(gulp) newbie question - portablity of python

[Keygrass]

I first discovered Python from Leo Laporte on ZDTV.  Just like what he said,
the www.python.org web site says this:

The Python implementation is portable: it runs on many brands of UNIX, on
Windows, DOS, OS/2, Mac, Amiga... If your favorite system isn't listed here,
it may still be supported, if there's a C compiler for it. Ask around on
comp.lang.python -- or just try compiling Python yourself.


So ... my question is this: Is this really too good to be true?  What I want
to do it write the program on my  Win98se (at home) and then use that .exe
or .bat file (or whatever extension it is) at work which uses unix.

Basically, I want a build a program that will replace words and number on
another file.  For example, if I had a file called "Outdoor_sports" that
contained the word "baseball bat", I would want my program to change it so
it would say "football".

-cb