>>> x = [4,2,9,7,5]
>>> x
[4, 2, 9, 7, 5]
>>> x.sort()
>>> x
[2, 4, 5, 7, 9]
>>> x = [4,2,9,7,5]
>>> y = sorted(x)
>>> x
[4, 2, 9, 7, 5]
>>> y
[2, 4, 5, 7, 9]
>>> x = ["cows", 42, True, [1,2,3]]
>>> x.sort()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  TypeError: '<' not supported between instances of 'int' and 'str'
  >>>