update and fix docs

Author: saranti

doc/users/next_whats_new/boxplot_legend_support.rst

@@ -3,7 +3,7 @@ Legend support for Boxplot
 Boxplots now support a *label* parameter to create legend entries.
 
 Legend labels can be passed as a list of strings to label multiple boxes in a single
-boxplot call:
+`.boxplot` call:
 
 
 .. plot::
@@ -37,7 +37,7 @@ boxplot call:
     ax.legend()
 
 
-Or as a single string to each individual boxplot:
+Or as a single string to each individual `.boxplot`:
 
 .. plot::
     :include-source: true

lib/matplotlib/axes/_axes.py

@@ -3997,6 +3997,8 @@ def boxplot(self, x, notch=None, sym=None, vert=None, whis=None,
             median line (``result["medians"]``); if *patch_artist* is True, the legend
             will show the box `.Patch` artists (``result["boxes"]``) instead.
 
+            .. versionadded:: 3.9
+
         data : indexable object, optional
             DATA_PARAMETER_PLACEHOLDER
 
@@ -4221,6 +4223,8 @@ def bxp(self, bxpstats, positions=None, widths=None, vert=True,
             median line (``result["medians"]``); if *patch_artist* is True, the legend
             will show the box `.Patch` artists (``result["boxes"]``) instead.
 
+            .. versionadded:: 3.9
+
         zorder : float, default: ``Line2D.zorder = 2``
           The zorder of the resulting boxplot.
 
@@ -4421,8 +4425,7 @@ def do_patch(xs, ys, **kwargs):
                 box_or_med[0].set_label(label)
             else:  # label is a sequence
                 if len(box_or_med) != len(label):
-                    raise ValueError("There must be an equal number of legend"
-                                     " labels and boxplots.")
+                    raise ValueError(datashape_message.format("label"))
                 for artist, lbl in zip(box_or_med, label):
                     artist.set_label(lbl)
 

lib/matplotlib/axes/_axes.pyi

@@ -372,7 +372,7 @@ class Axes(_AxesBase):
         autorange: bool = ...,
         zorder: float | None = ...,
         capwidths: float | ArrayLike | None = ...,
-		label: Sequence[str] | None = ...,
+        label: Sequence[str] | None = ...,
         *,
         data=...,
     ) -> dict[str, Any]: ...
@@ -398,7 +398,7 @@ class Axes(_AxesBase):
         manage_ticks: bool = ...,
         zorder: float | None = ...,
         capwidths: float | ArrayLike | None = ...,
-		label: Sequence[str] | None = ...,
+        label: Sequence[str] | None = ...,
     ) -> dict[str, Any]: ...
     def scatter(
         self,