### Sets and Mathematical Operations in Python

#### by kiawin

A description of matched sets mathematical operations in Python, taken from the Python Tutorial.

>>> # Demonstrate set operations on unique letters from two words >>> # unique letters in a >>> a = set('abracadabra') >>> b = set('alacazam') >>> a set(['a', 'r', 'b', 'c', 'd']) >>> >>> # letters in a but not in b - difference >>> a - b set(['r', 'd', 'b']) >>> >>> # letters in either a or b - union >>> a | b set(['a', 'c', 'r', 'd', 'b', 'm', 'z', 'l']) >>> >>> # letters in both a and b - intersection >>> a & b set(['a', 'c']) >>> >>> # letters in a or b but not both - symmetric difference >>> a ^ b set(['r', 'd', 'b', 'm', 'z', 'l'])