On Mon, Jan 11, 2016 at 11:57 PM, Tier Nolan <tier.nolan@gmail.com> wrote:
>
>     else:
>         script = "CHECKSIG %s OP_DROP" % (prev_hash, const_pub_key)
>

That should be

script = "%s CHECKSIG %s OP_DROP" % (const_pub_key, prev_hash)