create Python "make" file

[beliavsky at aol.com]

I know that you do not need a make file to run a Python program -- it
looks for the needed sources files in the working directory and in
directories in the path. But it is convenient to know what Python
source files a program uses, if you want to back up a program or send
it to a colleague.

Has anyone written a Python tool that looks at all the Python source
files in a directory and constructs lists of sources, each of which
comprises a program?