title: check if any of the values is `None` in `numpy.array`
body: <p>I have a 2D <code>numpy.array</code>, which should act as indices for another, so it should contain only <code>int</code>s or <code>bool</code>s. Is there a quick and elegant (one line) way for checking for this condition?</p>
  <p>I've tried the following code, but it does not provide the desired output, as it only checks for <code>0</code>s and not for <code>None</code>s, which is the value present in my case:</p>
  <p><strong>Example 1:</strong></p>
  <pre><code>a = np.array([[1, 2, 3], [3, 4, 5]])
  np.all(type(a) == np.int64, axis=0)
  </code></pre>
  <p>Current Output 1:</p>
  <pre><code>False
  </code></pre>
  <p><strong>Example 2:</strong></p>
  <pre><code>b = np.array([[1, 2, None], [3, 4, 5]])
  np.all(type(a) == np.int64, axis=0)
  </code></pre>
  <p>Current Output 2:</p>
  <pre><code>False
  </code></pre>
  <p>so in the first example I'd like to get <code>True</code> as an output, as all the values of this array are numeric, while in example 2 - I'd like to get false, as there is a <code>None</code> value present in the first row of <code>b</code> array.
  Appreciate any help.</p>