Does self.temperature in base.py need to be updated to a placeholder?

[mzl0707]

In senario_battle.py
def play():
acts[i] = models[i].act(state=state[i], prob=former_act_prob[i], eps=eps)

In base.py
def act():
self.temperature = kwargs['eps']

However, self.temperature is not put into feed_dict. I've noticed that it is a float instead of a tensor (i.e. tf.placeholder).
Is it just enough to be a float? What is the difference between float and placeholder in this specific case?