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<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"

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<h1>Source code for matplotlib.legend</h1><div class="highlight"><pre>

"""

The legend module defines the Legend class, which is responsible for

drawing legends associated with axes and/or figures.

.. important::

It is unlikely that you would ever create a Legend instance manually.

Most users would normally create a legend via the

:meth:`~matplotlib.axes.Axes.legend` function. For more details on legends

there is also a :ref:`legend guide

<sphx_glr_tutorials_intermediate_legend_guide.py>`.

The Legend class can be considered as a container of legend handles

and legend texts. Creation of corresponding legend handles from the

plot elements in the axes or figures (e.g., lines, patches, etc.) are

specified by the handler map, which defines the mapping between the

plot elements and the legend handlers to be used (the default legend

handlers are defined in the :mod:`~matplotlib.legend_handler` module).

Note that not all kinds of artist are supported by the legend yet by default

but it is possible to extend the legend handler's capabilities to support

arbitrary objects. See the :ref:`legend guide

<sphx_glr_tutorials_intermediate_legend_guide.py>` for more information.

"""

from __future__ import (absolute_import, division, print_function,

unicode_literals)

import six

import logging

import warnings

import numpy as np

from matplotlib import rcParams

from matplotlib import docstring

from matplotlib.artist import Artist, allow_rasterization

from matplotlib.cbook import silent_list, is_hashable

import matplotlib.colors as colors

from matplotlib.font_manager import FontProperties

from matplotlib.lines import Line2D

from matplotlib.patches import Patch, Rectangle, Shadow, FancyBboxPatch

from matplotlib.collections import (LineCollection, RegularPolyCollection,

CircleCollection, PathCollection,

PolyCollection)

from matplotlib.transforms import Bbox, BboxBase, TransformedBbox

from matplotlib.transforms import BboxTransformTo, BboxTransformFrom

from matplotlib.offsetbox import HPacker, VPacker, TextArea, DrawingArea

from matplotlib.offsetbox import DraggableOffsetBox

from matplotlib.container import ErrorbarContainer, BarContainer, StemContainer

from . import legend_handler

<div class="viewcode-block" id="DraggableLegend"><a class="viewcode-back" href="../../api/legend_api.html#matplotlib.legend.DraggableLegend">[docs]</a>class DraggableLegend(DraggableOffsetBox):

def __init__(self, legend, use_blit=False, update="loc"):

"""

Parameters

----------

update : string

If "loc", update *loc* parameter of legend upon finalizing.

If "bbox", update *bbox_to_anchor* parameter.

"""

self.legend = legend

if update in ["loc", "bbox"]:

self._update = update

else:

raise ValueError("update parameter '%s' is not supported." %

update)

DraggableOffsetBox.__init__(self, legend, legend._legend_box,

use_blit=use_blit)

<div class="viewcode-block" id="DraggableLegend.artist_picker"><a class="viewcode-back" href="../../api/legend_api.html#matplotlib.legend.DraggableLegend.artist_picker">[docs]</a> def artist_picker(self, legend, evt):

return self.legend.contains(evt)</div>

<div class="viewcode-block" id="DraggableLegend.finalize_offset"><a class="viewcode-back" href="../../api/legend_api.html#matplotlib.legend.DraggableLegend.finalize_offset">[docs]</a> def finalize_offset(self):

loc_in_canvas = self.get_loc_in_canvas()

if self._update == "loc":

self._update_loc(loc_in_canvas)

elif self._update == "bbox":

self._update_bbox_to_anchor(loc_in_canvas)

else:

raise RuntimeError("update parameter '%s' is not supported." %

self.update)</div>

def _update_loc(self, loc_in_canvas):

bbox = self.legend.get_bbox_to_anchor()

# if bbox has zero width or height, the transformation is

# ill-defined. Fall back to the defaul bbox_to_anchor.

if bbox.width == 0 or bbox.height == 0:

self.legend.set_bbox_to_anchor(None)

_bbox_transform = BboxTransformFrom(bbox)

self.legend._loc = tuple(

_bbox_transform.transform_point(loc_in_canvas)

)

def _update_bbox_to_anchor(self, loc_in_canvas):

tr = self.legend.axes.transAxes

loc_in_bbox = tr.transform_point(loc_in_canvas)

_legend_kw_doc = '''

loc : int or string or pair of floats, default: 'upper right'

The location of the legend. Possible codes are:

=============== =============

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

=============== =============

Alternatively can be a 2-tuple giving ``x, y`` of the lower-left

corner of the legend in axes coordinates (in which case

``bbox_to_anchor`` will be ignored).

bbox_to_anchor : `.BboxBase` or pair of floats

Specify any arbitrary location for the legend in `bbox_transform`

coordinates (default Axes coordinates).

