From 716f0a7f991d187cc00e92eb3eb381b71241efad Mon Sep 17 00:00:00 2001
From: Stefanie Molin <24376333+stefmolin@users.noreply.github.com>
Date: Sat, 30 Jul 2022 17:44:59 -0400
Subject: [PATCH 01/11] Add labels argument to bar().

---
 lib/matplotlib/axes/_axes.py      | 24 +++++++++++++++++++-----
 lib/matplotlib/tests/test_axes.py | 16 ++++++++++++++++
 2 files changed, 35 insertions(+), 5 deletions(-)

diff --git a/lib/matplotlib/axes/_axes.py b/lib/matplotlib/axes/_axes.py
index 25b3cf36651f..f5d053569b01 100644
--- a/lib/matplotlib/axes/_axes.py
+++ b/lib/matplotlib/axes/_axes.py
@@ -2236,6 +2236,10 @@ def bar(self, x, height, width=0.8, bottom=None, *, align="center",
             To align the bars on the right edge pass a negative *width* and
             ``align='edge'``.
 
+        labels : str or list of str, optional
+            A sequence of labels to assign to each data series.
+            If unspecified, then ``'_nolegend_'`` will be applied to each bar.
+
         Returns
         -------
         `.BarContainer`
@@ -2302,8 +2306,6 @@ def bar(self, x, height, width=0.8, bottom=None, *, align="center",
         """
         kwargs = cbook.normalize_kwargs(kwargs, mpatches.Patch)
         color = kwargs.pop('color', None)
-        if color is None:
-            color = self._get_patches_for_fill.get_next_color()
         edgecolor = kwargs.pop('edgecolor', None)
         linewidth = kwargs.pop('linewidth', None)
         hatch = kwargs.pop('hatch', None)
@@ -2381,6 +2383,18 @@ def bar(self, x, height, width=0.8, bottom=None, *, align="center",
             tick_label_axis = self.yaxis
             tick_label_position = y
 
+        patch_labels = kwargs.pop('labels', ['_nolegend_'] * len(x))
+        if len(patch_labels) != len(x):
+            raise ValueError(f'number of labels ({len(patch_labels)}) '
+                             f'does not match number of bars ({len(x)}).')
+        if patch_labels[0] != '_nolegend_' and color is None:
+            color = [
+                self._get_patches_for_fill.get_next_color()
+                for _ in patch_labels
+            ]
+        elif color is None:
+            color = self._get_patches_for_fill.get_next_color()
+
         linewidth = itertools.cycle(np.atleast_1d(linewidth))
         hatch = itertools.cycle(np.atleast_1d(hatch))
         color = itertools.chain(itertools.cycle(mcolors.to_rgba_array(color)),
@@ -2420,14 +2434,14 @@ def bar(self, x, height, width=0.8, bottom=None, *, align="center",
 
         patches = []
         args = zip(left, bottom, width, height, color, edgecolor, linewidth,
-                   hatch)
-        for l, b, w, h, c, e, lw, htch in args:
+                   hatch, patch_labels)
+        for l, b, w, h, c, e, lw, htch, lbl in args:
             r = mpatches.Rectangle(
                 xy=(l, b), width=w, height=h,
                 facecolor=c,
                 edgecolor=e,
                 linewidth=lw,
-                label='_nolegend_',
+                label=lbl,
                 hatch=htch,
                 )
             r._internal_update(kwargs)
diff --git a/lib/matplotlib/tests/test_axes.py b/lib/matplotlib/tests/test_axes.py
index 51fbea3cfaaa..d90f0656957f 100644
--- a/lib/matplotlib/tests/test_axes.py
+++ b/lib/matplotlib/tests/test_axes.py
@@ -1886,6 +1886,22 @@ def test_bar_hatches(fig_test, fig_ref):
     ax_test.bar(x, y, hatch=hatches)
 
 
+@pytest.mark.parametrize(
+    ("x", "width", "labels", "color"),
+    [
+        ("x", 1, "x", None),
+        ("x", 1, "x", "black"),
+        (["a", "b", "c"], [10, 20, 15], ["A", "B", "C"], None),
+        (["a", "b", "c"], [10, 20, 15], ["A", "B", "C"],
+         ["black", "blue", "orange"]),
+    ]
+)
+def test_bar_labels(x, width, labels, color):
+    _, ax = plt.subplots()
+    ax.bar(x, width, labels=labels, color=color)
+    ax.legend()
+
+
 def test_pandas_minimal_plot(pd):
     # smoke test that series and index objects do not warn
     for x in [pd.Series([1, 2], dtype="float64"),

From 03b652483cdbfc13ab105de41b896613c6c8bc39 Mon Sep 17 00:00:00 2001
From: Stefanie Molin <24376333+stefmolin@users.noreply.github.com>
Date: Sat, 30 Jul 2022 17:58:57 -0400
Subject: [PATCH 02/11] Add what's new users entry.

