xsv—a fast CSV cli toolkit written in Rust

In recent years I've become an avid user of csvkit, a suite of command-line tools for converting to and working with CSV—which for me has become the king of tabular file formats.

Then, just recently, I've learned about xsv…

xsv is a command line program for indexing, slicing, analyzing, splitting and joining CSV files. Commands should be simple, fast and composable:

  1. Simple tasks should be easy.
  2. Performance trade offs should be exposed in the CLI interface.
  3. Composition should not come at the expense of performance.

And I must say, I really like the simplicity of it's commands and the balanced feature set they provide:

  • cat - Concatenate CSV files by row or by column.
  • count - Count the rows in a CSV file. (Instantaneous with an index.)
  • fixlengths - Force a CSV file to have same-length records by either
    padding or truncating them.
  • flatten - A flattened view of CSV records. Useful for viewing one record
    at a time. e.g., xsv slice -i 5 data.csv | xsv flatten.
  • fmt - Reformat CSV data with different delimiters, record terminators
    or quoting rules. (Supports ASCII delimited data.)
  • frequency - Build frequency tables of each column in CSV data. (Uses
    parallelism to go faster if an index is present.)
  • headers - Show the headers of CSV data. Or show the intersection of all
    headers between many CSV files.
  • index - Create an index for a CSV file. This is very quick and provides
    constant time indexing into the CSV file.
  • input - Read CSV data with exotic quoting/escaping rules.
  • join - Inner, outer and cross joins. Uses a simple hash index to make it
    fast.
  • partition - Partition CSV data based on a column value.
  • sample - Randomly draw rows from CSV data using reservoir sampling (i.e.,
    use memory proportional to the size of the sample).
  • reverse - Reverse order of rows in CSV data.
  • search - Run a regex over CSV data. Applies the regex to each field
    individually and shows only matching rows.
  • select - Select or re-order columns from CSV data.
  • slice - Slice rows from any part of a CSV file. 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).
  • sort - Sort CSV data.
  • split - Split one CSV file into many CSV files of N chunks.
  • stats - Show basic types and statistics of each column in the CSV file.
    (i.e., mean, standard deviation, median, range, etc.)
  • table - Show aligned output of any CSV data using
    elastic tabstops.