title: How to find size of list/tuple in python in constant time
body: <p>I am a novice in Python. I was just wondering if one can find the length of list or tuple in O(1) time. <em>(len() is O(n))</em></p>
  
  <p>In C, I can achieve similar thing as follows:</p>
  
  <pre><code>int a[] = {1, 2, 3, 4 ,5};
  printf("Length of Array a is :: %d\n", sizeof(a)/sizeof(a[0]));
  </code></pre>
  
  <p>I know that the above concept works on addresses and that is why it is possible in C, while as per my understanding, Python does not deal in addresses. However I still wanted to ask this question for the sake of curiosity.</p>