For example, to put the legend's upper right hand corner in the

center of the axes the following keywords can be used::

loc='upper right', bbox_to_anchor=(0.5, 0.5)

ncol : integer

The number of columns that the legend has. Default is 1.

prop : None or :class:`matplotlib.font_manager.FontProperties` or dict

The font properties of the legend. If None (default), the current

:data:`matplotlib.rcParams` will be used.

fontsize : int or float or {'xx-small', 'x-small', 'small', 'medium', \

'large', 'x-large', 'xx-large'}

Controls 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.

numpoints : None or int

The number of marker points in the legend when creating a legend

entry for a `.Line2D` (line).

Default is ``None``, which will take the value from

:rc:`legend.numpoints`.

scatterpoints : None or int

The number of marker points in the legend when creating

a legend entry for a `.PathCollection` (scatter plot).

Default is ``None``, which will take the value from

:rc:`legend.scatterpoints`.

scatteryoffsets : iterable of floats

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]``. Default is ``[0.375, 0.5, 0.3125]``.

markerscale : None or int or float

The relative size of legend markers compared with the originally

drawn ones.

Default is ``None``, which will take the value from

:rc:`legend.markerscale`.

markerfirst : bool

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.

Default is *True*.

frameon : None or bool

Control whether the legend should be drawn on a patch

(frame).

Default is ``None``, which will take the value from

:rc:`legend.frameon`.

fancybox : None or bool

Control whether round edges should be enabled around the

:class:`~matplotlib.patches.FancyBboxPatch` which makes up the

legend's background.

Default is ``None``, which will take the value from

:rc:`legend.fancybox`.

shadow : None or bool

Control whether to draw a shadow behind the legend.

Default is ``None``, which will take the value from

:rc:`legend.shadow`.

framealpha : None or float

Control the alpha transparency of the legend's background.

Default is ``None``, which will take the value from

:rc:`legend.framealpha`. If shadow is activated and

*framealpha* is ``None``, the default value is ignored.

facecolor : None or "inherit" or a color spec

Control the legend's background color.

Default is ``None``, which will take the value from

:rc:`legend.facecolor`. If ``"inherit"``, it will take

:rc:`axes.facecolor`.

edgecolor : None or "inherit" or a color spec

Control the legend's background patch edge color.

Default is ``None``, which will take the value from

:rc:`legend.edgecolor` If ``"inherit"``, it will take

:rc:`axes.edgecolor`.

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_transform : None or :class:`matplotlib.transforms.Transform`

The transform for the bounding box (`bbox_to_anchor`). For a value

of ``None`` (default) the Axes'

:data:`~matplotlib.axes.Axes.transAxes` transform will be used.

title : str or None

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

borderpad : float or None

The fractional whitespace inside the legend border.

Measured in font-size units.

Default is ``None``, which will take the value from

:rc:`legend.borderpad`.

labelspacing : float or None

The vertical space between the legend entries.

Measured in font-size units.

Default is ``None``, which will take the value from

:rc:`legend.labelspacing`.

handlelength : float or None

The length of the legend handles.

Measured in font-size units.

Default is ``None``, which will take the value from

:rc:`legend.handlelength`.

handletextpad : float or None

The pad between the legend handle and text.

Measured in font-size units.

Default is ``None``, which will take the value from

:rc:`legend.handletextpad`.

borderaxespad : float or None

The pad between the axes and legend border.

Measured in font-size units.

Default is ``None``, which will take the value from

:rc:`legend.borderaxespad`.

columnspacing : float or None

The spacing between columns.

Measured in font-size units.

Default is ``None``, which will take the value from

:rc:`legend.columnspacing`.

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 :func:`matplotlib.legend.Legend.get_legend_handler_map`.

'''

docstring.interpd.update(_legend_kw_doc=_legend_kw_doc)

<div class="viewcode-block" id="Legend"><a class="viewcode-back" href="../../api/legend_api.html#matplotlib.legend.Legend">[docs]</a>class Legend(Artist):

"""

Place a legend on the axes at location loc.

