CLN: backport mpl warning fix to 1.1.2 (#36155)

Author: fangchenli

doc/source/whatsnew/v1.1.2.rst

@@ -46,6 +46,7 @@ Bug fixes
 Other
 ~~~~~
 - :meth:`factorize` now supports ``na_sentinel=None`` to include NaN in the uniques of the values and remove ``dropna`` keyword which was unintentionally exposed to public facing API in 1.1 version from :meth:`factorize` (:issue:`35667`)
+- :meth:`DataFrame.plot` and meth:`Series.plot` raise ``UserWarning`` about usage of FixedFormatter and FixedLocator (:issue:`35684` and :issue:`35945`)
 
 .. ---------------------------------------------------------------------------
 

pandas/plotting/_matplotlib/core.py

@@ -1232,8 +1232,8 @@ def get_label(i):
         if self._need_to_set_index:
             xticks = ax.get_xticks()
             xticklabels = [get_label(x) for x in xticks]
-            ax.set_xticklabels(xticklabels)
             ax.xaxis.set_major_locator(FixedLocator(xticks))
+            ax.set_xticklabels(xticklabels)
 
         condition = (
             not self._use_dynamic_x()

pandas/tests/plotting/test_frame.py

@@ -2796,10 +2796,12 @@ def test_table(self):
         _check_plot_works(df.plot, table=True)
         _check_plot_works(df.plot, table=df)
 
-        ax = df.plot()
-        assert len(ax.tables) == 0
-        plotting.table(ax, df.T)
-        assert len(ax.tables) == 1
+        # GH 35945 UserWarning
+        with tm.assert_produces_warning(None):
+            ax = df.plot()
+            assert len(ax.tables) == 0
+            plotting.table(ax, df.T)
+            assert len(ax.tables) == 1
 
     def test_errorbar_scatter(self):
         df = DataFrame(np.random.randn(5, 2), index=range(5), columns=["x", "y"])