maps map in computer science is not like the map you used to read when going someplace in your car the term map is more mathematical term referring to function that maps domain to range you may have already used map in python maps are called by many names including dictionarieshash tablesand hash maps they are all the same data structure map or dictionary maps set of unique keys to their associated values much the way function maps value in the domain to the range key is what we provide to map when we want to look for the key/value pair the keys of map are unique there can only be one copy of specific key value in the dictionary at time as we saw in onepython has built-in support for dictionaries or maps here is some sample interaction with dictionary in the python shell python ( : feb : : [gcc (apple inc build )on darwin type "help""copyright""creditsor "licensefor more information { ["dog""catd["batman""jokerd["superman""lex lutherfor key in dprint(keybatman dog superman for key in dprint(key, [key]batman joker dog cat superman lex luther len( ["dog""skunkd["dog"'skunka mapor dictionaryis lot like set set and dictionary both contain unique values the set datatype contains group of unique values map contains set of unique keys that map to associated values like setswe can look up key in the mapand its associated valuein ( time as you might expectmapslike setsare implemented using hashing while the underlying implementation is the samemaps and sets are used differently the table below provides the methods and operators of maps or dictionaries and their associated complexities the operations in the table above have the expected complexities given hashing implementation as was presented in sect the interesting difference is that key/value pairs are stored in the dictionary as opposed to just the items of set the key part of the key/value pair is used to determine if key is in the dictionary as you might expect the value is returned when appropriate this copy belongs to 'acha