def multi_getter(source, *ids):
'''Get values from `source` of all given `ids`.
:param source: Any object but dealing with differences between mappings
and other object types.
:param ids: Identifiers to get values from `source`.
An ID item could be:
- a string: is considered a key, if `source` is a mapping, or an
attribute name if `source` is an instance of any other type.
- a collection of strings: find the first valid value in `source`
evaluating each item in this collection using the above logic.
Example::
>>> d = {'x': 1, 'y': 2, 'z': 3}
>>> list(multi_getter(d, 'a', ('y', 'x'), ('x', 'y'), ('a', 'z', 'x')))
[None, 2, 1, 3]
>>> next(multi_getter(d, ('y', 'x'), ('x', 'y')), '---')
2
>>> next(multi_getter(d, 'a', ('b', 'c'), ('e', 'f')), '---') is None
True
.. versionadded:: 1.7.1
'''
from collections import Iterable as multi
from xoutil.eight import string_types as strs
getter = smart_getter(source)
many = lambda a: isinstance(a, multi) and not isinstance(a, strs)
first = lambda a: next((i for i in map(getter, a) if i is not None), None)
get = lambda a: first(a) if many(a) else getter(a)
return (get(aux) for aux in ids)
def when_collection(source):
from xoutil.iterators import map
for generator in map(inner, source):
for key, val in generator:
yield key, val