---
 doc/users/next_whats_new/bar_plot_labels | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)
 create mode 100644 doc/users/next_whats_new/bar_plot_labels

diff --git a/doc/users/next_whats_new/bar_plot_labels b/doc/users/next_whats_new/bar_plot_labels
new file mode 100644
index 000000000000..c57eb2bc283d
--- /dev/null
+++ b/doc/users/next_whats_new/bar_plot_labels
@@ -0,0 +1,16 @@
+Easier labelling of bars in bar plot
+------------------------------------
+
+The new ``labels`` argument of `~matplotlib.axes.Axes.bar` can now 
+be used to label each of the bars.
+
+.. code-block:: python
+
+    import matplotlib.pyplot as plt
+
+    x = ["a", "b", "c"]
+    y = [10, 20, 15]
+
+    fig, ax = plt.subplots()
+    _ = ax.barh(x, y, labels=x)
+    ax.legend()

From 3dbe540cc34e4b26ee083ca1472a0d2e9840d4eb Mon Sep 17 00:00:00 2001
From: Stefanie Molin <24376333+stefmolin@users.noreply.github.com>
Date: Sat, 30 Jul 2022 18:19:31 -0400
Subject: [PATCH 03/11] Fix doc entry.

---
 .../next_whats_new/{bar_plot_labels => bar_plot_labels.rst}     | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
 rename doc/users/next_whats_new/{bar_plot_labels => bar_plot_labels.rst} (98%)

diff --git a/doc/users/next_whats_new/bar_plot_labels b/doc/users/next_whats_new/bar_plot_labels.rst
similarity index 98%
rename from doc/users/next_whats_new/bar_plot_labels
rename to doc/users/next_whats_new/bar_plot_labels.rst
index c57eb2bc283d..1cd942fa96e4 100644
--- a/doc/users/next_whats_new/bar_plot_labels
+++ b/doc/users/next_whats_new/bar_plot_labels.rst
@@ -1,7 +1,7 @@
 Easier labelling of bars in bar plot
 ------------------------------------
 
-The new ``labels`` argument of `~matplotlib.axes.Axes.bar` can now 
+The new ``labels`` argument of `~matplotlib.axes.Axes.bar` can now
 be used to label each of the bars.
 
 .. code-block:: python

From b975db21474baf6bd88ba5c1d0abdbac9df1c87e Mon Sep 17 00:00:00 2001
From: Stefanie Molin <24376333+stefmolin@users.noreply.github.com>
Date: Sat, 30 Jul 2022 18:40:18 -0400
Subject: [PATCH 04/11] Add test for mismatch in label length and data length.

---
 lib/matplotlib/tests/test_axes.py | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/lib/matplotlib/tests/test_axes.py b/lib/matplotlib/tests/test_axes.py
index d90f0656957f..2b8cee19c8c1 100644
--- a/lib/matplotlib/tests/test_axes.py
+++ b/lib/matplotlib/tests/test_axes.py
@@ -1902,6 +1902,12 @@ def test_bar_labels(x, width, labels, color):
     ax.legend()
 
 
+def test_bar_labels_length():
+    _, ax = plt.subplots()
+    with pytest.raises(ValueError):
+        ax.bar(["x", "y"], [1, 2], labels="X")
+
+
 def test_pandas_minimal_plot(pd):
     # smoke test that series and index objects do not warn
     for x in [pd.Series([1, 2], dtype="float64"),

From a0ed19657013515b87505d928dd339da91c0fdb6 Mon Sep 17 00:00:00 2001
From: Stefanie Molin <24376333+stefmolin@users.noreply.github.com>
Date: Sun, 31 Jul 2022 11:23:14 -0400
Subject: [PATCH 05/11] Switch to 'label' argument.

