scastiel / csvread

An efficient CSV reader for the console.

CSVRead – An efficient CSV reader for the console

CSVRead is a command line program that you can use to query big CSV files, instead of opening them in Excel for instance.

I developed this program for personal use (inspired by querycsv.py), and to learn Rust.

Please consider it very WIP 😉

TL;DR

$ csvread path/to/file.csv \
    --select "name, age, [date of birth]"
    --where "name = 'Joe' and (age = '34' or age = '35')"

Installation

As the project is still work-in-progress, the installation is a pretty manual process, and you will need to install Rust on your machine first.

$ git clone https://github.com/scastiel/csvread
$ cd csvread
$ cargo build
$ cargo install --path .

Usage

USAGE:
    csvread [FLAGS] [OPTIONS] <filename>

ARGS:
    <filename>    The CSV file to read.

FLAGS:
    -c, --count      Counts the number of rows instead of displaying them.
    -h, --help       Prints help information
    -V, --version    Prints version information

OPTIONS:
    -s, --select <select>    List of columns to display, e.g "Col1, [Column 2]".
    -w, --where <where>      Query to filter the data, e.g "[My column] = 'the value'".

Features

Display a CSV in the console

$ csvread examples/weather.csv
Data.Precipitation Date.Full  Date.Month Date.Week of  ...
0.0                2016-01-03 1          3             ...
0.0                2016-01-03 1          3             ...
0.16               2016-01-03 1          3             ...
0.0                2016-01-03 1          3             ...

Tip: to display big file, you can pipe the command with the less command: csvread file.csv | less -S

Select the columns to display with --select

$ csvread example_data/weather.csv --select "Date.Full, [Station.City]"
Date.Full  Station.City
2016-02-07 Bettles
2016-02-14 Bettles
2016-02-21 Bettles
2016-02-28 Bettles

Separate the fields by commas, and use brackets [] for fields containing a space character or a comma, e.g. field, [my field], [my field, again].

Filter the rows with --where

$ csvread example_data/weather.csv --where "[Station.Location] = 'Bettles, AK' and [Date.Month] <> '1'"
Data.Precipitation Date.Full  Date.Month Date.Week of Date.Year Station.City
0.0                2016-02-07 2          7            2016      Bettles
0.24               2016-02-14 2          14           2016      Bettles
0.0                2016-02-21 2          21           2016      Bettles
0.0                2016-02-28 2          28           2016      Bettles

You can combine conditions using and and or logical operators, and parentheses () to group them.

The right operand needs to be surrounded by single quotes ', even for numbers.

The supported comparison operators are = (equality) and <> (difference).

Count the rows with --count (instead of displaying them)

$ csvread example_data/weather.csv --count
16,743 rows

$ csvread example_data/weather.csv --where "[Station.Location] = 'Bettles, AK' and [Date.Month] <> '1'" --count
47 rows (16,743 total)

LICENSE

MIT. See LICENSE.