[Evolution] Problems using Python script for signatures

[Trey Sizemore <trey fastmail fm>]

I have attempted to use a Python script (with some modifications) and
saved it as signature.py.  When I try to use it in Evolution (by going
to Composer Preferences -> Signatures -> Add Script and point to the
file in my home directory), I get an error message saying "Please
specify a valid script name."  What am I doing wrong?

Thanks,

Trey