matplotlib
diff --git a/‎lib/matplotlib/cbook/__init__.py
Copy file name to clipboardExpand all lines: lib/matplotlib/cbook/__init__.py
+7-1Lines changed: 7 additions & 1 deletion b/‎lib/matplotlib/cbook/__init__.py
Copy file name to clipboardExpand all lines: lib/matplotlib/cbook/__init__.py
+7-1Lines changed: 7 additions & 1 deletion
diff --git a/‎lib/matplotlib/tests/test_axes.py
Copy file name to clipboardExpand all lines: lib/matplotlib/tests/test_axes.py
+6Lines changed: 6 additions & 0 deletions b/‎lib/matplotlib/tests/test_axes.py
Copy file name to clipboardExpand all lines: lib/matplotlib/tests/test_axes.py
+6Lines changed: 6 additions & 0 deletions
@@ -2061,7 +2061,13 @@ def _check_1d(x):
         return np.atleast_1d(x)
     else:
         try:
-            x[:, None]
+            ndim = x[:, None].ndim
+            # work around https://github.com/pandas-dev/pandas/issues/27775
+            # which mean the shape is not as expected. That this ever worked
+            # was an unintentional quirk of pandas the above line will raise
+            # an exception in the future.
+            if ndim < 2:
+                return np.atleast_1d(x)
             return x
         except (IndexError, TypeError):
             return np.atleast_1d(x)
 
@@ -5170,6 +5170,12 @@ def test_pandas_errorbar_indexing(pd):
     ax.errorbar('x', 'y', xerr='xe', yerr='ye', data=df)
 
 
+def test_pandas_index_shape(pd):
+    df = pd.DataFrame({"XX": [4, 5, 6], "YY": [7, 1, 2]})
+    fig, ax = plt.subplots()
+    ax.plot(df.index, df['YY'])
+
+
 def test_pandas_indexing_hist(pd):
     ser_1 = pd.Series(data=[1, 2, 2, 3, 3, 4, 4, 4, 4, 5])
     ser_2 = ser_1.iloc[1:]