title: Remove a list inside a list
body: <p>I want to remove the list [1,2,3] inside the outer list.
  I tried <code>or isinstance(item, list)</code> but that didn't work, the nested list was still there.</p>
  
  <pre><code>messy_list = ["a", 2, 3, 1, False, [1, 2, 3]]
  
  # Your code goes below here
  messy_list.pop(3)
  messy_list.insert(0,1)
  
  for item in messy_list:
      if isinstance(item, str) or isinstance(item, bool):
          messy_list.remove(item)
  
  messy_list.pop(-1)
  
  print(messy_list)
  </code></pre>
  
  <p>I would like to know if there wasn't a better way to check if there's a list inside the list, and then remove from the outer list, instead of having to hardcode it with .pop(-1)</p>