LineChart

A value along an ordered axis, one line per series. The Line Chart guide shows every feature on real data; this page is the contract: the function, the shape of its data, the keys style takes, and the constant each parameter accepts.

Function

datachart.charts.LineChart

LineChart(
    data: (
        list[LineDataPointAttrs]
        | list[list[LineDataPointAttrs]]
    ),
    *,
    title: str | None = None,
    xlabel: str | None = None,
    ylabel: str | None = None,
    subtitle: str | list[str | None] | None = None,
    emphasis: (
        EMPHASIS | str | list[str | None] | None
    ) = None,
    emphasis_rule: EmphasisRuleAttrs | None = None,
    figsize: FIG_SIZE | tuple[float, float] | None = None,
    xmin: int | float | datetime | None = None,
    xmax: int | float | datetime | None = None,
    ymin: int | float | None = None,
    ymax: int | float | None = None,
    show_legend: bool | None = None,
    legend: LegendSettingAttrs | None = None,
    show_grid: SHOW_GRID | str | bool | None = None,
    show_yerr: bool | None = None,
    show_area: bool | None = None,
    show_values: bool | None = None,
    value_format: VALUE_FORMAT | str | None = None,
    value_step: int | None = None,
    aspect_ratio: ASPECT_RATIO | str | None = None,
    scalex: SCALE | str | None = None,
    scaley: SCALE | str | None = None,
    subplots: bool | None = None,
    max_cols: int | None = None,
    sharex: bool | None = None,
    sharey: bool | None = None,
    style: (
        LineStyleAttrs | list[LineStyleAttrs | None] | None
    ) = None,
    xticks: (
        list[int | float | datetime]
        | list[list[int | float | datetime]]
        | None
    ) = None,
    xticklabels: list[str] | list[list[str]] | None = None,
    xtickrotate: int | list[int | None] | None = None,
    yticks: (
        list[int | float] | list[list[int | float]] | None
    ) = None,
    yticklabels: list[str] | list[list[str]] | None = None,
    ytickrotate: int | list[int | None] | None = None,
    xticks_format: (
        VALUE_FORMAT | DATE_FORMAT | str | None
    ) = None,
    yticks_format: (
        VALUE_FORMAT | DATE_FORMAT | str | None
    ) = None,
    vlines: (
        VLineSettingAttrs
        | list[VLineSettingAttrs]
        | list[
            VLineSettingAttrs
            | list[VLineSettingAttrs]
            | None
        ]
        | None
    ) = None,
    hlines: (
        HLineSettingAttrs
        | list[HLineSettingAttrs]
        | list[
            HLineSettingAttrs
            | list[HLineSettingAttrs]
            | None
        ]
        | None
    ) = None,
    vspans: (
        VSpanSettingAttrs
        | list[VSpanSettingAttrs]
        | list[
            VSpanSettingAttrs
            | list[VSpanSettingAttrs]
            | None
        ]
        | None
    ) = None,
    hspans: (
        HSpanSettingAttrs
        | list[HSpanSettingAttrs]
        | list[
            HSpanSettingAttrs
            | list[HSpanSettingAttrs]
            | None
        ]
        | None
    ) = None,
    texts: (
        TextSettingAttrs
        | list[TextSettingAttrs]
        | list[
            TextSettingAttrs | list[TextSettingAttrs] | None
        ]
        | None
    ) = None,
    x: str | list[str | None] | None = None,
    y: str | list[str | None] | None = None,
    yerr: str | list[str | None] | None = None
) -> plt.Figure

Creates the line chart.

Lines connect ordered (x, y) points to show how a value changes along a continuous axis, typically time. Use it for trends, growth, and comparing the trajectories of several series on the same scale. For unordered categories use BarChart; for unconnected samples use ScatterChart.

