Newcomer to Python tutorial question

[Alan Cameron]

I am not sure of this is the right place to ask a question about the 
tutorial

http://docs.python.org/3.0/tutorial/datastructures.html#sets

why is the printed result of

>>> basket = {'apple', 'orange', 'apple', 'pear', 'orange', 'banana'}
>>> print(basket)
{'orange', 'banana', 'pear', 'apple'}

in the sequence given?

-- 
Alan Cameron