Rainbow CSV
Main Features
- Highlight columns in comma (.csv), tab (.tsv), semicolon and pipe - separated files in different colors.
- Transform and filter tables using built-in SQL-like query language.
- Optional sticky header line.
- Provide info about column on hover.
- Automatic consistency check for csv files (CSVLint).
- Align columns graphically or with extra spaces and Shrink (trim spaces from fields).
- Multi-cursor column edit.
- Works in browser (vscode.dev).
Usage
Rainbow CSV looks better and is much more usable in general with dark mode.
You can manually enable highlighting by executing Set rainbow separator command or by clicking on the current language button in the bottom right corner and choosing one of the built-in CSV dialects from the table below.
Supported separators
| Language name |
Separator |
Extension |
Properties |
| csv |
, (comma) |
.csv |
Ignored inside double-quoted fields |
| tsv |
\t (TAB) |
.tsv .tab |
|
| csv (semicolon) |
; (semicolon) |
|
Ignored inside double-quoted fields |
| csv (whitespace) |
whitespace |
|
Consecutive whitespaces are merged |
| csv (pipe) |
| (pipe) |
|
|
| dynamic csv |
any char or string |
|
|
Content-based separator autodetection
Rainbow CSV runs a table 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 or 2 topmost lines.
Autodetection can be adjusted or disabled in the extension settings.
Customizing file extension - separator association
If you often work with csv 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:
"files.associations": {
"*.dat": "csv (pipe)",
"*.csv": "csv (semicolon)"
},
Important: language identifiers in the config must be specified in lower case! E.g. use csv (semicolon), not CSV (semicolon).
List of supported language ids: "csv", "tsv", "csv (semicolon)", "csv (pipe)", "csv (whitespace)", "dynamic csv".
Working with arbitrary separators
Rainbow CSV allows using an arbitrary character or string as a separator.
You can add the separator to the list of autodetected separators in the VSCode settings or if you just want to use it once you can either:
- Select
Dynamic CSV filetype (bottom right corner) and then enter the separator text in the popup dialog.
- Select the separator text with the cursor and run
Rainbow CSV: Set rainbow separator command.
Dynamic CSV filetype also supports multiline CSV fields escaped in double quotes as described in RFC-4180.
Note: In rare cases Dynamic CSV highlighting might not work at all due to compatibility issues with some other third-party extensions.
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 the file is bigger than 50MB.
Colors customization
You can customize Rainbow CSV colors to increase contrast, see Instructions.
This is especially helpful if you are using one of Light color themes.
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 to work properly with such files you need to adjust your settings.
Aligning/Shrinking table
There are 2 options to align a file:
- "Virtual Align" which does graphical alignment only without modifying the underlying file.
- Whitespace-based "Align" that inserts aligning whitespaces into the file.
You can align columns in CSV files by clicking "Align" status-line button or using the alignment command.
To shrink the table, i.e. remove leading and trailing whitespaces, click "Shrink" status-line button or use Shrink command
Settings
You can customize Rainbow CSV in the extension settings section of VSCode settings.
There you can find the list of available options and their description.
Commands:
Set rainbow separator
Set the currently selected text (single character or multiline string) as a separator and re-highlight the file.
Virtual Align
Align columns graphically (virtually) using VSCode inlay hints as extra spacing.
Unlike "Align" command that inserts extra spaces into the underlying file, "Virtual Align" doesn't modify the file itself.
Align, Shrink
Align columns by inserting extra whitespaces or shrink the columns (remove leading/trailing whitespaces)
ColumnEditBefore, ColumnEditAfter, ColumnEditSelect
Activate multi-cursor column editing for the 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.
Input a comma-separated string with column names to adjust column names displayed in hover tooltips. The actual header line and file content won't be affected.
"Virtual" header is persistent and will be associated with the parent file across VSCode sessions.
Uses the current line to adjust column names displayed in hover tooltips. The actual header line and file content won't be affected.
This is a "Virtual" header and will be persistent and will be associated with the parent file across VSCode sessions.
RBQL
Enter RBQL - SQL-like language query editing mode.
SetJoinTableName
Set a custom name for the current file so you can use it instead of the file path in RBQL JOIN queries
SQL-like "RBQL" query language
Rainbow CSV has a built-in RBQL query language interpreter that allows you to run SQL-like queries using a1, a2, a3, ... column names.
Example:
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 that would allow you to quickly and easily perform the most common data-manipulation tasks and convert your csv tables to bash scripts, single-line 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 the 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.
Full Documentation
Screenshot of RBQL Console:
Other
Comparison of Rainbow CSV technology with traditional graphical column alignment
Advantages:
- WYSIWYG
- 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.
- Color -> column association allows locating the column of interest more quickly when looking back and forth between the data and other objects on the screen (with column alignment one has to locate the header or count the columns to find the right one)
- Ability to visually associate two same-colored columns from two different windows. This is not possible with graphical column alignment
Disadvantages:
- Rainbow CSV may be less effective for CSV files with many (> 10) columns and for files with multiline fields, although textual alignment can significantly improve the situation.
- Rainbow CSV may be less usable with light mode because font colors become less distinguishable when compared to a dark mode (this phenomenon is also described here). This problem could be somewhat mitigated by using customized high-contrast rainbow colors (see color customization section).
References
These extensions can work well together with Rainbow CSV and provide additional functionality e.g. export to Excel format:
Rainbow CSV and similar plugins in other editors:
RBQL
- RBQL
- Library and CLI App for Python RBQL
- Library and CLI App for JavaScript RBQL
