Highlighting

Highlighting methods colour specific cells based on conditions. All highlighting methods accept fill (background colour) and color (text colour). If color is omitted, contrast is computed automatically (black or white).

highlight_max(in_col, scope="column", color=None, fill="yellow", exclude=None)

Highlight the maximum value in each selected column.

in_col str | list | Expr — Column(s) to apply to
scope "column" | "table", default "column" — Compute max per column or across all selected columns
color str | None, default None — Text colour (auto-contrast if None)
fill str, default "yellow" — Background fill colour
exclude str | list | None, default None — Columns to exclude when in_col is an expression

Example:

df.style().highlight_max("Revenue").show()

Company	Revenue	Profit	Growth	Employees_k
Apple	383.3	97.0	7.8	161
Microsoft	211.9	72.4	6.9	221
Google	307.4	73.8	8.7	182
Amazon	574.8	30.4	11.8	1541
Meta	134.9	39.1	16.4	67

highlight_min(in_col, scope="column", color=None, fill="lightblue", exclude=None)

Highlight the minimum value in each selected column.

in_col str | list | Expr — Column(s) to apply to
scope "column" | "table", default "column" — Compute min per column or across all selected columns
color str | None, default None — Text colour (auto-contrast if None)
fill str, default "lightblue" — Background fill colour
exclude str | list | None, default None — Columns to exclude

Example:

df.style().highlight_min("Profit").show()

Company	Revenue	Profit	Growth	Employees_k
Apple	383.3	97.0	7.8	161
Microsoft	211.9	72.4	6.9	221
Google	307.4	73.8	8.7	182
Amazon	574.8	30.4	11.8	1541
Meta	134.9	39.1	16.4	67

highlight_above(in_col, value, inclusive=False, scope="column", color=None, fill="yellow")

Highlight values strictly above (or equal to, if inclusive=True) a threshold.

in_col str | list | Expr — Column(s) to apply to
value float — Threshold value
inclusive bool, default False — Include the threshold value itself
scope "column" | "table", default "column" — Unused for this method (kept for API consistency)
color str | None, default None — Text colour
fill str, default "yellow" — Background fill colour

Example:

df.style().highlight_above("Growth", value=10.0).show()

Company	Revenue	Profit	Growth	Employees_k
Apple	383.3	97.0	7.8	161
Microsoft	211.9	72.4	6.9	221
Google	307.4	73.8	8.7	182
Amazon	574.8	30.4	11.8	1541
Meta	134.9	39.1	16.4	67

highlight_below(in_col, value, inclusive=False, scope="column", color=None, fill="yellow")

Highlight values strictly below (or equal to, if inclusive=True) a threshold.

in_col str | list | Expr — Column(s) to apply to
value float — Threshold value
inclusive bool, default False — Include the threshold value itself
scope "column" | "table", default "column" — Unused for this method (kept for API consistency)
color str | None, default None — Text colour
fill str, default "yellow" — Background fill colour

Example:

df.style().highlight_below("Profit", value=73).show()

Company	Revenue	Profit	Growth	Employees_k
Apple	383.3	97.0	7.8	161
Microsoft	211.9	72.4	6.9	221
Google	307.4	73.8	8.7	182
Amazon	574.8	30.4	11.8	1541
Meta	134.9	39.1	16.4	67

highlight_equal(in_col, value, color=None, fill="yellow")

Highlight cells whose value exactly equals the target.

in_col str | list | Expr — Column(s) to apply to
value float | str — Target value
color str | None, default None — Text colour
fill str, default "yellow" — Background fill colour

Example:

df.style().highlight_equal("Employees_k", value=182).show()

Company	Revenue	Profit	Growth	Employees_k
Apple	383.3	97.0	7.8	161
Microsoft	211.9	72.4	6.9	221
Google	307.4	73.8	8.7	182
Amazon	574.8	30.4	11.8	1541
Meta	134.9	39.1	16.4	67

highlight_between(in_col, low, high, scope="column", color=None, fill="yellow")

Highlight values within the range [low, high] (inclusive).

in_col str | list | Expr — Column(s) to apply to
low float — Lower bound (inclusive)
high float — Upper bound (inclusive)
scope "column" | "table", default "column" — Unused for this method
color str | None, default None — Text colour
fill str, default "yellow" — Background fill colour

Example:

df.style().highlight_between("Revenue", low=200.0, high=400.0).show()

Company	Revenue	Profit	Growth	Employees_k
Apple	383.3	97.0	7.8	161
Microsoft	211.9	72.4	6.9	221
Google	307.4	73.8	8.7	182
Amazon	574.8	30.4	11.8	1541
Meta	134.9	39.1	16.4	67

highlight_identical(in_col, color=None, fill="yellow")

Highlight rows where all specified columns share the same value. Unlike other highlight methods, this operates row-wise across columns.

in_col list[str] — Columns to compare (must be a list)
color str | None, default None — Text colour
fill str, default "yellow" — Background fill colour

Example:

df.style().highlight_identical(["Col_A", "Col_B"]).show()

actual	predicted
1	1
2	3
3	3
2	4
5	5

highlight_when(in_col, when, then_fill="yellow", then_color=None, exclude=None)

Highlight cells in in_col when a Polars expression when evaluates to True. The expression can reference any column, enabling cross-column conditions.

in_col str | list | Expr — Column(s) to colour
when pl.Expr — Boolean Polars expression
then_fill str, default "yellow" — Background colour when condition is True
then_color str | None, default None — Text colour when condition is True
exclude str | list | None, default None — Columns to exclude

Example:

import polars as pl

# Highlight Revenue where Growth > 15%
df.style().highlight_when(
    "Revenue",
    when=pl.col("Growth") > 15,
    then_fill="lightgreen"
).show()

Company	Revenue	Profit	Growth	Employees_k
Apple	383.3	97.0	7.8	161
Microsoft	211.9	72.4	6.9	221
Google	307.4	73.8	8.7	182
Amazon	574.8	30.4	11.8	1541
Meta	134.9	39.1	16.4	67