input: Write a function to reverse a given list.
  def reverse_list(list): 
      return list[::-1]
  
  assert reverse_list([1,2,3,4,5])==[5,4,3,2,1]
  assert reverse_list([7,3,9,2,0])==[0,2,9,3,7]
  assert reverse_list(["a","b","c"])==["c","b","a"]
  assert reverse_list([])==[]
output: def reverse_list(list): 
      return list[::-1]