Newbie question - calling external Python programs

[jepler epler]

On Sat, 19 Aug 2000 22:21:16 GMT, Stephen Ferg
 <stephen_ferg at worldnet.att.net> wrote:
>My name is Steve Ferg.  I am a newbie convert to Python from Rexx.  I want
>to port a big Rexx application to Python, and I need some guidance on Python
>design philosophy for moderately large applications.

While the code is probably not the easiest to understand, I seem to recall
that PMW (Python Megawidgets for Tk) provides a way to defer mdoule loading
until it is needed.  You might want to take a look at this code and evalute
whether you can re-use it to get the results you want.

Also, you could try code like the following:

class LazyImporter:
	def __getattr__(self, item):
		self.__dict__[item] = __import__(item)
		return self.__dict__[item]

	>>> l = LazyImporter
	>>> dir(l)
	[]
	>>> l.sys.stdin
	<open file '<stdin>', mode 'r' at 80a0f50>
	>>> dir(l)
	['sys']

A provision to unload a module is more difficult.  Even if you delete a key
from l's dict, the module remains in sys.modules.  It seems to me that if you
	>>> del l.somemodule
	>>> del sys.modules['somemodule']
	>>> l.somemodule
but somebody has stored a reference to somemodule, you will end up with two
copies of it, which is not desirable.

Jeff