title: Python: how can I get rid of the second element of each sublist?
body: <p>I have a list of sublists, such as:</p>
  
  <p>[[501, 4], [501, 4], [501, 4], [501, 4]]</p>
  
  <p>How can I get rid of the second element for each sublist ? (i.e. 4)</p>
  
  <p>[501, 501, 501, 501]</p>
  
  <p>Should I iterate the list or is there a faster way ?
  thanks</p>