Shorly after publishing Planter, user cavalierex brought Cookiecutter to my attention on the forum. It appears to be a complete replacement and is far more mature than Planter.
I don’t regret making Planter — it fits my own needs perfectly. If I’d known about cookiecutter before starting, though, I probably wouldn’t have bothered reinventing the wheel. It was still fun to code Planter.
Cookiecutter is so close in functionality that I thought it would be worth sharing. If Planter works well for you, great, but if you want an alternative, check it out.