friedman]

> I want my python 3.2.2 script, called via cron, to know what those
> additional variables are.  How?

Thank you for the feedback.  A crontab line of

* * * * * . /path/to/export_file && /path/to/script.py

does indeed work, but for various reasons this approach will not
always be available to me.

Let me restate my question.  I have a file that looks like this:
export VAR1=foo
export VAR2=bar
# Comment
export VAR3=${VAR1}${VAR2}

I want this:
my_dict = {'VAR1': 'foo', 'VAR2': 'bar', 'VAR3': 'foobar'}

I can roll my own, but I'm thinking there is a module or existing code
that does this.  I looked at the os and sys and configparse modules
but did not see it.