module tensorflow has no attribute session

According to TF 1:1 Symbols Map, in TF 2.0 you should use tf.compat.v1.Session() instead of tf.Session()

https://docs.google.com/spreadsheets/d/1FLFJLzg7WNP6JHODX5q8BDgptKafq_slHpnHVbJIteQ/edit#gid=0

To get TF 1.x like behaviour in TF 2.0 one can run

import tensorflow.compat.v1 as tf
tf.disable_v2_behavior()

sess = tf.compat.v1.Session()

print(sess.run(hello))

import tensorflow as tf

tf.compat.v1.disable_eager_execution()

hello = tf.constant('Hello, TensorFlow!')

sess = tf.compat.v1.Session()

print(sess.run(hello))

tf.compat.v1.GraphDef()   # -> instead of tf.GraphDef()
tf.compat.v2.io.gfile.GFile()   # -> instead of tf.gfile.GFile()

sess=tf.compat.v1.InteractiveSession()