title: Pandas dataframe from numpy with last dimension as object
body: <p>Convert 3d numpy array to pandas dataframe with numpy.array as elements.<br />
  Are there any other solutions? What about speed?</p>
  <pre><code>import numpy as np
  import pandas as pd    
      
  ones = np.ones((2,3,5))
  temp = [[np.array(column_elem, dtype=np.object) for column_elem in row] for row in ones]
  df = pd.DataFrame(temp)
  </code></pre>