Pretty sure that's a leucistic Texas rat snake. You might want to know that's not really a "smile" but I suppose you could consider it to be a "come hither" look?
Here's a past thread: (Note that the friendly & calm ones aren't going to be "smiling" at you, so be careful what you wish for. It's also not a yawn!)
https://ball-pythons.net/forums/show...snakes-to-keep