gistfile1.py

init python:

    def openpdf(fn):
        import os.path
        import subprocess
    
        fn = os.path.join(config.gamedir, fn)
        fn = renpy.fsencode(fn)

        try:
            if renpy.windows:
                os.startfile(fn)
            elif renpy.macintosh:
                subprocess.Popen([ "open", fn ])
            else:
                subprocess.Popen([ "xdg-open", fn])
        except:
            if config.developer:
                raise