title: How do I disable TensorFlow's eager execution?
body: <p>I am trying to learn TensorFlow. Currently, I am working with placeholders. When I tried to create the placeholder, I got an error: <code>RuntimeError: tf.placeholder() is not compatible with eager execution</code>, which makes sense as placeholders are not executable immediately. </p>
  
  <p>So, how do I turn eager execution off?</p>
  
  <p>I have never turned eager execution on in the first place, so I am not sure how it happened. Is there an opposite to <code>tf.disable_eager_execution()</code>?</p>