slice.md

slice

Slice rows from any part of a CSV. When an index is present, this only has to parse the rows in the slice (instead of all rows leading up to the start of the slice).

Table of Contents | Source: src/cmd/slice.rs | 📇🏎️🗃️

Description | Examples | Usage | Slice Options | Common Options

Description ↩

Returns the rows in the range specified (starting at 0, half-open interval). The range does not include headers.

If the start of the range isn't specified, then the slice starts from the first record in the CSV data.

If the end of the range isn't specified, then the slice continues to the last record in the CSV data.

This operation can be made much faster by creating an index with 'qsv index' first. With an index, the command requires parsing just the rows that are sliced. Without an index, all rows up to the first row in the slice must be parsed.

Examples ↩

Slice from the 3rd record to the end

qsv slice --start 2 data.csv

Slice the first three records

qsv slice --start 0 --end 2 data.csv

Slice the first three records (using --len)

qsv slice --len 3 data.csv

Slice the last record

qsv slice -s -1 data.csv

Slice the last 10 records

qsv slice -s -10 data.csv

Get everything except the last 10 records

qsv slice -s -10 --invert data.csv

Slice the first three records of the last 10 records

qsv slice -s -10 -l 3 data.csv

Slice the second record

qsv slice --index 1 data.csv

Slice from the second record, two records

qsv slice -s 1 --len 2 data.csv

Slice records 10 to 20 as JSON

qsv slice --start 9 --end 19 --json data.csv

Slice records 1 to 9 and 21 to the end as JSON

qsv slice --start 9 --len 10 --invert --json data.csv

For more examples, see tests.

Usage ↩

qsv slice [options] [<input>]
qsv slice --help

Slice Options ↩

Option	Type	Description	Default
‑s, ‑‑start	string	The index of the record to slice from. If negative, starts from the last record.
‑e, ‑‑end	string	The index of the record to slice to.
‑l, ‑‑len	string	The length of the slice (can be used instead of --end).
‑i, ‑‑index	string	Slice a single record (shortcut for -s N -l 1). If negative, starts from the last record.
‑‑json	flag	Output the result as JSON. Fields are written as key-value pairs. The key is the column name. The value is the field value. The output is a JSON array. If --no-headers is set, then the keys are the column indices (zero-based).
‑‑invert	flag	slice all records EXCEPT those in the specified range.

Common Options ↩

Option	Type	Description	Default
‑h, ‑‑help	flag	Display this message
‑o, ‑‑output	string	Write output to instead of stdout.
‑n, ‑‑no‑headers	flag	When set, the first row will not be interpreted as headers. Otherwise, the first row will always appear in the output as the header row.
‑d, ‑‑delimiter	string	The field delimiter for reading CSV data. Must be a single character. (default: ,)

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Source: src/cmd/slice.rs | Table of Contents | README