Add label parameter to pointplot (#3016)

* Add label parameter to pointplot

Unbreaks FacetGrid + pointplot (fixes #3004) and is generally useful.

* Update default kws in pointplot tests

* Update release notes

Author: mwaskom

doc/whatsnew/v0.12.1.rst

@@ -12,10 +12,12 @@ v0.12.1 (Unreleased)
 
 - |Enhancement| Marks that sort along the orient axis (e.g. :class:`Line`) now use a stable algorithm (:pr:`3064`).
 
-- |Fix| Make :class:`objects.PolyFit` robust to missing data (:pr:`3010`).
+- |Enhancement| |Fix| Add a `label` parameter to :func:`pointplot`, which addresses a regression in 0.12.0 when :func:`pointplot` is passed to :class:`FacetGrid` (:pr:`3016`).
 
 - |Fix| Fixed a bug that caused an exception when more than two layers with the same mappings were added (:pr:`3055`).
 
+- |Fix| Make :class:`objects.PolyFit` robust to missing data (:pr:`3010`).
+
 - |Fix| Fixed a regression in :func:`kdeplot` where passing `cmap` for an unfilled bivariate plot would raise an exception (:pr:`3065`).
 
 - |Build| Seaborn no longer contains doctest-style examples, simplifying the testing infrastructure (:pr:`3034`).

seaborn/categorical.py

@@ -1596,7 +1596,7 @@ class _PointPlotter(_CategoricalStatPlotter):
     def __init__(self, x, y, hue, data, order, hue_order,
                  estimator, errorbar, n_boot, units, seed,
                  markers, linestyles, dodge, join, scale,
-                 orient, color, palette, errwidth=None, capsize=None):
+                 orient, color, palette, errwidth, capsize, label):
         """Initialize the plotter."""
         self.establish_variables(x, y, hue, data, orient,
                                  order, hue_order, units)
@@ -1631,6 +1631,7 @@ def __init__(self, x, y, hue, data, order, hue_order,
         self.scale = scale
         self.errwidth = errwidth
         self.capsize = capsize
+        self.label = label
 
     @property
     def hue_offsets(self):
@@ -1678,7 +1679,7 @@ def draw_points(self, ax):
                 x, y = pointpos, self.statistic
             ax.scatter(x, y,
                        linewidth=mew, marker=marker, s=markersize,
-                       facecolor=colors, edgecolor=colors)
+                       facecolor=colors, edgecolor=colors, label=self.label)
 
         else:
 
@@ -2829,15 +2830,15 @@ def pointplot(
     estimator="mean", errorbar=("ci", 95), n_boot=1000, units=None, seed=None,
     markers="o", linestyles="-", dodge=False, join=True, scale=1,
     orient=None, color=None, palette=None, errwidth=None, ci="deprecated",
-    capsize=None, ax=None,
+    capsize=None, label=None, ax=None,
 ):
 
     errorbar = utils._deprecate_ci(errorbar, ci)
 
     plotter = _PointPlotter(x, y, hue, data, order, hue_order,
                             estimator, errorbar, n_boot, units, seed,
                             markers, linestyles, dodge, join, scale,
-                            orient, color, palette, errwidth, capsize)
+                            orient, color, palette, errwidth, capsize, label)
 
     if ax is None:
         ax = plt.gca()
@@ -2893,6 +2894,8 @@ def pointplot(
     {palette}
     {errwidth}
     {capsize}
+    label : string, optional
+        Label to represent the plot in a legend, only relevant when not using `hue`.
     {ax_in}
 
     Returns

tests/test_categorical.py

@@ -21,10 +21,12 @@
 
 from seaborn.external.version import Version
 from seaborn._oldcore import categorical_order
+from seaborn.axisgrid import FacetGrid
 from seaborn.categorical import (
     _CategoricalPlotterNew,
     Beeswarm,
     catplot,
+    pointplot,
     stripplot,
     swarmplot,
 )
@@ -2474,8 +2476,10 @@ class TestPointPlotter(CategoricalFixture):
         n_boot=100, units=None, seed=None,
         order=None, hue_order=None,
         markers="o", linestyles="-", dodge=0,
-        join=True, scale=1,
-        orient=None, color=None, palette=None,
+        join=True, scale=1, orient=None,
+        color=None, palette=None,
+        errwidth=None, capsize=None, label=None,
+
     )
 
     def test_different_defualt_colors(self):
@@ -2745,6 +2749,16 @@ def test_errorbar(self, long_df):
             expected = mean - 2 * sd, mean + 2 * sd
             assert_array_equal(line.get_ydata(), expected)
 
+    def test_on_facetgrid(self, long_df):
+
+        g = FacetGrid(long_df, hue="a")
+        g.map(pointplot, "a", "y")
+        g.add_legend()
+
+        order = categorical_order(long_df["a"])
+        legend_texts = [t.get_text() for t in g.legend.texts]
+        assert legend_texts == order
+
 
 class TestCountPlot(CategoricalFixture):