From Computer Science Wiki
Programming basics[1]

A set is an abstract data type that can store certain values, without any particular order, and no repeated values. It is a computer implementation of the mathematical concept of a finite set. Unlike most other collection types, rather than retrieving a specific element from a set, one typically tests a value for membership in a set.[2]


These examples are used from[3] with gratitude.

 a = set('abracadabra')
 b = set('alacazam')
 a                                  # unique letters in a
{'a', 'r', 'b', 'c', 'd'}
 a - b                              # letters in a but not in b
{'r', 'd', 'b'}
 a | b                              # letters in a or b or both
{'a', 'c', 'r', 'd', 'b', 'm', 'z', 'l'}
 a & b                              # letters in both a and b
{'a', 'c'}
 a ^ b                              # letters in a or b but not both
{'r', 'd', 'b', 'm', 'z', 'l'}


  • Construct algorithms using pre- defined sub-programmes, one- dimensional arrays and/or collections.