matplotlib.pyplot.legend#
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()
line, = ax.plot([1, 2, 3]) line.set_label('Label via method') ax.legend()
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
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'])
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.
labels list 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 : loc str or pair of floats, default: rcParams[«legend.loc»] (default: ‘best’ )
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.
The strings ‘upper center’ , ‘lower center’ , ‘center left’ , ‘center right’ place the legend at the center of the corresponding edge of the axes.
The string ‘center’ places the legend at the center of the axes.
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» location can also be given as a numeric value:
| Location String | Location Code |
|---|---|
| ‘best’ (Axes only) | 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 |
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)
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.
prop None or FontProperties or dict
The font properties of the legend. If None (default), the current matplotlib.rcParams will be used.
fontsize int or
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.
labelcolor str 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’ ).
numpoints int, default: rcParams[«legend.numpoints»] (default: 1 )
The number of marker points in the legend when creating a legend entry for a Line2D (line).
scatterpoints int, default: rcParams[«legend.scatterpoints»] (default: 1 )
The number of marker points in the legend when creating a legend entry for a PathCollection (scatter plot).
scatteryoffsets iterable 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] .
markerscale float, default: rcParams[«legend.markerscale»] (default: 1.0 )
The relative size of legend markers compared to the originally drawn ones.
markerfirst bool, 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.
reverse bool, default: False
If True, the legend labels are displayed in reverse order from the input. If False, the legend labels are displayed in the same order as the input.
Whether the legend should be drawn on a patch (frame).
fancybox bool, default: rcParams[«legend.fancybox»] (default: True )
Whether round edges should be enabled around the FancyBboxPatch which makes up the legend’s background.
shadow bool, default: rcParams[«legend.shadow»] (default: False )
Whether to draw a shadow behind the legend.
framealpha float, 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’ ).
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_transform None or Transform
The transform for the bounding box (bbox_to_anchor). For a value of None (default) the Axes’ transAxes transform will be used.
title str or None
The legend’s title. Default is no title ( None ).
title_fontproperties None or 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.
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 , 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.
borderpad float, default: rcParams[«legend.borderpad»] (default: 0.4 )
The fractional whitespace inside the legend border, in font-size units.
labelspacing float, default: rcParams[«legend.labelspacing»] (default: 0.5 )
The vertical space between the legend entries, in font-size units.
handlelength float, default: rcParams[«legend.handlelength»] (default: 2.0 )
The length of the legend handles, in font-size units.
handleheight float, default: rcParams[«legend.handleheight»] (default: 0.7 )
The height of the legend handles, in font-size units.
handletextpad float, default: rcParams[«legend.handletextpad»] (default: 0.8 )
The pad between the legend handle and text, in font-size units.
borderaxespad float, default: rcParams[«legend.borderaxespad»] (default: 0.5 )
The pad between the axes and legend border, in font-size units.
columnspacing float, default: rcParams[«legend.columnspacing»] (default: 2.0 )
The spacing between columns, in font-size units.
handler_map dict 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 .
draggable bool, default: False
Whether the legend can be dragged with the mouse.
Some artists are not supported by this function. See Legend guide for details.
Examples using matplotlib.pyplot.legend #
© Copyright 2002–2012 John Hunter, Darren Dale, Eric Firing, Michael Droettboom and the Matplotlib development team; 2012–2023 The Matplotlib development team.
Built from v3.7.2-2-g4915f574b8.