Axes.stem docstring document orientation as literals (#24807)

ksunden · timhoffm · QuLogic · web-flow · commit ab364af5a383 · 2022-12-22T08:48:58.000+01:00
* Axes.stem docstring document orientation as literals

We use `_api.check_in_list` in the method body, so arbitrary strings are
not accetable and will raise if it is not precisely "vertical" or
"horizontal".

This brings the docstring in line with this behavior.
Many other places which have an orientation kwarg are similarly
documented.


Co-authored-by: Tim Hoffmann &lt;2836374+timhoffm@users.noreply.github.com&gt;
Co-authored-by: Elliott Sales de Andrade &lt;quantum.analyst@gmail.com&gt;
diff --git a/lib/matplotlib/axes/_axes.py b/lib/matplotlib/axes/_axes.py
@@ -2946,9 +2946,9 @@ def stem(self, *args, linefmt=None, markerfmt=None, basefmt=None, bottom=0,
         basefmt : str, default: 'C3-' ('C2-' in classic mode)
             A format string defining the properties of the baseline.
 
-        orientation : str, default: 'vertical'
+        orientation : {'vertical', 'horizontal'}, default: 'vertical'
             If 'vertical', will produce a plot with stems oriented vertically,
-            otherwise the stems will be oriented horizontally.
+            If 'horizontal', the stems will be oriented horizontally.
 
         bottom : float, default: 0
             The y/x-position of the baseline (depending on orientation).
