enum

Adds row numbers, UUIDs, or constant values to records. Useful for adding unique identifiers or sequential numbers.

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

# Add row numbers (default field: row_id, starts at 1)
undatum enum data.csv --output output.csv

# Add UUIDs
undatum enum data.jsonl --field id --type uuid --output output.jsonl

# Add constant value
undatum enum data.csv --field status --type constant --value "active" --output output.csv

# Custom starting number
undatum enum data.jsonl --field sequence --start 100 --output output.jsonl
undatum enum workbook.xlsx --table Sheet2 --field row_id --output out.jsonl

Key options: --field, --type (sequence, uuid, constant), --start, --value, --output. Also accepts --table, --flatten-nested, --on-error, --error-log, and --quotechar (shared options).