Loading a predefined function

edit

Have you tried attach or load? Or are you asking for something different?

Edit:

I imagine it would be a little challenging in the virtual machine. In the notebook interface, you should still be able to do it, though. Try using the link in the picture below:

Then you can refer to the data file foo.py by doing something like attach(DATA+"foo.py"), I think. The quote will be important, because I believe that DATA is already a string giving the data directory for that worksheet.

if you write your own Sage code, the better use the file extension .sage, not .py. Note that in .py files not all Sage library might be available.

There is also a catch that if you have .sage file, say, blah.sage, then Sage will create blah.py on the fly, possibly overwriting the existing blah.py.