Examples:

>>> from datachart.charts import LineChart
>>> figure = LineChart(
...     data=[
...         {"x": 1, "y": 5},
...         {"x": 2, "y": 10},
...         {"x": 3, "y": 15},
...         {"x": 4, "y": 20},
...         {"x": 5, "y": 25}
...     ],
...     title="Basic Line Chart",
...     xlabel="X",
...     ylabel="Y"
... )

PARAMETER	DESCRIPTION
data	The data points for the line chart(s). Can be a single list of data points for one chart, or a list of lists for multiple charts/subplots. TYPE: list[LineDataPointAttrs] | list[list[LineDataPointAttrs]]
title	The title of the chart. TYPE: str | None DEFAULT: None
xlabel	The x-axis label. TYPE: str | None DEFAULT: None
ylabel	The y-axis label. TYPE: str | None DEFAULT: None
subtitle	The subtitle(s) for individual charts. Used as legend labels. TYPE: str | list[str | None] | None DEFAULT: None
emphasis	The emphasis role(s) for individual charts, aligned like style: "background" mutes a chart (theme muted color, lowered alpha, thinner line, behind the others, no legend entry), "highlight" bolds it and brings it to the front, None leaves it unchanged. TYPE: EMPHASIS | str | list[str | None] | None DEFAULT: None
emphasis_rule	A rule that highlights the lines matching it and mutes the rest: {"above": v} or {"below": v} (strict), {"between": (lo, hi)} (inclusive), {"top": n} or {"bottom": n}, read against a summary of each line's own y values, chosen by by: "mean" (default), "median", "min", "max", or "sum". An explicit emphasis role wins, and a count ranks across every line. See EmphasisRuleAttrs. TYPE: EmphasisRuleAttrs | None DEFAULT: None
figsize	The size of the figure. TYPE: FIG_SIZE | tuple[float, float] | None DEFAULT: None
xmin	The minimum x-axis value. TYPE: int | float | datetime | None DEFAULT: None
xmax	The maximum x-axis value. TYPE: int | float | datetime | None DEFAULT: None
ymin	The minimum y-axis value. TYPE: int | float | None DEFAULT: None
ymax	The maximum y-axis value. TYPE: int | float | None DEFAULT: None
show_legend	Whether to show the legend. TYPE: bool | None DEFAULT: None
legend	The per-figure legend setting: title, location, column count and alignment; each field falls back to the theme. See LegendSettingAttrs. TYPE: LegendSettingAttrs | None DEFAULT: None
show_grid	Which grid lines to show (e.g., "both", "x", "y"); False draws none. TYPE: SHOW_GRID | str | bool | None DEFAULT: None
show_yerr	Whether to show y-axis error bars. TYPE: bool | None DEFAULT: None
show_area	Whether to show the area under the line. TYPE: bool | None DEFAULT: None
show_values	Whether to print each point's value above or below it. TYPE: bool | None DEFAULT: None
value_format	Format string for the value labels: a VALUE_FORMAT constant or any "{x:.1f}", "{:.1f}%", or "%g" style string. TYPE: VALUE_FORMAT | str | None DEFAULT: None
value_step	Label every Nth point (1 labels all of them). Defaults to the smallest step that keeps neighbouring labels apart. TYPE: int | None DEFAULT: None
aspect_ratio	The aspect ratio of the axes ("auto" or "equal"). See ASPECT_RATIO. TYPE: ASPECT_RATIO | str | None DEFAULT: None
scalex	The x-axis scale (e.g., "log", "linear"). TYPE: SCALE | str | None DEFAULT: None
scaley	The y-axis scale (e.g., "log", "linear"). TYPE: SCALE | str | None DEFAULT: None
subplots	Whether to create separate subplots for each chart. TYPE: bool | None DEFAULT: None
max_cols	Maximum number of columns in subplots (when subplots=True). TYPE: int | None DEFAULT: None
sharex	Whether to share the x-axis in subplots. TYPE: bool | None DEFAULT: None
sharey	Whether to share the y-axis in subplots. TYPE: bool | None DEFAULT: None
style	Style configuration(s) for the line(s). TYPE: LineStyleAttrs | list[LineStyleAttrs | None] | None DEFAULT: None
xticks	Custom x-axis tick positions. TYPE: list[int | float | datetime] | list[list[int | float | datetime]] | None DEFAULT: None
xticklabels	Custom x-axis tick labels. TYPE: list[str] | list[list[str]] | None DEFAULT: None
xtickrotate	Rotation angle for x-axis tick labels. TYPE: int | list[int | None] | None DEFAULT: None
yticks	Custom y-axis tick positions. TYPE: list[int | float] | list[list[int | float]] | None DEFAULT: None
yticklabels	Custom y-axis tick labels. TYPE: list[str] | list[list[str]] | None DEFAULT: None
ytickrotate	Rotation angle for y-axis tick labels. TYPE: int | list[int | None] | None DEFAULT: None
xticks_format	The x-axis tick label format: a DATE_FORMAT member or strftime pattern on a datetime axis, else a VALUE_FORMAT member or "{x:.1f}" style string. TYPE: VALUE_FORMAT | DATE_FORMAT | str | None DEFAULT: None
yticks_format	The y-axis tick label format, as xticks_format. TYPE: VALUE_FORMAT | DATE_FORMAT | str | None DEFAULT: None
vlines	Vertical line(s) to plot. TYPE: VLineSettingAttrs | list[VLineSettingAttrs] | list[VLineSettingAttrs | list[VLineSettingAttrs] | None] | None DEFAULT: None
hlines	Horizontal line(s) to plot. TYPE: HLineSettingAttrs | list[HLineSettingAttrs] | list[HLineSettingAttrs | list[HLineSettingAttrs] | None] | None DEFAULT: None
vspans	Vertical reference band(s) to shade, between two x positions. TYPE: VSpanSettingAttrs | list[VSpanSettingAttrs] | list[VSpanSettingAttrs | list[VSpanSettingAttrs] | None] | None DEFAULT: None
hspans	Horizontal reference band(s) to shade, between two y positions. TYPE: HSpanSettingAttrs | list[HSpanSettingAttrs] | list[HSpanSettingAttrs | list[HSpanSettingAttrs] | None] | None DEFAULT: None
texts	Text annotation(s) to draw. TYPE: TextSettingAttrs | list[TextSettingAttrs] | list[TextSettingAttrs | list[TextSettingAttrs] | None] | None DEFAULT: None
x	The key name in data for x-axis values (default: "x"). TYPE: str | list[str | None] | None DEFAULT: None
y	The key name in data for y-axis values (default: "y"). TYPE: str | list[str | None] | None DEFAULT: None
yerr	The key name in data for y-axis error values (default: "yerr"). TYPE: str | list[str | None] | None DEFAULT: None

