title: Pandas function to_numpy
body: <p>From pandas documentation, I found the function <code>to_numpy</code>
  <a href="https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.DataFrame.to_numpy.html" rel="nofollow noreferrer">https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.DataFrame.to_numpy.html</a>
  But when I tried it(the same example as in the documentation), I have:
  'DataFrame' object has no attribute 'to_numpy'.</p>
  <p>Do you know from where could be the problem?</p>