"""

codes = {'best': 0, # only implemented for axes legends

'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,

}

zorder = 5

def __str__(self):

return "Legend"

@docstring.dedent_interpd

def __init__(self, parent, handles, labels,

loc=None,

numpoints=None, # the number of points in the legend line

markerscale=None, # the relative size of legend markers

# vs. original

markerfirst=True, # controls ordering (left-to-right) of

# legend marker and label

scatterpoints=None, # number of scatter points

scatteryoffsets=None,

prop=None, # properties for the legend texts

fontsize=None, # keyword to set font size directly

# spacing & pad defined as a fraction of the font-size

borderpad=None, # the whitespace inside the legend border

labelspacing=None, # the vertical space between the legend

# entries

handlelength=None, # the length of the legend handles

handleheight=None, # the height of the legend handles

handletextpad=None, # the pad between the legend handle

# and text

borderaxespad=None, # the pad between the axes and legend

# border

columnspacing=None, # spacing between columns

ncol=1, # number of columns

mode=None, # mode for horizontal distribution of columns.

# None, "expand"

fancybox=None, # True use a fancy box, false use a rounded

# box, none use rc

shadow=None,

title=None, # set a title for the legend

framealpha=None, # set frame alpha

edgecolor=None, # frame patch edgecolor

facecolor=None, # frame patch facecolor

bbox_to_anchor=None, # bbox that the legend will be anchored.

bbox_transform=None, # transform for the bbox

frameon=None, # draw frame

handler_map=None,

):

"""

Parameters

----------

parent : `.Axes` or `.Figure`

The artist that contains the legend.

handles : sequence of `.Artist`

A list of Artists (lines, patches) to be added to the legend.

labels : sequence of strings

A list of labels to show next to the artists. The length of handles

and labels should be the same. If they are not, they are truncated

to the smaller of both lengths.

Other Parameters

----------------

loc : int or string or pair of floats, default: 'upper right'

The location of the legend. Possible codes are:

=============== =============

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

=============== =============

Alternatively can be a 2-tuple giving ``x, y`` of the lower-left

corner of the legend in axes coordinates (in which case

``bbox_to_anchor`` will be ignored).

bbox_to_anchor : `.BboxBase` or pair of floats

Specify any arbitrary location for the legend in `bbox_transform`

coordinates (default Axes coordinates).

For example, to put the legend's upper right hand corner in the

center of the axes the following keywords can be used::

loc='upper right', bbox_to_anchor=(0.5, 0.5)

ncol : integer

The number of columns that the legend has. Default is 1.

prop : None or :class:`matplotlib.font_manager.FontProperties` or dict

The font properties of the legend. If None (default), the current

:data:`matplotlib.rcParams` will be used.

fontsize : int or float or {'xx-small', 'x-small', 'small', 'medium', \

'large', 'x-large', 'xx-large'}

Controls 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.

numpoints : None or int

The number of marker points in the legend when creating a legend

entry for a `.Line2D` (line).

Default is ``None``, which will take the value from

:rc:`legend.numpoints`.

scatterpoints : None or int

The number of marker points in the legend when creating

a legend entry for a `.PathCollection` (scatter plot).

Default is ``None``, which will take the value from

:rc:`legend.scatterpoints`.

scatteryoffsets : iterable of floats

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]``. Default is ``[0.375, 0.5, 0.3125]``.

markerscale : None or int or float

The relative size of legend markers compared with the originally

drawn ones.

Default is ``None``, which will take the value from

:rc:`legend.markerscale`.

markerfirst : bool

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.

Default is *True*.

frameon : None or bool

Control whether the legend should be drawn on a patch

(frame).

Default is ``None``, which will take the value from

:rc:`legend.frameon`.

fancybox : None or bool

Control whether round edges should be enabled around the

:class:`~matplotlib.patches.FancyBboxPatch` which makes up the

legend's background.

Default is ``None``, which will take the value from

:rc:`legend.fancybox`.

shadow : None or bool

Control whether to draw a shadow behind the legend.

Default is ``None``, which will take the value from

:rc:`legend.shadow`.

framealpha : None or float

Control the alpha transparency of the legend's background.

