>>> import tensorflow as tf
>>> state = tf.Variable(0, name='counter')
>>> one = tf.constant(1)
>>> new_value = tf.add(state, one)
>>> update = tf.assign(state, new_value)
>>> init = tf.global_variables_initializer()
>>>
>>> with tf.Session() as sess:
...     sess.run(init)
...     for _ in range(3):
...             sess.run(update)
...             print(sess.run(state))


1
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2
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3