def delete(self, doc):
        if doc.id is None:
            raise DatabaseException('Document does not have id')
        if doc.sid is None:
            try:
                rs = self.db.docs.remove({'id': doc.id}, safe=True)
                assert rs['n'] == 1
            except Exception as e:
                raise DatabaseException(e)
            return None
        doc.data = None
        return self.update(doc)
def __init__(self):
        # Fix some key bindings
        self.bind("<Control-Key-a>", self.select_all)
        # We will need Ctrl-/ for the "stroke", but it cannot be unbound, so
        # let's prevent it from being passed to the standard handler
        self.bind("<Control-Key-/>", lambda event: "break")
        # Diacritical bindings
        for a, k in self.accents:
            # Little-known feature of Tk, it allows to bind an event to
            # multiple keystrokes
            self.bind("<Control-Key-%s><Key>" % k,
                      lambda event, a=a: self.insert_accented(event.char, a))