First and last rows

first and last keep the first or the last records of the file, in file order.

tabalyst sample customers.csv --sample-method first --rows 1000
tabalyst sample customers.csv --sample-method last --rows 1000

Key points

• Use it when you only need the start or the end of the file.
• Size: --rows or --percent, exactly one.
• Cost: one reading of the file.
• Seed: none. The rows are kept in file order, so --seed is an error with these methods (exit code 2).
• Output: customers.sample.csv beside the source.

Limits

• The rows are not chosen to represent the file. For the proportions use a random or stratified sample; for the rare cases use a smart sample.
• --seed, --field, --max-strata, --yes and --no-html are errors with these methods (exit code 2).

See Tabalyst Sample for sizes, output locations and CSV formats.