title: I can't find documentation on how to iterate across items in two lists serially, just in parallel
body: <p>I want to execute the same effect as the below code, but there has to be a way to do it in one (possibly nested) for loop, right?</p>
  <p>list_1 and list_2 have a bunch of numbers. I need to sort the contents into a list for odds and a list for evens. The below works, but seems inelegant. Is there a way to combine the two for loops into one?</p>
  <pre><code># parse list_1
  for i in list_1:
      if i % 2 == 0:
          list_even.append(i)
      else:
          list_odd.append(i)
  
  # parse list_2
  for i in list_2:
      if i % 2 == 0:
          list_even.append(i)
      else:
          list_odd.append(i)
  </code></pre>