Default is ``None``, which will take the value from

:rc:`legend.framealpha`. If shadow is activated and

*framealpha* is ``None``, the default value is ignored.

facecolor : None or "inherit" or a color spec

Control the legend's background color.

Default is ``None``, which will take the value from

:rc:`legend.facecolor`. If ``"inherit"``, it will take

:rc:`axes.facecolor`.

edgecolor : None or "inherit" or a color spec

Control the legend's background patch edge color.

Default is ``None``, which will take the value from

:rc:`legend.edgecolor` If ``"inherit"``, it will take

:rc:`axes.edgecolor`.

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_transform : None or :class:`matplotlib.transforms.Transform`

The transform for the bounding box (`bbox_to_anchor`). For a value

of ``None`` (default) the Axes'

:data:`~matplotlib.axes.Axes.transAxes` transform will be used.

title : str or None

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

borderpad : float or None

The fractional whitespace inside the legend border.

Measured in font-size units.

Default is ``None``, which will take the value from

:rc:`legend.borderpad`.

labelspacing : float or None

The vertical space between the legend entries.

Measured in font-size units.

Default is ``None``, which will take the value from

:rc:`legend.labelspacing`.

handlelength : float or None

The length of the legend handles.

Measured in font-size units.

Default is ``None``, which will take the value from

:rc:`legend.handlelength`.

handletextpad : float or None

The pad between the legend handle and text.

Measured in font-size units.

Default is ``None``, which will take the value from

:rc:`legend.handletextpad`.

borderaxespad : float or None

The pad between the axes and legend border.

Measured in font-size units.

Default is ``None``, which will take the value from

:rc:`legend.borderaxespad`.

columnspacing : float or None

The spacing between columns.

Measured in font-size units.

Default is ``None``, which will take the value from

:rc:`legend.columnspacing`.

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 :func:`matplotlib.legend.Legend.get_legend_handler_map`.

Notes

-----

Users can specify any arbitrary location for the legend using the

*bbox_to_anchor* keyword argument. bbox_to_anchor can be an instance

of BboxBase(or its derivatives) or a tuple of 2 or 4 floats.

See :meth:`set_bbox_to_anchor` for more detail.

The legend location can be specified by setting *loc* with a tuple of

2 floats, which is interpreted as the lower-left corner of the legend

in the normalized axes coordinate.

"""

# local import only to avoid circularity

from matplotlib.axes import Axes

from matplotlib.figure import Figure

Artist.__init__(self)

if prop is None:

if fontsize is not None:

self.prop = FontProperties(size=fontsize)

else:

elif isinstance(prop, dict):

self.prop = FontProperties(**prop)

if "size" not in prop:

self.prop.set_size(rcParams["legend.fontsize"])

else:

self.prop = prop

self._fontsize = self.prop.get_size_in_points()

self.texts = []

self.legendHandles = []

self._legend_title_box = None

#: A dictionary with the extra handler mappings for this Legend

#: instance.

self._custom_handler_map = handler_map

locals_view = locals()

for name in ["numpoints", "markerscale", "shadow", "columnspacing",

"scatterpoints", "handleheight", 'borderpad',

'labelspacing', 'handlelength', 'handletextpad',

'borderaxespad']:

if locals_view[name] is None:

value = rcParams["legend." + name]

else:

value = locals_view[name]

setattr(self, name, value)

del locals_view

# trim handles and labels if illegal label...

_lab, _hand = [], []

for label, handle in zip(labels, handles):

if (isinstance(label, six.string_types) and

label.startswith('_')):

warnings.warn('The handle {!r} has a label of {!r} which '

'cannot be automatically added to the '

'legend.'.format(handle, label))

else:

_lab.append(label)

_hand.append(handle)

labels, handles = _lab, _hand

handles = list(handles)

if len(handles) < 2:

ncol = 1

self._ncol = ncol

if self.numpoints <= 0:

raise ValueError("numpoints must be > 0; it was %d" % numpoints)

# introduce y-offset for handles of the scatter plot

if scatteryoffsets is None:

self._scatteryoffsets = np.array([3. / 8., 4. / 8., 2.5 / 8.])

else:

reps = self.scatterpoints // len(self._scatteryoffsets) + 1

reps)[:self.scatterpoints]

