title: Generation of a nested list with different ranges
body: <p>Generation of a list of many lists each with different ranges </p>
  
  <pre><code>Isc_act = [0.1, 0.2, 0.3]
  I_cel = []
  a = []
  for i in range(0,len(Isc_act)):
      a = np.arange(0, Isc_act[i], 0.1*Isc_act[i])
      I_cel[i].append(a)
  print(I_cel)
  </code></pre>
  
  <p>Output is:</p>
  
  <pre><code>IndexError: list index out of range
  </code></pre>
  
  <p>My code is giving error. But, I want to get <code>I_cel = [[0,0.01,..,0.1],[0,0.02,0.04,...,0.2],[0, 0.03, 0.06,...,0.3]]</code>. Hence, the 'nested list' <code>I_cel</code> has three lists and each list has 10 values. </p>