Hello StackOverflow community,

Using Google App Engine, I wrote a keyToSha256() method within a model class (extending db.Model) :

class Car(db.Model):
    def keyToSha256(self):
        keyhash = hashlib.sha256(str(self.key())).digest()
        return keyhash

When displaying the output (ultimately within a Django template), I get garbled text, for example :

?????_??!`?I?!?;?QeqN??Al?'2

I was expecting something more in line with this :

9f86d081884c7d659a2feaa0c55ad015a3bf4f1b2b0b822cd15d6c15b0f00a08

Am I missing something important ? Despite reading several guides on ASCII, Unicode, utf-8 and the like, I think I'm still far from mastering the secrets of string encoding/decoding. After browsing StackOverflow and searching for insights via Google, I figured out I should ask the question here. Any idea ? Thanks !