title: Python append values to empty list by skipping values in between a list
body: <p>Just a minimal example of what I want to achieve.</p>
  
  <p>I have an array:</p>
  
  <pre><code>array = [1,2,3,4,5,6,7,8,9,10,1,2,3,4,5,6,7,8,9,10,....,1,2,3,4,5,6,7,8,9,10]
  </code></pre>
  
  <p>I would like to loop through this array and create a new array which looks like this:</p>
  
  <pre><code>new_array = [1,1,2,1,2,3,1,2,3,4,1,2,3,4,5,....,1,2,3,4,5,6,7,8,9,10]
  </code></pre>
  
  <p>i.e. loop through array <code>a</code>, get the first value (i.e. 1), <strong>then skip the <code>remaining 9</code> values</strong>, then get the first and the second value (i.e. 1,2), <strong>then skip the <code>remaining 8</code> values</strong>, and so on. </p>
  
  <p>The idea I came up with was to create <code>indices</code> and use it in the following way:</p>
  
  <pre><code>In [1]: indices = np.arange(1,10,1)
  Out[1]: array([1, 2, 3, 4, 5, 6, 7, 8, 9])
  
  new_array = []
  for i in array:
      for a,b in zip(indices,range(10)):
          new_array.append(i[0:a]) # here I am including i[0:1], i[0:2] and so on 
  </code></pre>
  
  <p>So it loops through <code>array</code> and gets the first value, then skips the remaining 9 values, then gets the first two values and skips the remaining 8 values and so on. </p>
  
  <p>But this doesn't seem to work. How can I achieve this ? </p>