# _legend_box is an OffsetBox instance that contains all

# legend items and will be initialized from _init_legend_box()

# method.

self._legend_box = None

if isinstance(parent, Axes):

self.isaxes = True

self.axes = parent

self.set_figure(parent.figure)

elif isinstance(parent, Figure):

self.isaxes = False

self.set_figure(parent)

else:

raise TypeError("Legend needs either Axes or Figure as parent")

self.parent = parent

if loc is None:

loc = rcParams["legend.loc"]

if not self.isaxes and loc in [0, 'best']:

loc = 'upper right'

if isinstance(loc, six.string_types):

if loc not in self.codes:

if self.isaxes:

warnings.warn('Unrecognized location "%s". Falling back '

'on "best"; valid locations are\n\t%s\n'

% (loc, '\n\t'.join(self.codes)))

loc = 0

else:

'on "upper right"; '

'valid locations are\n\t%s\n'

loc = 1

else:

loc = self.codes[loc]

if not self.isaxes and loc == 0:

warnings.warn('Automatic legend placement (loc="best") not '

'implemented for figure legend. '

'Falling back on "upper right".')

loc = 1

self._mode = mode

self.set_bbox_to_anchor(bbox_to_anchor, bbox_transform)

# We use FancyBboxPatch to draw a legend frame. The location

# and size of the box will be updated during the drawing time.

if facecolor is None:

facecolor = rcParams["legend.facecolor"]

if facecolor == 'inherit':

facecolor = rcParams["axes.facecolor"]

if edgecolor is None:

edgecolor = rcParams["legend.edgecolor"]

if edgecolor == 'inherit':

edgecolor = rcParams["axes.edgecolor"]

self.legendPatch = FancyBboxPatch(

xy=(0.0, 0.0), width=1., height=1.,

facecolor=facecolor,

edgecolor=edgecolor,

mutation_scale=self._fontsize,

snap=True

)

# The width and height of the legendPatch will be set (in the

# draw()) to the length that includes the padding. Thus we set

# pad=0 here.

if fancybox is None:

fancybox = rcParams["legend.fancybox"]

if fancybox:

self.legendPatch.set_boxstyle("round", pad=0,

rounding_size=0.2)

else:

self.legendPatch.set_boxstyle("square", pad=0)

self._set_artist_props(self.legendPatch)

self._drawFrame = frameon

if frameon is None:

self._drawFrame = rcParams["legend.frameon"]

# init with null renderer

self._init_legend_box(handles, labels, markerfirst)

# If shadow is activated use framealpha if not

# explicitly passed. See Issue 8943

if framealpha is None:

if shadow:

self.get_frame().set_alpha(1)

else:

self._loc = loc

self.set_title(title)

self._last_fontsize_points = self._fontsize

self._draggable = None

def _set_artist_props(self, a):

"""

Set the boilerplate props for artists added to axes.

"""

a.set_figure(self.figure)

if self.isaxes:

# a.set_axes(self.axes)

a.axes = self.axes

a.set_transform(self.get_transform())

def _set_loc(self, loc):

# find_offset function will be provided to _legend_box and

# _legend_box will draw itself at the location of the return

# value of the find_offset.

self._loc_real = loc

self.stale = True

self._legend_box.set_offset(self._findoffset)

def _get_loc(self):

return self._loc_real

_loc = property(_get_loc, _set_loc)

def _findoffset(self, width, height, xdescent, ydescent, renderer):

"Helper function to locate the legend."

if self._loc == 0: # "best".

x, y = self._find_best_position(width, height, renderer)

elif self._loc in Legend.codes.values(): # Fixed location.

bbox = Bbox.from_bounds(0, 0, width, height)

x, y = self._get_anchored_bbox(self._loc, bbox,

self.get_bbox_to_anchor(),

renderer)

else: # Axes or figure coordinates.

fx, fy = self._loc

bbox = self.get_bbox_to_anchor()

x, y = bbox.x0 + bbox.width * fx, bbox.y0 + bbox.height * fy

return x + xdescent, y + ydescent

<div class="viewcode-block" id="Legend.draw"><a class="viewcode-back" href="../../api/legend_api.html#matplotlib.legend.Legend.draw">[docs]</a> @allow_rasterization

def draw(self, renderer):

"Draw everything that belongs to the legend."

if not self.get_visible():

return

renderer.open_group('legend')

fontsize = renderer.points_to_pixels(self._fontsize)

