matplotlib.axes.Axes.legend#

Axes.legend(*args, **kwargs)[source]#

Place a legend on the Axes.

Call signatures:

legend()
legend(handles, labels)
legend(handles=handles)
legend(labels)

The call signatures correspond to the following different ways to use this method:

1. Automatic detection of elements to be shown in the legend

The elements to be added to the legend are automatically determined, when you do not pass in any extra arguments.

In this case, the labels are taken from the artist. You can specify them either at artist creation or by calling the set_label() method on the artist:

ax.plot([1, 2, 3], label='Inline label')
ax.legend()

or:

line, = ax.plot([1, 2, 3])
line.set_label('Label via method')
ax.legend()

Note

Specific artists can be excluded from the automatic legend element selection by using a label starting with an underscore, "_". A string starting with an underscore is the default label for all artists, so calling Axes.legend without any arguments and without setting the labels manually will result in no legend being drawn.

2. Explicitly listing the artists and labels in the legend

For full control of which artists have a legend entry, it is possible to pass an iterable of legend artists followed by an iterable of legend labels respectively:

ax.legend([line1, line2, line3], ['label1', 'label2', 'label3'])

3. Explicitly listing the artists in the legend

This is similar to 2, but the labels are taken from the artists' label properties. Example:

line1, = ax.plot([1, 2, 3], label='label1')
line2, = ax.plot([1, 2, 3], label='label2')
ax.legend(handles=[line1, line2])

4. Labeling existing plot elements

Discouraged

This call signature is discouraged, because the relation between plot elements and labels is only implicit by their order and can easily be mixed up.

To make a legend for all artists on an Axes, call this function with an iterable of strings, one for each legend item. For example:

ax.plot([1, 2, 3])
ax.plot([5, 6, 7])
ax.legend(['First line', 'Second line'])
Parameters:
handlessequence of Artist, optional

A list of Artists (lines, patches) to be added to the legend. Use this together with labels, if you need full control on what is shown in the legend and the automatic mechanism described above is not sufficient.

The length of handles and labels should be the same in this case. If they are not, they are truncated to the smaller length.

labelslist of str, optional

A list of labels to show next to the artists. Use this together with handles, if you need full control on what is shown in the legend and the automatic mechanism described above is not sufficient.

Returns:
Legend
Other Parameters:
locstr or pair of floats, default: rcParams["legend.loc"] (default: 'best') ('best' for axes, 'upper right' for figures)

The location of the legend.

The strings 'upper left', 'upper right', 'lower left', 'lower right' place the legend at the corresponding corner of the axes/figure.

The strings 'upper center', 'lower center', 'center left', 'center right' place the legend at the center of the corresponding edge of the axes/figure.

The string 'center' places the legend at the center of the axes/figure.

The string 'best' places the legend at the location, among the nine locations defined so far, with the minimum overlap with other drawn artists. This option can be quite slow for plots with large amounts of data; your plotting speed may benefit from providing a specific location.

The location can also be a 2-tuple giving the coordinates of the lower-left corner of the legend in axes coordinates (in which case bbox_to_anchor will be ignored).

For back-compatibility, 'center right' (but no other location) can also be spelled 'right', and each "string" locations can also be given as a numeric value:

Location String

Location Code

'best'

0

'upper right'

1

'upper left'

2

'lower left'

3

'lower right'

4

'right'

5

'center left'

6

'center right'

7

'lower center'

8

'upper center'

9

'center'

10

bbox_to_anchorBboxBase, 2-tuple, or 4-tuple of floats

Box that is used to position the legend in conjunction with loc. Defaults to axes.bbox (if called as a method to Axes.legend) or figure.bbox (if Figure.legend). This argument allows arbitrary placement of the legend.

Bbox coordinates are interpreted in the coordinate system given by bbox_transform, with the default transform Axes or Figure coordinates, depending on which legend is called.

If a 4-tuple or BboxBase is given, then it specifies the bbox (x, y, width, height) that the legend is placed in. To put the legend in the best location in the bottom right quadrant of the axes (or figure):

loc='best', bbox_to_anchor=(0.5, 0., 0.5, 0.5)

A 2-tuple (x, y) places the corner of the legend specified by loc at x, y. For example, to put the legend's upper right-hand corner in the center of the axes (or figure) the following keywords can be used:

loc='upper right', bbox_to_anchor=(0.5, 0.5)
ncolsint, default: 1

The number of columns that the legend has.

