Generalized Dictionaries

The keys of dictionaries are no longer restricted to strings - they can be numbers, tuples, or (certain) class instances. (Lists and dictionaries are not acceptable as dictionary keys, in order to avoid problems when the object used as a key is modified.)

Dictionaries have two new methods: d.values() returns a list of the dictionary's values, and d.items() returns a list of the dictionary's (key, value) pairs. Like d.keys(), these operations are slow for large dictionaries. Examples:

        >>> d = {100: 'honderd', 1000: 'duizend', 10: 'tien'}
        >>> d.keys()
        [100, 10, 1000]
        >>> d.values()
        ['honderd', 'tien', 'duizend']
        >>> d.items()
        [(100, 'honderd'), (10, 'tien'), (1000, 'duizend')]
        >>>