title: Python how to get a subset of a two-dimensional array?
body: <p>I have two lists:</p>
  
  <pre><code>&gt;&gt;&gt; a = ["question1", "question2", "question3", "question4", "question5"]
  &gt;&gt;&gt; b = ["php html", "html", "html", "java", "php"]
  </code></pre>
  
  <p>then I obtained a 2D array using:</p>
  
  <pre><code>&gt;&gt;&gt; c = (a,b)
  </code></pre>
  
  <p>Now I wish to create a subset of <code>c</code> to keep only the rows corresponding to question i to j.</p>
  
  <p>I tried:</p>
  
  <pre><code>c[i:j+1][0:1]
  </code></pre>
  
  <p>and many other things, but could not figure it out.</p>