the code is as follows

the database is created as follows

class HyperParameters(models.Model):
    graph = models.ForeignKey(Graph)
    train_times = models.PositiveIntegerField(default=10)
    save = models.BooleanField(default=True)
    learning_rate = models.FloatField(default=0.01)

    def __str__(self):
        return "{id}: {graph} {train_times} {save} {learning_rate}".format(id=self.id,
                                                                   graph=self.graph,
                                                                   train_times=self.train_times,
                                                                   save=self.save,
                                                                   learning_rate=self.learning_rate
                                                                   )

Why should I create data and always report errors in the diagram, such as

HyperParameters.objects.create(learning_rate=0.02)

always mean that BOOL object cannot be called?