[Feature]: Column value formatting for render.DataGrid / render.DataTable #2472

Category

Input/Output

Scope

Minor Enhancement

Problem

I'm porting a Shiny app from R to Python, and the one thing I can't reproduce is number formatting in a table. In R I did this:

DT::datatable(dat) |>
  DT::formatCurrency(
    columns = c("Invoice", "MSRP"),
    currency = "$",
    digits = 0
  )

So the grid holds real numbers, but the cells display values like $32,295.

In Python there doesn't seem to be an equivalent. DataGrid takes styles, which is great for CSS, but it only changes how a cell looks, not how the value is rendered.

Solution

What I'd love is a way to attach a display format to a column while the underlying value stays numeric, so sorting and filtering keep working. Something in the spirit of:

render.DataGrid(
    df,
    format={
        "MSRP": "$,.0f",
        "Invoice": "$,.0f",
    }
)

Whatever the API ends up being, the pieces I care about are currency, thousands separators, percentages, and controlling decimal places.

Alternatives (Optional)

The workarounds I can see both give something up:

• Format the values into strings before handing them to the grid. Now sorting is lexicographic and the numeric range filter turns into a text search, which is worse for the user than the unformatted numbers were.
• Leave them as raw floats and stuff the units in the column name. Works, but 32295.0 in a table of prices looks unfinished.

Example (Optional)

Impact (Optional)

No response

Contribution? (Optional)

No, just suggesting.