Add functions to get list of keys, values and items from dicts efficiently #128
Description
Originally reported by: Antti Haapala (Bitbucket: antti_haapala, GitHub: Unknown)
There are often cases where old Python 2 code uses dict.keys() to create a copy of the keys and then iterates over the copy while the original dictionary is being modified. For such cases there should be the listkeys, listitems and listvalues that would be mapped to keys, items and values on Python 2, and list()-wrapped versions thereof in Python 3.
- Bitbucket: https://bitbucket.org/gutworth/six/issue/128