QLearningDecisionPolicy not compatible tensorflow 2.0

[algobughk]

QLearningDecisionPolicy in chapter 11 of random_bandit_agent.py is not compatible with tensorflow 2.0

Traceback (most recent call last):

File "Chapter11\stock_price_predictive_agent.py", line 134, in
policy = QLearningDecisionPolicy(actions, hist + 2)

File "Chapter11\stock_price_predictive_agent.py", line 41, in init
self.x = tf.placeholder(tf.float32, [None, input_dim])

AttributeError: module 'tensorflow' has no attribute 'placeholder'