termios disappears during object deletion

[Fredrik Lundh]

Brien Barton <brien_barton at hotmail.com> wrote:
> Can anyone explain this behavior??  For some reason, the termios and TERMIOS
> modules get wiped out when python is running the __del__ method during
> program termination.  I've tried this with Python 1.5.1 on Linux and with
> Python 1.5.2 on SGI IRIX.  If you explicitly delete the object, you don't
> have this problem.
> 
> ~> cat test.py
> import math, termios, TERMIOS
> 
> print 'math=', math
> print 'termios=', termios
> print 'TERMIOS=', TERMIOS
> 
> class Test:
>     def __del__(self):
>         print 'deleting Test object ...'
>         print 'math=', math
>         print 'termios=', termios
>         print 'TERMIOS=', TERMIOS

starting with 1.5.1, Python performs a relatively aggressive
cleanup when the interpreter is shut down:

    http://www.python.org/doc/essays/cleanup.html

among other things, this means that destructors must hang
on to all global resources they are using, e.g.:

        def __del__(self, math=math, termios=termios, TERMIOS=TERMIOS):
            ...

</F>