#dedupe
Remove or find repeated values.
- duplicates(items) +1List the values that repeat, or the ones that appear exactly once.
- has_duplicates(items)Return True as soon as any value repeats, even in a huge or endless iterable.
- union_by(a, b, key)Merge two lists, keeping the first item for each key, in a predictable order.
- unique_elements(items)De-duplicate a list while keeping the first occurrence of each value, in order.