import tensorflow as tf
state=tf.Variable(0,name='counter')
#print(state.name)
one=tf.constant(1)

new_value=tf.add(state,one)
update=tf.assign(state,new_value)
init=tf.initialize_all_variables() #must have it!!
with tf.Session() as sess:
    sess.run(init)#must have it!!
    for _ in range(3):
     sess.run(update)
     print(sess.run(state))

