Cell styles

Set the font, fill, border, and alignment of individual cells

Use cell_styles when you know exactly which cell you want to change. Each entry names a position and carries any combination of font, fill, border, alignment, and number format.

jet.write_sheet_arrow(
    df.to_arrow(),
    "styled.xlsx",
    cell_styles=[
        {
            "row": 2,
            "col": 1,
            "font": {"bold": True, "color": "FF0000"},
            "fill": {"pattern": "solid", "fg_color": "FFFF00"},
        }
    ],
)

row is 1-based and col is 0-based, so cell B2 is {"row": 2, "col": 1}. See Conventions for the full indexing table.

To style cells based on the values they hold rather than where they sit, use conditional formatting instead.

Font

bold · bool

italic · bool

underline · bool

size · float

Point size.

color · str

Hex color. Six or eight digits both work.

name · str

Typeface, such as "Arial".

Fill

pattern · "solid" | "gray125" | "none"

Use solid for a flat background. gray125 gives light stippled shading.

fg_color · str

The fill color for solid.

bg_color · str

The background color behind a pattern.

This is how you shade a header row. styled_headers gives bold only, so add a cell_styles entry per header cell when you want a background color.

Border

Set left, right, top, and bottom independently. Each takes a style and a color.

style · "thin" | "medium" | "thick" | "double" | "dotted" | "dashed"

color · str

Hex color.

"border": {
    "left":   {"style": "thin",   "color": "000000"},
    "right":  {"style": "medium", "color": "000000"},
    "top":    {"style": "thick",  "color": "0070C0"},
    "bottom": {"style": "double", "color": "000000"},
}

Alignment

horizontal · "left" | "center" | "right" | "justify"

vertical · "top" | "center" | "bottom"

wrap_text · bool

Wraps long text inside the cell instead of letting it overflow.

text_rotation · int

Degrees, 0 to 180, or 255 for vertical text.

Rotation numbering isn’t obvious, so here’s what the ranges do:

0

No rotation. This is the default.

1 to 90

Counterclockwise. Use 45 to angle text up and to the right, which fits more header text into a narrow column.

91 to 180

Clockwise. 91 sits one degree below horizontal and 180 points straight down.

255

Vertical. Letters stack top to bottom without rotating.

Number format

number_format · str

Any built-in name or Excel format code. See Number formats.

Setting a format here overrides column_formats for that one cell.

A complete cell

cell_styles = [
    {
        "row": 1,
        "col": 0,
        "font": {"bold": True, "size": 14.0, "color": "FFFFFF", "name": "Arial"},
        "fill": {"pattern": "solid", "fg_color": "0070C0"},
        "border": {"bottom": {"style": "medium", "color": "000000"}},
        "alignment": {"horizontal": "center", "vertical": "center", "wrap_text": True},
        "number_format": "currency",
    }
]