List comprehensions :

  provide a concise way to create lists.

  squares = []
  for x in range(10):
  squares.append(x**2)
  squares
  [0, 1, 4, 9, 16, 25, 36, 49, 64, 81]

  Delete element from list

 a = [-1, 1, 66.25, 333, 333, 1234.5]
 del a[0]