title: time.process_time() giving constant value
body: <p>I'm trying to measure CPU time on my script with <code>time.process_time()</code>, but it is always returning the same value. Here's my code:</p>
  <pre class="lang-py prettyprint-override"><code>import time
  
  pt0 = time.process_time()
  secuencia = [int(num) for num in '2,9,5,14,4,13,1,7,6,12,11,3,8,10'.split(',')]
  
  pt1 = time.process_time()
  
  n = 0
  acumulado = 0
  for num in secuencia:
      if num &gt; n:
          n = num
      acumulado += num
  
  num_perdido = int(n*(n+1)/2 - acumulado)
  
  if num_perdido == 0:
      n += 1
      num_perdido = n
  
  pt2 = time.process_time()
  
  print('pt0 =', pt0)
  print('pt1 =', pt1)
  print('pt2 =', pt2)
  </code></pre>
  <p>The file <code>secuencia.txt</code> contains the following:</p>
  <pre><code>2,9,5,14,4,13,1,7,6,12,11,3,8,10
  </code></pre>
  <p>And the output is:</p>
  <pre><code>pt0 = 0.0625
  pt1 = 0.0625
  pt2 = 0.0625
  </code></pre>
  <p>Is it because of how the function works, or am I doing something wrong?</p>