On Fri, May 27, 2016 at 06:43:35AM -0700, Steve Dower wrote:
Neat!
My bikeshed is coloured `dict.getmany(*keys, default=None)`,
"getmany" doesn't tell you, many of what?
and while returning a namedtuple might be cool, an iterator is probably the way to go.
The disadvantage of a namedtuple is that every invocation would create a new class, which is then used once and once only for a singleton instance. Could get very expensive. I don't think an iterator would be needed. The motivating use-case is for sequence unpacking: # apologies for breaking my own rule about realistic names fee, fi, fo, fum = mydict.getmany('fee', 'fi', 'fo', 'fum') so I don't think the lazy aspect of an iterator is useful. It's going to be consumed eagerly, and immediately. I think a regular tuple is better. That also matches the behaviour of itemgetter: py> d = {'fe': 1, 'fi': 2, 'fo': 3, 'fum': 4} py> from operator import itemgetter py> f = itemgetter('fe', 'fi', 'fo', 'fum') py> f(d) (1, 2, 3, 4) So the core functionality already exists, it's just hidden away in the operator module. (Guido's time machine strikes again.) Open questions: - Is it worth making this a dict method? +1 from me. - Name? "getvalues"? - Any other functionality? Possibly a keyword-only "default" argument: mydict.getvalues(*keys, default=None) On more shaky ground, how about a "pop" argument? mydict.getvalues(*keys, pop=True) will delete the keys as well as return the values. Use-case: methods (particularly __init__ or __new__) which take extra keyword args which need to be popped before calling super. def __init__(self, **kwargs): colour, height = kwargs.getvalues('colour', 'height', pop=True) super().__init__(**kwargs) self.process(colour, height) -- Steve