sample

Randomly selects rows from a data file using reservoir sampling. Either --n or --percent is required.

Write with --output. A trailing path is not a positional argument.

# Sample fixed number of rows
undatum sample data.csv --n 1000 --output output.csv

# Sample by percentage
undatum sample data.jsonl --percent 10 --output output.jsonl

Key options: --n, --percent, --output, --engine, --format-in. Also accepts --table, --flatten-nested, --on-error, --error-log, and --quotechar (shared options).