From 10770e97fe6cad0870a5aabaffa09a3e76f04a69 Mon Sep 17 00:00:00 2001
From: Jody Klymak <jklymak@gmail.com>
Date: Sat, 31 Aug 2019 16:16:10 -0700
Subject: [PATCH 1/2] FIX: indexed pandas bar

---
 lib/matplotlib/axes/_axes.py      | 23 +++++++++++++++++++++--
 lib/matplotlib/tests/test_axes.py |  8 ++++++++
 2 files changed, 29 insertions(+), 2 deletions(-)

diff --git a/lib/matplotlib/axes/_axes.py b/lib/matplotlib/axes/_axes.py
index 40e48fd5512f..0f2ed3593e4c 100644
--- a/lib/matplotlib/axes/_axes.py
+++ b/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):
diff --git a/lib/matplotlib/tests/test_axes.py b/lib/matplotlib/tests/test_axes.py
index 01110ae26855..7830cde5f50d 100644
--- a/lib/matplotlib/tests/test_axes.py
+++ b/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

From a023ecf16b1c3a9739a6c644876172b08d14a965 Mon Sep 17 00:00:00 2001
From: Thomas A Caswell <tcaswell@gmail.com>
Date: Sun, 1 Sep 2019 12:49:23 -0400
Subject: [PATCH 2/2] MNT: simplify getting the first element

Use `safe_first_element` from cbook which does the `next(iter(x))`
dance to get the first element of an object (as defined by what you
get when you iterate over it).
---
 lib/matplotlib/axes/_axes.py | 27 ++++-----------------------
 1 file changed, 4 insertions(+), 23 deletions(-)

diff --git a/lib/matplotlib/axes/_axes.py b/lib/matplotlib/axes/_axes.py
index 0f2ed3593e4c..a4afe5e83fdc 100644
--- a/lib/matplotlib/axes/_axes.py
+++ b/lib/matplotlib/axes/_axes.py
@@ -2138,33 +2138,14 @@ def _convert_dx(dx, x0, xconv, convert):
             # removes the units from unit packages like `pint` that
             # wrap numpy arrays.
             try:
-                x0 = x0[0]
+                x0 = cbook.safe_first_element(x0)
             except (TypeError, IndexError, KeyError):
-                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
+                x0 = x0
 
             try:
-                x = xconv[0]
+                x = cbook.safe_first_element(xconv)
             except (TypeError, IndexError, KeyError):
-                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
+                x = xconv
 
             delist = False
             if not np.iterable(dx):