#mapping
Transform keys or values.
- collect_dictionary(d)Invert a dict so each value maps to the list of keys that had it.
- invert_dictionary(d)Swap keys and values with a dict comprehension; the last key wins on shared values.
- map_values(d, fn)Build a new dict with a function applied to each value, keeping the keys.
- pluck(records, key)Collect the value of a key from each dict, with None where it's missing.