RETURNS	DESCRIPTION
plt.Figure	The figure containing the line chart.

Data

Each record in data is a LineDataPointAttrs; the x, y and yerr parameters rename its keys.

datachart.typings.LineDataPointAttrs

Bases: TypedDict

The data point attributes for the line chart.

ATTRIBUTE	DESCRIPTION
x	The x-axis value. TYPE: int | float
y	The y-axis value. TYPE: int | float
yerr	The y-axis error value. TYPE: int | float | None

Style

style takes the keys of LineStyleAttrs. The chart also reads the shared groups it draws: value labels (ValueLabelStyleAttrs), the area fill (AreaStyleAttrs), reference lines (VLineStyleAttrs and HLineStyleAttrs), reference bands (VSpanStyleAttrs and HSpanStyleAttrs) and text annotations (TextStyleAttrs). Every key falls back to the theme, so the same keys set the default look through config.

datachart.typings.LineStyleAttrs

Bases: TypedDict

The typing for the line chart style.

ATTRIBUTE	DESCRIPTION
plot_line_color	The line color. TYPE: str | None
plot_line_alpha	The alpha value of the line. TYPE: float | None
plot_line_style	The line style. TYPE: LINE_STYLE | str | None
plot_line_marker	The line marker. TYPE: LINE_MARKER | str | None
plot_line_width	The line width. TYPE: int | float | None
plot_line_drawstyle	The line draw style. TYPE: LINE_DRAW_STYLE | str | None
plot_line_zorder	The zorder of the line. TYPE: int | float | None
plot_xticks_label_rotate	The label rotation of the xticks in the line chart. TYPE: int | float | None
plot_yticks_label_rotate	The label rotation of the yticks in the line chart. TYPE: int | float | None

Constants

The parameters that accept a constant, with the class in datachart.constants that lists its values.

Parameter	Constant
emphasis	EMPHASIS
figsize	FIG_SIZE
legend={"location": ..., "alignment": ...}	LEGEND_LOCATION, LEGEND_ALIGN
show_grid	SHOW_GRID
value_format	VALUE_FORMAT
aspect_ratio	ASPECT_RATIO
scalex	SCALE
scaley	SCALE
xticks_format	VALUE_FORMAT, DATE_FORMAT
yticks_format	VALUE_FORMAT, DATE_FORMAT