title: Keras : AttributeError: 'int' object has no attribute 'ndim' when using model.fit
body: <h1>when triying to fit the model  i get this error</h1>
  
  <p>i'm using Keras and every time i try to fit my model</p>
  
  <pre><code>padded_model.fit(train_X, train_y, epochs=50, verbose=1)
  </code></pre>
  
  <p>i get this error :</p>
  
  <blockquote>
    <p>'int' object has no attribute 'ndim'</p>
  </blockquote>