human
Here's a good function header given the following:
I wrote the below code

    fontpaths = []
    def add(arg, directory, files):
        fontpaths.append(directory)
    for fontdir in OSXFontDirectories:
        try:
            if os.path.isdir(fontdir):
                os.path.walk(fontdir, add, None)
        except (IOError, OSError, TypeError, ValueError):
            pass
    return fontpaths

What's a good function header?
assistant
#Here's a good function header.

def OSXFontDirectory():