Scientific plotting calls for Python on Mac??

[Louis M. Pecora]

There seem to be several packages out there for Python
scientific/numeric plotting on the Mac, but it is not clear which are
simplest to use -- my criteria.  Some seem to require several packages. 
Although I will pursue trying to sort this out, let me ask:

Does anyone know of a simple, "standalone" Python plotting module?

Even just, open a window, draw some lines and simple patterns, write a
little text, maybe even catch some keystroke events, but that's it. 
Higer level plot data would be nice, but I could build that.  The
problem is getting a pack that does not require me messing with
installing many things.  If that's possible.

Thanks for any help.