title: Replacing an item in a python list by index.. failing?
body: <p>Any idea why when I call:</p>
  
  <pre><code>&gt;&gt;&gt; hi = [1, 2]
  &gt;&gt;&gt; hi[1]=3
  &gt;&gt;&gt; print hi
  [1, 3]
  </code></pre>
  
  <p>I can update a list item by its index, but when I call:</p>
  
  <pre><code>&gt;&gt;&gt; phrase = "hello"
  &gt;&gt;&gt; for item in "123":
  &gt;&gt;&gt;     list(phrase)[int(item)] = list(phrase)[int(item)].upper()
  &gt;&gt;&gt; print phrase
  hello
  </code></pre>
  
  <p>It fails? </p>
  
  <p>Should be <code>hELLo</code></p>