A Ruby array of hashes with symbol keys.
Who uses it
Rails seed files and Ruby scripts.
Writing Ruby
Column names are converted to valid symbol names, which means non-word characters become underscores.
What is Ruby?
What it can hold
Ruby is source code. An array of hashes with symbol keys, which means column names become valid symbol names. A machine can read the table back out of it without guessing, which is what makes it safe to convert into and out of.
It keeps
- Types. A number stays a number and a boolean stays a boolean, so whatever reads the file next does not have to guess from how a value looks.
- The difference between empty and missing, which most table formats cannot express at all.
- Nested values. A cell can hold a list or an object rather than only a single value.
- A line break inside a cell, which survives rather than ending the row.
It cannot express
- Any formatting. Bold, colour, column widths and merged cells have nowhere to go.
- A partial read. The document has to be complete to mean anything, so a truncated file yields nothing and a large one has to be held in memory whole.
- A header row. Column names are repeated on every record instead, which is why a file in this format is larger than the table it holds.
What it looks like
staff = [
{ id: '007', name: 'Halima Yusuf', role: 'Analyst, data', started: '2024-03-15', hours: '38.5' },
{ id: '012', name: 'Jonah "Jo" Pryce', role: 'Engineer', started: '2025-11-02', hours: '' },
{ id: '104', name: 'Wei Chen', role: 'Manager', started: '2023-06-30', hours: '40' },
]Questions
How do I open Ruby files?
Ruby is written by Tablizer rather than read by it. Open the file in whichever tool the format belongs to.
Is Ruby a good format for sharing data?
It depends who is receiving it. Rails seed files and Ruby scripts. If the recipient is outside that group, a plain CSV travels further than anything else.