move rcparam setting to bxp & fix test

lib/matplotlib/axes/_axes.py

@@ -3878,7 +3878,7 @@ def boxplot(self, x, notch=None, sym=None, vert=None,
             the fliers.  If `None`, then the fliers default to 'b+'.  More
             control is provided by the *flierprops* parameter.
 
-        vert : bool, default: :rc:`boxplot.vertical`
+        vert : bool, optional
             .. deprecated:: 3.10
                 Use *orientation* instead.
 
@@ -4060,8 +4060,6 @@ def boxplot(self, x, notch=None, sym=None, vert=None,
                                        labels=tick_labels, autorange=autorange)
         if notch is None:
             notch = mpl.rcParams['boxplot.notch']
-        if vert is None:
-            vert = mpl.rcParams['boxplot.vertical']
         if patch_artist is None:
             patch_artist = mpl.rcParams['boxplot.patchartist']
         if meanline is None:
@@ -4227,7 +4225,7 @@ def bxp(self, bxpstats, positions=None, widths=None, vert=None,
             Either a scalar or a vector and sets the width of each cap.
             The default is ``0.5*(width of the box)``, see *widths*.
 
-        vert : bool, default: True
+        vert : bool, optional
             .. deprecated:: 3.10
                 Use *orientation* instead.
 
@@ -4303,6 +4301,7 @@ def bxp(self, bxpstats, positions=None, widths=None, vert=None,
         --------
         boxplot : Draw a boxplot from data instead of pre-computed statistics.
         """
+
         # Clamp median line to edge of box by default.
         medianprops = {
             "solid_capstyle": "butt",
@@ -4361,14 +4360,17 @@ def merge_kw_rc(subkey, explicit, zdelta=0, usemarker=True):
             mean_kw[removed_prop] = ''
 
         # vert and orientation parameters are linked until vert's
-        # deprecation period expires. vert only takes precedence and
-        # raises a deprecation warning if set to False.
-        if vert is False:
+        # deprecation period expires. vert only takes precedence
+        # if set to False.
+        if vert is None:
+            vert = mpl.rcParams['boxplot.vertical']
+        else:
             _api.warn_deprecated(
                 "3.10",
                 name="vert: bool",
                 alternative="orientation: {'vertical', 'horizontal'}"
-                )
+            )
+        if vert is False:
             orientation = 'horizontal'
         _api.check_in_list(['horizontal', 'vertical'], orientation=orientation)
 

lib/matplotlib/tests/test_axes.py

@@ -3155,7 +3155,7 @@ def _bxp_test_helper(
     logstats = mpl.cbook.boxplot_stats(
         np.random.lognormal(mean=1.25, sigma=1., size=(37, 4)), **stats_kwargs)
     fig, ax = plt.subplots()
-    if not bxp_kwargs.get('orientation') or bxp_kwargs.get('orientation') == 'vertical':
+    if bxp_kwargs.get('orientation', 'vertical') == 'vertical':
         ax.set_yscale('log')
     else:
         ax.set_xscale('log')