On Tue, 25 Feb 2014 23:07:28 +0000, MRAB wrote: > On 2014-02-25 21:27, Ben Finney wrote:
>> Or rather, sets *only* have values. Dictionaries have keys, sets do not >> have keys. >> > But a dictionary can have duplicate values, a set cannot. It is usual to talk about the things stored in dicts and sets using slightly different terminology: - mappings such as dicts have *key/value pairs* - sets have *elements* The elements of a set are most closely related to the keys of a mapping, not the values. Set elements are unique, just like mapping keys. Specifically, the keys in a mapping make up a set; the values in a mapping do not. When talking specifically about Python dicts and sets, there is an additional restriction: both set elements and dict keys have to be hashable. English being a little sloppy at times, sometimes we also talk about the *values of a set*, but here "value" is being used as a synonym for "element" and not as a technical term for the thing which mappings associate with a key. -- Steven -- https://mail.python.org/mailman/listinfo/python-list