For backward compatibility, the spelling ncol is also supported but it is discouraged. If both are given, ncols takes precedence.

propNone or matplotlib.font_manager.FontProperties or dict

The font properties of the legend. If None (default), the current matplotlib.rcParams will be used.

fontsizeint or {'xx-small', 'x-small', 'small', 'medium', 'large', 'x-large', 'xx-large'}

The font size of the legend. If the value is numeric the size will be the absolute font size in points. String values are relative to the current default font size. This argument is only used if prop is not specified.

labelcolorstr or list, default: rcParams["legend.labelcolor"] (default: 'None')

The color of the text in the legend. Either a valid color string (for example, 'red'), or a list of color strings. The labelcolor can also be made to match the color of the line or marker using 'linecolor', 'markerfacecolor' (or 'mfc'), or 'markeredgecolor' (or 'mec').

Labelcolor can be set globally using rcParams["legend.labelcolor"] (default: 'None'). If None, use rcParams["text.color"] (default: 'black').

numpointsint, default: rcParams["legend.numpoints"] (default: 1)

The number of marker points in the legend when creating a legend entry for a Line2D (line).

scatterpointsint, default: rcParams["legend.scatterpoints"] (default: 1)

The number of marker points in the legend when creating a legend entry for a PathCollection (scatter plot).

scatteryoffsetsiterable of floats, default: [0.375, 0.5, 0.3125]

The vertical offset (relative to the font size) for the markers created for a scatter plot legend entry. 0.0 is at the base the legend text, and 1.0 is at the top. To draw all markers at the same height, set to [0.5].

markerscalefloat, default: rcParams["legend.markerscale"] (default: 1.0)

The relative size of legend markers compared with the originally drawn ones.

markerfirstbool, default: True

If True, legend marker is placed to the left of the legend label. If False, legend marker is placed to the right of the legend label.

frameonbool, default: rcParams["legend.frameon"] (default: True)

Whether the legend should be drawn on a patch (frame).

fancyboxbool, default: rcParams["legend.fancybox"] (default: True)

Whether round edges should be enabled around the FancyBboxPatch which makes up the legend's background.

shadowbool, default: rcParams["legend.shadow"] (default: False)

Whether to draw a shadow behind the legend.

framealphafloat, default: rcParams["legend.framealpha"] (default: 0.8)

The alpha transparency of the legend's background. If shadow is activated and framealpha is None, the default value is ignored.

facecolor"inherit" or color, default: rcParams["legend.facecolor"] (default: 'inherit')

The legend's background color. If "inherit", use rcParams["axes.facecolor"] (default: 'white').

edgecolor"inherit" or color, default: rcParams["legend.edgecolor"] (default: '0.8')

The legend's background patch edge color. If "inherit", use take rcParams["axes.edgecolor"] (default: 'black').

mode{"expand", None}

If mode is set to "expand" the legend will be horizontally expanded to fill the axes area (or bbox_to_anchor if defines the legend's size).

bbox_transformNone or matplotlib.transforms.Transform

The transform for the bounding box (bbox_to_anchor). For a value of None (default) the Axes' transAxes transform will be used.

titlestr or None

The legend's title. Default is no title (None).

title_fontpropertiesNone or matplotlib.font_manager.FontProperties or dict

The font properties of the legend's title. If None (default), the title_fontsize argument will be used if present; if title_fontsize is also None, the current rcParams["legend.title_fontsize"] (default: None) will be used.

title_fontsizeint or {'xx-small', 'x-small', 'small', 'medium', 'large', 'x-large', 'xx-large'}, default: rcParams["legend.title_fontsize"] (default: None)

The font size of the legend's title. Note: This cannot be combined with title_fontproperties. If you want to set the fontsize alongside other font properties, use the size parameter in title_fontproperties.

alignment{'center', 'left', 'right'}, default: 'center'

The alignment of the legend title and the box of entries. The entries are aligned as a single block, so that markers always lined up.

borderpadfloat, default: rcParams["legend.borderpad"] (default: 0.4)

The fractional whitespace inside the legend border, in font-size units.

labelspacingfloat, default: rcParams["legend.labelspacing"] (default: 0.5)

The vertical space between the legend entries, in font-size units.

handlelengthfloat, default: rcParams["legend.handlelength"] (default: 2.0)

The length of the legend handles, in font-size units.

handleheightfloat, default: rcParams["legend.handleheight"] (default: 0.7)

The height of the legend handles, in font-size units.

handletextpadfloat, default: rcParams["legend.handletextpad"] (default: 0.8)

The pad between the legend handle and text, in font-size units.

borderaxespadfloat, default: rcParams["legend.borderaxespad"] (default: 0.5)

The pad between the axes and legend border, in font-size units.

columnspacingfloat, default: rcParams["legend.columnspacing"] (default: 2.0)

The spacing between columns, in font-size units.

handler_mapdict or None

The custom dictionary mapping instances or types to a legend handler. This handler_map updates the default handler map found at matplotlib.legend.Legend.get_legend_handler_map.

