title: Initialize 2-D array uniformly in numpy
body: <p>I want to create a probability distribution stochastic policy for <strong>reinforcement learning</strong>.</p>
  
  <pre><code>e.i policy[s,a] = P(take action a | in state s), where n_states=500 and n_actions=6
  </code></pre>
  
  <p>Since we still use integer state and action representations, I need to use a 2-dimensional array to represent the policy.</p>
  
  <p>How can I initialize my policy <strong>uniformly</strong>? that is, probabilities of all actions should be equal.</p>