new_contents: foods = ['spam', 'eggs', 'ham']
  things = foods
  things[1] = 'chips'
  print(foods[1])  # 'chips'
  print(foods)  # ['spam', 'chips', 'ham']
  print(things)  # ['spam', 'chips', 'ham']
  
  print(40 * '-')
  
  a = ['spam', 'eggs', 'ham']
  b = a
  c = a[:]
  print(a is b, a is c)  # (True, False)
  print(a == b, a == c)  # (True, True)
  b[1] = 'milk'
  print(a is b, a is c)  # (True, False)
  print(a == b, a == c)  # (True, False)
  
  print(40 * '-')
  
  my_string = '1234567890'
  print(my_string[9])
  
  print(40 * '-')
  
  my_data = set(range(15))
  print(my_data)
  
  for x in my_data:
      print(x)
      break
  
  print(40 * '-')
  
  
  
subject: add more about collections