See also

Figure.legend

Notes

Some artists are not supported by this function. See Legend guide for details.

Examples

(Source code, png)

../../_images/legend_00_00.png

Examples using matplotlib.axes.Axes.legend#

Bar color demo

Bar color demo

Bar color demo
Bar Label Demo

Bar Label Demo

Bar Label Demo
Stacked bar chart

Stacked bar chart

Stacked bar chart
Grouped bar chart with labels

Grouped bar chart with labels

Grouped bar chart with labels
Plotting categorical variables

Plotting categorical variables

Plotting categorical variables
Fill Between and Alpha

Fill Between and Alpha

Fill Between and Alpha
Hat graph

Hat graph

Hat graph
Customizing dashed line styles

Customizing dashed line styles

Customizing dashed line styles
Lines with a ticked patheffect

Lines with a ticked patheffect

Lines with a ticked patheffect
Scatter plots with custom symbols

Scatter plots with custom symbols

Scatter plots with custom symbols
Scatter plots with a legend

Scatter plots with a legend

Scatter plots with a legend
Stackplots and streamgraphs

Stackplots and streamgraphs

Stackplots and streamgraphs
Stairs Demo

Stairs Demo

Stairs Demo
Contourf Hatching

Contourf Hatching

Contourf Hatching
Tricontour Demo

Tricontour Demo

Tricontour Demo
Secondary Axis

Secondary Axis

Secondary Axis
Plot a confidence ellipse of a two-dimensional dataset

Plot a confidence ellipse of a two-dimensional dataset

Plot a confidence ellipse of a two-dimensional dataset
Using histograms to plot a cumulative distribution

Using histograms to plot a cumulative distribution

Using histograms to plot a cumulative distribution
The histogram (hist) function with multiple data sets

The histogram (hist) function with multiple data sets

The histogram (hist) function with multiple data sets
Bar of pie

Bar of pie

Bar of pie
Labeling a pie and a donut

Labeling a pie and a donut

Labeling a pie and a donut
Polar Legend

Polar Legend

Polar Legend
Composing Custom Legends

Composing Custom Legends

Composing Custom Legends
Legend using pre-defined labels

Legend using pre-defined labels

Legend using pre-defined labels
Legend Demo

Legend Demo

Legend Demo
Mathtext

Mathtext

Mathtext
Rendering math equations using TeX

Rendering math equations using TeX

Rendering math equations using TeX
Parasite Simple

Parasite Simple

Parasite Simple
Parasite Axes demo

Parasite Axes demo

Parasite Axes demo
Parasite axis demo

Parasite axis demo

Parasite axis demo
Anatomy of a figure

Anatomy of a figure

Anatomy of a figure
Legend Picking

Legend Picking

Legend Picking
Patheffect Demo

Patheffect Demo

Patheffect Demo
TickedStroke patheffect

TickedStroke patheffect

TickedStroke patheffect
Plot 2D data on 3D plot

Plot 2D data on 3D plot

Plot 2D data on 3D plot
Parametric Curve

Parametric Curve

Parametric Curve
Asinh Demo

Asinh Demo

Asinh Demo
Multiple Yaxis With Spines

Multiple Yaxis With Spines

Multiple Yaxis With Spines
Custom tick formatter for time series

Custom tick formatter for time series

Custom tick formatter for time series
Group barchart with units

Group barchart with units

Group barchart with units
Simple Legend01

Simple Legend01

Simple Legend01
Simple Legend02

Simple Legend02

Simple Legend02
Quick start guide

Quick start guide

Quick start guide
Legend guide

Legend guide

Legend guide
Constrained Layout Guide

Constrained Layout Guide

Constrained Layout Guide
Tight Layout guide

Tight Layout guide

Tight Layout guide
Specifying Colors

Specifying Colors

Specifying Colors