title: to_numpy not returning float in python
body: <p>I have a dataframe wji that is created and I want to convert it to a float. When I run to_numpy it converts my dataframe as a 2D array as expected by the dtype is not float and is actually object. I thought to_numpy converted to a float</p>
  
  <pre><code>print(wji)
  wji = wji.to_numpy()
  wji.astype(float)
  print(wji.dtype)
  print(wji)
  
                 0          1          2          3
  m00     0.265211   0.181399   0.111651 -0.0847051
  mu02   -0.028225  0.0962054   0.113064  -0.213155
  mu11  -0.0357038   0.208511  0.0182606   0.320326
  mu20    0.351853  -0.161808  -0.129546  0.0154996
  mu03  -0.0295777   -0.32005    0.27918  -0.252604
  mu12    0.289506   0.176424   0.327829   0.309716
  mu21 -0.00807781  0.0486644  -0.266619   0.211797
  mu30    0.260602  -0.222457   0.044188  0.0241173
  object
  [[0.2652110197196954 0.18139929673003075 0.11165104327710718
    -0.08470512466140445]
   [-0.02822495204464942 0.09620543158200529 0.11306380462982002
    -0.21315489965597814]
   [-0.03570382418488832 0.20851099678961427 0.018260584909711663
    0.3203261779270866]
   [0.3518532632204968 -0.16180755912222522 -0.12954580116058592
    0.015499553874823824]
   [-0.02957772808836734 -0.3200497237343074 0.279179861454914
    -0.2526041954889673]
   [0.2895059792721121 0.17642419095938044 0.3278292712959946
    0.30971597348796753]
   [-0.008077807534792092 0.04866444048641794 -0.2666191448153845
    0.21179737334015403]
   [0.26060214043724306 -0.22245697799194314 0.044188046165909045
    0.02411734493263573]]
  </code></pre>