title: Time to assign a variable in Python
body: <p>Suppose I have the following in a really tight loop:</p>
  
  <pre><code>a = func(x)
  b = func2(a)
  </code></pre>
  
  <p>The variable <code>a</code> is not used anywhere else.</p>
  
  <p>Does Python automatically compile away the assignment to <code>a</code>, or does it take the time to do the variable assignment every time? In other words, is this code identical, or is it marginally faster due to the lack of assigning to <code>a</code>?</p>
  
  <pre><code>b = func2(func(x))
  </code></pre>
  
  <p>Is the behavior the same for Python2.7 vs Python3?</p>