# if mode == fill, set the width of the legend_box to the

# width of the paret (minus pads)

if self._mode in ["expand"]:

pad = 2 * (self.borderaxespad + self.borderpad) * fontsize

self._legend_box.set_width(self.get_bbox_to_anchor().width - pad)

# update the location and size of the legend. This needs to

# be done in any case to clip the figure right.

bbox = self._legend_box.get_window_extent(renderer)

self.legendPatch.set_bounds(bbox.x0, bbox.y0,

bbox.width, bbox.height)

self.legendPatch.set_mutation_scale(fontsize)

if self._drawFrame:

if self.shadow:

shadow = Shadow(self.legendPatch, 2, -2)

shadow.draw(renderer)

self.legendPatch.draw(renderer)

self._legend_box.draw(renderer)

renderer.close_group('legend')

self.stale = False</div>

def _approx_text_height(self, renderer=None):

"""

Return the approximate height of the text. This is used to place

the legend handle.

"""

if renderer is None:

return self._fontsize

else:

return renderer.points_to_pixels(self._fontsize)

# _default_handler_map defines the default mapping between plot

# elements and the legend handlers.

_default_handler_map = {

StemContainer: legend_handler.HandlerStem(),

ErrorbarContainer: legend_handler.HandlerErrorbar(),

Line2D: legend_handler.HandlerLine2D(),

Patch: legend_handler.HandlerPatch(),

LineCollection: legend_handler.HandlerLineCollection(),

RegularPolyCollection: legend_handler.HandlerRegularPolyCollection(),

CircleCollection: legend_handler.HandlerCircleCollection(),

BarContainer: legend_handler.HandlerPatch(

update_func=legend_handler.update_from_first_child),

tuple: legend_handler.HandlerTuple(),

PathCollection: legend_handler.HandlerPathCollection(),

PolyCollection: legend_handler.HandlerPolyCollection()

}

# (get|set|update)_default_handler_maps are public interfaces to

# modify the default handler map.

<div class="viewcode-block" id="Legend.get_default_handler_map"><a class="viewcode-back" href="../../api/legend_api.html#matplotlib.legend.Legend.get_default_handler_map">[docs]</a> @classmethod

def get_default_handler_map(cls):

"""

A class method that returns the default handler map.

"""

return cls._default_handler_map</div>

<div class="viewcode-block" id="Legend.set_default_handler_map"><a class="viewcode-back" href="../../api/legend_api.html#matplotlib.legend.Legend.set_default_handler_map">[docs]</a> @classmethod

def set_default_handler_map(cls, handler_map):

"""

A class method to set the default handler map.

"""

cls._default_handler_map = handler_map</div>

<div class="viewcode-block" id="Legend.update_default_handler_map"><a class="viewcode-back" href="../../api/legend_api.html#matplotlib.legend.Legend.update_default_handler_map">[docs]</a> @classmethod

def update_default_handler_map(cls, handler_map):

"""

A class method to update the default handler map.

"""

cls._default_handler_map.update(handler_map)</div>

<div class="viewcode-block" id="Legend.get_legend_handler_map"><a class="viewcode-back" href="../../api/legend_api.html#matplotlib.legend.Legend.get_legend_handler_map">[docs]</a> def get_legend_handler_map(self):

"""

Return the handler map.

"""

default_handler_map = self.get_default_handler_map()

if self._custom_handler_map:

hm = default_handler_map.copy()

hm.update(self._custom_handler_map)

return hm

else:

return default_handler_map</div>

<div class="viewcode-block" id="Legend.get_legend_handler"><a class="viewcode-back" href="../../api/legend_api.html#matplotlib.legend.Legend.get_legend_handler">[docs]</a> @staticmethod

def get_legend_handler(legend_handler_map, orig_handle):

"""

Return a legend handler from *legend_handler_map* that

corresponds to *orig_handler*.

*legend_handler_map* should be a dictionary object (that is

returned by the get_legend_handler_map method).

It first checks if the *orig_handle* itself is a key in the

*legend_hanler_map* and return the associated value.

Otherwise, it checks for each of the classes in its

method-resolution-order. If no matching key is found, it

returns ``None``.

"""

if is_hashable(orig_handle):

try:

return legend_handler_map[orig_handle]

except KeyError:

pass

for handle_type in type(orig_handle).mro():

try:

return legend_handler_map[handle_type]

except KeyError:

pass

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