`rename`

Renames fields by exact mapping or regex patterns.

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

# Rename by exact mapping
undatum rename data.csv --map "old_name:new_name,old2:new2" --output output.csv

# Rename using regex
undatum rename data.jsonl --pattern "^prefix_" --replacement "" --output output.jsonl
undatum rename workbook.xlsx --table Sheet2 --map "city:city_name" --output out.jsonl

# Any writable format, chosen by extension
undatum rename data.csv --map "old_name:new_name" --output output.parquet

Reference

Reads: any readable format · Writes: any writable format; CSV/TSV/JSON/JSON Lines on stdout · Memory: streaming · Engines: auto, duckdb, python

undatum rename [OPTIONS] INPUT_FILE

Argument	Description
`INPUT_FILE`	Path to input file. (required)

Option	Description	Default
`-o`, `--output` TEXT	Optional output file path. If not specified, prints to stdout.
`--map` TEXT	Field name mapping: 'old_name:new_name,old2:new2'.
`--pattern` TEXT	Regex pattern to match field names (for regex-based renaming).
`--replacement` TEXT	Replacement string for regex pattern (default: empty string).
`-d`, `--delimiter` TEXT	CSV delimiter character (auto-detected when omitted).
`--quotechar` TEXT	CSV quote character (iterabledata default '"' when omitted).
`--encoding` TEXT	File encoding (e.g., 'utf8', 'latin1').
`--verbose` / `--no-verbose`	Enable verbose logging output.	`--no-verbose`
`-F`, `--format-in` TEXT	Override input file format detection (e.g., 'csv', 'jsonl').
`--table`, `--sheet` TEXT	Table or sheet name for multi-table sources (Excel, SQLite, lakehouse).
`--start-page` INTEGER	Sheet index (0-based) for Excel files.	`0`
`--trust`	Acknowledge pickle deserialization risk when reading pickle sources.
`--on-error` TEXT	Parse-error policy: raise (default), skip, or warn.
`--error-log` TEXT	Append parse errors as JSONL (use with --on-error skip or warn).
`--flatten-nested`	Unfold nested dict / array-of-dict fields into dotted paths (e.g. city.lat).
`--max-nested-depth` INTEGER	With --flatten-nested, maximum nest depth to unfold (engine default 5).
`--keep-nested-parents` / `--no-keep-nested-parents`	With --flatten-nested, keep parent dict/array fields alongside dotted children.	`--keep-nested-parents`
`-e`, `--engine` [auto\|duckdb\|python]	Processing engine: auto (default), duckdb, or python.
`-O`, `--format-out` TEXT	Output format (e.g. csv, jsonl, parquet). Defaults to the --output extension, or to the input's text format on stdout.

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Reference