FIX: indexed pandas bar

Author: jklymak

lib/matplotlib/axes/_axes.py

@@ -2140,12 +2140,31 @@ def _convert_dx(dx, x0, xconv, convert):
             try:
                 x0 = x0[0]
             except (TypeError, IndexError, KeyError):
-                x0 = x0
+                try:
+                    xx = np.atleast_1d(np.asarray(x0))
+                    if len(xx) == 1:
+                        # this keeps units for singletons...
+                        x0 = x0
+                    else:
+                        # fallback for objects with length, but strange
+                        # ways of indexing (i.e. pandas)
+                        x0 = xx[0]
+                except:
+                    # generic except.  Think this should never happen, but...
+                    x0 = x0
 
             try:
                 x = xconv[0]
             except (TypeError, IndexError, KeyError):
-                x = xconv
+                try:
+                    xx = np.atleast_1d(np.asarray(xconv))
+                    if len(xx) == 1:
+                        x = xconv
+                    else:
+                        x = xx[0]
+                except:
+                    # generic except.  Think this should never happen, but...
+                    x = xconv
 
             delist = False
             if not np.iterable(dx):

lib/matplotlib/tests/test_axes.py

@@ -1647,6 +1647,14 @@ def test_bar_pandas(pd):
     ax.plot(dates, baseline, color='orange', lw=4)
 
 
+def test_bar_pandas_indexed(pd):
+    # Smoke test for indexed pandas
+    df = pd.DataFrame({"x": [1., 2., 3.], "width": [.2, .4, .6]},
+                       index=[1, 2, 3])
+    fig, ax = plt.subplots()
+    ax.bar(df.x, 1., width=df.width)
+
+
 @image_comparison(['hist_log'], remove_text=True)
 def test_hist_log():
     data0 = np.linspace(0, 1, 200)**3