codekingpro/portable-devtools

1from more_itertools import consume  # noqa: F4012 3 4# copied from jaraco.itertools 6.15def ensure_unique(iterable, key=lambda x: x):6    """7    Wrap an iterable to raise a ValueError if non-unique values are encountered.8 9    >>> list(ensure_unique('abc'))10    ['a', 'b', 'c']11    >>> consume(ensure_unique('abca'))12    Traceback (most recent call last):13    ...14    ValueError: Duplicate element 'a' encountered.15    """16    seen = set()17    seen_add = seen.add18    for element in iterable:19        k = key(element)20        if k in seen:21            raise ValueError(f"Duplicate element {element!r} encountered.")22        seen_add(k)23        yield element24