code: def values(self):
          
          dtypes = [col.dtype for col in self.columns]
          if len(set(dtypes)) > 1:
              dtype = object
          else:
              dtype = None
          return np.array(self.columns, dtype=dtype).T
docs: Return data in `self` as a numpy array.
  
          If all columns are the same dtype, the resulting array
          will have this dtype. If there are >1 dtypes in columns,
          then the resulting array will have dtype `object`.