float() argument must be a string or a number, not 'numpy.dtype' code example

Example 1: float() argument must be a string or a number, not 'dict_values'

>>> np.array(list(d.values())).astype(float)
array([ 2.,  4.])

Example 2: float() argument must be a string or a number, not 'dict_values'

>>> np.array(d.values())
array(dict_values([2, 4]), dtype=object)