Skip to content

Reverse legend #24759

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 15 commits into from
Dec 25, 2022
Merged

Reverse legend #24759

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
15 commits
Select commit Hold shift + click to select a range
a94ecc5
Legend: Include reverse parameter and if cond
Marvvxi Dec 17, 2022
cda9334
Legend: Bugfix comma
Marvvxi Dec 17, 2022
cb52fee
Legend: Code style
Marvvxi Dec 17, 2022
75d9849
Legend: Linting/flake8
Marvvxi Dec 17, 2022
a67ee8a
Legend: missed whitespace after ','
Marvvxi Dec 17, 2022
5633cdf
Legend: remove reverse from init_legend_box
Marvvxi Dec 18, 2022
8964e8a
Legend: Add test for reverse option
Marvvxi Dec 19, 2022
b9f19e1
Legend: Add docstring
Marvvxi Dec 19, 2022
704184b
Update lib/matplotlib/tests/test_legend.py
Marvvxi Dec 20, 2022
fad4e44
Legend: include markers test
Marvvxi Dec 20, 2022
2a5ed70
Legend: Remove x,y list increase readability
Marvvxi Dec 20, 2022
74c5d44
Update lib/matplotlib/legend.py
Marvvxi Dec 22, 2022
3723815
Add a what's new entry for legend(..., reverse=True)
timhoffm Dec 22, 2022
fdb5214
Add a test for checking the displayed legend is reversed
timhoffm Dec 22, 2022
15911a6
Added .. versionadded tag to reverse parameter
timhoffm Dec 22, 2022
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
4 changes: 4 additions & 0 deletions doc/users/next_whats_new/reverse_legend.rst
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,4 @@
Reversed order of legend entries
Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Suggested change
Reversed order of legend entries
Reverse order of legend entries

--------------------------------
The order of legend entries can now be reversed by passing ``reverse=True`` to
`~.Axes.legend`.
Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Not sure if it's overkill to have a teeny example here, something like

fig, (ax1, ax2) = plt.subplots(ncols=2, figsize=(4,2))

for ax in [ax1, ax2]:
    ax.axhline(.25, label="25")
    ax.axhline(.75, label="75")

ax1.legend()
ax2.legend(reverse=True)

11 changes: 11 additions & 0 deletions lib/matplotlib/legend.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -209,6 +209,12 @@ def _update_bbox_to_anchor(self, loc_in_canvas):
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.

Comment on lines +212 to +215
Copy link
Member

@story645 story645 Dec 22, 2022 •
edited
Loading

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Forgot, but based on @tacaswell comment this should also get a version added at the end (skip a line) so like:

    ..versionadded:: 3.7

https://matplotlib.org/devdocs/devel/coding_guide.html#new-features-and-api-changes

..versionadded:: 3.7

frameon : bool, default: :rc:`legend.frameon`
Whether the legend should be drawn on a patch (frame).

Expand Down Expand Up @@ -312,6 +318,7 @@ def __init__(
numpoints=None, # number of points in the legend line
markerscale=None, # relative size of legend markers vs. original
markerfirst=True, # left/right ordering of legend marker and label
reverse=False, # reverse ordering of legend marker and label
Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Please add a docstring as well. This should go in line 212 (we do a bit of docstring processing that is why the docstring text is in a separate place).

scatterpoints=None, # number of scatter points
scatteryoffsets=None,
prop=None, # properties for the legend texts
Expand Down Expand Up @@ -437,6 +444,10 @@ def val_or_rc(val, rc_name):
_hand.append(handle)
labels, handles = _lab, _hand

if reverse:
labels.reverse()
handles.reverse()

handles = list(handles)
Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Suggested change
handles = list(handles)

if len(handles) < 2:
ncols = 1
Expand Down
32 changes: 32 additions & 0 deletions lib/matplotlib/tests/test_legend.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -294,6 +294,38 @@ def test_legend_remove():
assert ax.get_legend() is None


def test_reverse_legend_handles_and_labels():
"""Check that the legend handles and labels are reversed."""
fig, ax = plt.subplots()
x = 1
y = 1
labels = ["First label", "Second label", "Third label"]
markers = ['.', ',', 'o']

ax.plot(x, y, markers[0], label=labels[0])
ax.plot(x, y, markers[1], label=labels[1])
ax.plot(x, y, markers[2], label=labels[2])
leg = ax.legend(reverse=True)
actual_labels = [t.get_text() for t in leg.get_texts()]
actual_markers = [h.get_marker() for h in leg.legend_handles]
assert actual_labels == list(reversed(labels))
assert actual_markers == list(reversed(markers))


@check_figures_equal(extensions=["png"])
def test_reverse_legend_display(fig_test, fig_ref):
"""Check that the rendered legend entries are reversed"""
ax = fig_test.subplots()
ax.plot([1], 'ro', label="first")
ax.plot([2], 'bx', label="second")
ax.legend(reverse=True)

ax = fig_ref.subplots()
ax.plot([2], 'bx', label="second")
ax.plot([1], 'ro', label="first")
ax.legend()


class TestLegendFunction:
# Tests the legend function on the Axes and pyplot.
def test_legend_no_args(self):
Expand Down