ENH: add long_axis property to colorbar

TST: check long axis correct

Author: jklymak

lib/matplotlib/colorbar.py

@@ -430,6 +430,11 @@ def __init__(self, ax, mappable=None, *, cmap=None,
         self._extend_cid2 = self.ax.callbacks.connect(
             "ylim_changed", self._do_extends)
 
+    @property
+    def long_axis(self):
+        """Axis that has decorations (ticks etc) on it."""
+        return self._long_axis()
+
     @property
     def locator(self):
         """Major tick `.Locator` for the colorbar."""

lib/matplotlib/tests/test_colorbar.py

@@ -1139,6 +1139,7 @@ def test_colorbar_set_formatter_locator():
     fmt = LogFormatter()
     cb.minorformatter = fmt
     assert cb.ax.yaxis.get_minor_formatter() is fmt
+    assert cb.long_axis is cb.ax.yaxis
 
 
 @image_comparison(['colorbar_extend_alpha.png'], remove_text=True,