title: Take one item from a list and append it/extend it to a new list
body: <p>I am very new to programming and I am trying to practice lists and for loops. I am trying to take one item from a list and append/extend it to a new list if it meets the condition  Some of the elements of the lists, clearly don't meet the condition but somehow they end up in my output. What am I doing wrong? Thank you for taking the time to answer</p>
  <pre><code>hours=[12, 5, 6, 4.6, 3]
  a=[]
  for i in hours:
      if i % 2==0 :
          a.extend(hours)
          del hours [:]
  print(a)
  </code></pre>