Rainbow CSV: Main features
- Highlight columns in comma (.csv), tab (.tsv), semicolon and pipe - separated files in different colors
- Provide info about column on hover
- Automatic consistency check for csv files (CSVLint)
- Multi-cursor column edit
- Run queries in SQL-like language
- Lightweight and dependency-free
If your csv, semicolon-separated or tab-separated file doesn't have .csv or .tsv extension, you can manually enable highlighting by clicking on the current language label mark in the right bottom corner and then choosing "CSV", "TSV", "CSV (semicolon)" or "CSV (pipe)" depending on the file content, see this screenshot
Another way to do this: select one separator character with mouse cursor -> right click -> "Set as Rainbow separator"
||Ignored inside double-quoted fields
||Ignored inside double-quoted fields
||Consecutive whitespaces are merged
||~ ^ : " = . -
Content-based separator autodetection
Rainbow CSV will run spreadsheet autodetection algorithm for all "Plain Text" and "*.csv" files. In most cases this is a very cheap operation because autodetection usually stops after checking only 1-2 topmost lines.
Autodetection can be disabled at the extension settings page.
If a file has less then 10 non-comment lines, autodetection algorithm will skip it; the value can be adjusted in settings.
By default only comma, tab, semicolon and pipe are tried for autodetection, but you can adjust the list of candidate separators, add the following line to your VSCode config and edit it by removing or including any of the supported separators:
"rainbow_csv.autodetect_separators": ["\t", ",", ";", "|"],
If the autodetection algorithm made an error and highlighted non-csv file, you can press "Rainbow OFF" button inside the status line.
Customizing file extension - separator association
If you often work with spreadsheet files with one specific extension (e.g. ".dat") and you don't want to rely on the autodetection algorithm, you can associate that extension with one of the supported separators.
For example to associate ".dat" extension with pipe-separated files and ".csv" with semicolon-separated files add the following lines to your VS Code json config:
"*.dat": "csv (pipe)",
"*.csv": "csv (semicolon)"
Important: language identifiers in the config must be specified in lower case! E.g. use
csv (semicolon), not
List of supported language ids:
"csv", "tsv", "csv (semicolon)", "csv (pipe)", "csv (whitespace)", "csv (tilda)", "csv (caret)", "csv (colon)", "csv (double quote)", "csv (equals)", "csv (dot)", "csv (hyphen)"
CSVLint consistency check
The linter checks the following:
- consistency of double quotes usage in CSV rows
- consistency of number of fields per CSV row
To recheck a csv file click on "CSVLint" button.
Working with large files
To enable Rainbow CSV for very big files (more than 300K lines or 20MB) disable "Editor:Large File Optimizations" option in VS Code settings.
You can preview huge files by clicking "Preview... " option in VS Code File Explorer context menu.
All Rainbow CSV features would be disabled by VSCode if file is bigger than 50MB.
Some CSV files can contain comment lines e.g. metadata before the header line.
To allow CSVLint, content-based autodetection algorithms and Align, Shrink, ColumnEdit commands work properly with such files you need to adjust your settings.
You can align columns in CSV files by clicking "Align" statusline button or use Align command
To shrink the table, i.e. remove leading and trailing whitespaces, click "Shrink" statusline button or use Shrink command
You can customize Rainbow CSV at the extension settings section of VSCode settings.
There you can find the list of available options and their description.
Enter RBQL - SQL-like language query editing mode.
Align columns with whitespaces or shrink them (remove leading/trailing whitespaces)
ColumnEditBefore, ColumnEditAfter, ColumnEditSelect
Activate multi-cursor column editing for column under the cursor. Works only for files with less than 10000 lines. For larger files you can use an RBQL query.
WARNING: This is a dangerous mode. It is possible to accidentally corrupt table structure by incorrectly using "Backspace" or entering separator or double quote characters. Use RBQL if you are not sure.
To remove cursor/selection from the header line use "Alt+Click" on it.
Adjust column names displayed in hover tooltips. Actual header line and file content won't be affected.
Rainbow CSV always assumes the first row that is not a comment (if comments are enabled) as a header, so when there is no real header in a spreadsheet, you can use this command and provide comma-separated string with column names to create a "virtual" header for more comfortable data viewing. Accepted CSV format doesn't require you to customize all of the columns - this is useful when you want to name only some small subset of available columns. Note that you must provide comma-separated string no matter what separator is actually used in your spreadsheet file. "Virtual" header is persistent and will be associated with the parent file across VSCode sessions.
You can customize Rainbow CSV colors to increase contrast. Instructions
SQL-like "RBQL" query language
Rainbow CSV has built-in RBQL query language interpreter that allows you to run SQL-like queries using a1, a2, a3, ... column names.
SELECT a1, a2 * 10 WHERE a1 == "Buy" && a4.indexOf('oil') != -1 ORDER BY parseInt(a2), a4 LIMIT 100
To enter query-editing mode, execute RBQL VSCode command.
RBQL is a very simple and powerful tool which would allow you to quickly and easily perform most common data-manipulation tasks and convert your csv tables to bash scripts, single-lines json, single-line xml files, etc.
It is very easy to start using RBQL even if you don't know SQL. For example to cut out third and first columns use
SELECT a3, a1
You can use RBQL command for all possible types of files (e.g. .js, .xml, .html), but for non-table files only two variables: NR and a1 would be available.
Screenshot of RBQL Console:
- Unlike Rainbow CSV, which always treats first line as header, RBQL is header-agnostic i.e. it never treats first line as header, so to skip over header line add
WHERE NR > 1 to your query.
== to check for equality inside WHERE expressions.
Comparison of Rainbow CSV technology with traditional graphical column alignment
- Familiar editing environment of your favorite text editor
- Zero-cost abstraction: Syntax highlighting is essentially free, while graphical column alignment can be computationally expensive
- High information density: Rainbow CSV shows more data per screen because it doesn't insert column-aligning whitespaces.
- Ability to visually associate two same-colored columns from two different windows. This is not possible with graphical column alignment
- Rainbow CSV may be less effective for CSV files with many (> 10) columns.
- Rainbow CSV can't correctly handle newlines inside double-quoted CSV fields (well, theorethically it can, but only under specific conditions)