Line Dedup

Line deduplication removes repeated entries, often while preserving the first occurrence. Decide whether Apple and apple are the same, whether spaces are trimmed, and whether blank lines count as duplicates. Those options can materially change identifiers, file paths, or log entries.

Test a small list with case differences, leading spaces, and a repeated blank line. Check whether original order survives; sorting before deduplication may hide when an entry first appeared. Keep the source text until you verify the result. For data keys, default to exact matching unless normalization is explicitly intended.