title: Creating a list in Python with multiple copies of a given object in a single line
body: <p>Suppose I have a given Object (a string "a", a number - let's say 0, or a list <code>['x','y']</code> )</p>
  
  <p>I'd like to create list containing many copies of this object, but without using a for loop:</p>
  
  <p><code>L = ["a", "a", ... , "a", "a"]</code></p>
  
  <p>or</p>
  
  <p><code>L = [0, 0, ... , 0, 0]</code></p>
  
  <p>or </p>
  
  <p><code>L = [['x','y'],['x','y'], ... ,['x','y'],['x','y']]</code></p>
  
  <p>I'm especially interested in the third case. 
  Thanks!</p>