code: """
  Know more, visit my Python tutorial page: https://morvanzhou.github.io/tutorials/
  My Youtube Channel: https://www.youtube.com/user/MorvanZhou
  
  Dependencies:
  tensorflow: 1.1.0
  """
  import tensorflow as tf
  
  var = tf.Variable(0)    # our first variable in the "global_variable" set
  
  add_operation = tf.add(var, 1)
  update_operation = tf.assign(var, add_operation)
  
  with tf.Session() as sess:
      # once define variables, you have to initialize them by doing this
      sess.run(tf.global_variables_initializer())
      for _ in range(3):
          sess.run(update_operation)
          print(sess.run(var))
apis: tensorflow.global_variables_initializer tensorflow.add tensorflow.assign tensorflow.Session tensorflow.Variable