title: numpy.asarray: how to check up that its result dtype is numeric?
body: <p>I have to create a <code>numpy.ndarray</code> from array-like data with int, float or complex numbers.</p>
  
  <p>I hope to do it with <code>numpy.asarray</code> function.</p>
  
  <p>I don't want to give it a strict <code>dtype</code> argument, because I want to convert complex values to <code>complex64</code> or <code>complex128</code>, floats to <code>float32</code> or <code>float64</code>, etc.</p>
  
  <p>But if I just simply run <code>numpy.ndarray(some_unknown_data)</code> and look at the dtype of its result, how can I understand, that the data is numeric, not object or string or something else?</p>