---
 doc/users/next_whats_new/bar_plot_labels.rst |  8 +++----
 lib/matplotlib/axes/_axes.py                 | 22 +++++++-------------
 lib/matplotlib/tests/test_axes.py            | 19 +++++++++--------
 3 files changed, 22 insertions(+), 27 deletions(-)

diff --git a/doc/users/next_whats_new/bar_plot_labels.rst b/doc/users/next_whats_new/bar_plot_labels.rst
index 1cd942fa96e4..6da57a317f59 100644
--- a/doc/users/next_whats_new/bar_plot_labels.rst
+++ b/doc/users/next_whats_new/bar_plot_labels.rst
@@ -1,8 +1,8 @@
 Easier labelling of bars in bar plot
 ------------------------------------
 
-The new ``labels`` argument of `~matplotlib.axes.Axes.bar` can now
-be used to label each of the bars.
+The ``label`` argument of `~matplotlib.axes.Axes.bar` can now
+be passed a list of labels for the bars.
 
 .. code-block:: python
 
@@ -12,5 +12,5 @@ be used to label each of the bars.
     y = [10, 20, 15]
 
     fig, ax = plt.subplots()
-    _ = ax.barh(x, y, labels=x)
-    ax.legend()
+    bar_container = ax.barh(x, y, label=x)
+    [bar.get_label() for bar in bar_container]
diff --git a/lib/matplotlib/axes/_axes.py b/lib/matplotlib/axes/_axes.py
index f5d053569b01..f9f579e4995f 100644
--- a/lib/matplotlib/axes/_axes.py
+++ b/lib/matplotlib/axes/_axes.py
@@ -2236,10 +2236,6 @@ def bar(self, x, height, width=0.8, bottom=None, *, align="center",
             To align the bars on the right edge pass a negative *width* and
             ``align='edge'``.
 
-        labels : str or list of str, optional
-            A sequence of labels to assign to each data series.
-            If unspecified, then ``'_nolegend_'`` will be applied to each bar.
-
         Returns
         -------
         `.BarContainer`
@@ -2306,6 +2302,8 @@ def bar(self, x, height, width=0.8, bottom=None, *, align="center",
         """
         kwargs = cbook.normalize_kwargs(kwargs, mpatches.Patch)
         color = kwargs.pop('color', None)
+        if color is None:
+            color = self._get_patches_for_fill.get_next_color()
         edgecolor = kwargs.pop('edgecolor', None)
         linewidth = kwargs.pop('linewidth', None)
         hatch = kwargs.pop('hatch', None)
@@ -2383,17 +2381,13 @@ def bar(self, x, height, width=0.8, bottom=None, *, align="center",
             tick_label_axis = self.yaxis
             tick_label_position = y
 
-        patch_labels = kwargs.pop('labels', ['_nolegend_'] * len(x))
+        patch_labels = np.atleast_1d(label)
         if len(patch_labels) != len(x):
-            raise ValueError(f'number of labels ({len(patch_labels)}) '
-                             f'does not match number of bars ({len(x)}).')
-        if patch_labels[0] != '_nolegend_' and color is None:
-            color = [
-                self._get_patches_for_fill.get_next_color()
-                for _ in patch_labels
-            ]
-        elif color is None:
-            color = self._get_patches_for_fill.get_next_color()
+            if len(patch_labels) == 1:
+                patch_labels = ['_nolegend_'] * len(x)
+            else:
+                raise ValueError(f'number of labels ({len(patch_labels)}) '
+                                 f'does not match number of bars ({len(x)}).')
 
         linewidth = itertools.cycle(np.atleast_1d(linewidth))
         hatch = itertools.cycle(np.atleast_1d(hatch))
diff --git a/lib/matplotlib/tests/test_axes.py b/lib/matplotlib/tests/test_axes.py
index 2b8cee19c8c1..63c058b4974c 100644
--- a/lib/matplotlib/tests/test_axes.py
+++ b/lib/matplotlib/tests/test_axes.py
@@ -1887,25 +1887,26 @@ def test_bar_hatches(fig_test, fig_ref):
 
 
 @pytest.mark.parametrize(
-    ("x", "width", "labels", "color"),
+    ("x", "width", "label", "expected_labels"),
     [
-        ("x", 1, "x", None),
-        ("x", 1, "x", "black"),
-        (["a", "b", "c"], [10, 20, 15], ["A", "B", "C"], None),
+        ("x", 1, "x", ["x"]),
         (["a", "b", "c"], [10, 20, 15], ["A", "B", "C"],
-         ["black", "blue", "orange"]),
+         ["A", "B", "C"]),
+        (["a", "b", "c"], [10, 20, 15], "bars",
+         ["_nolegend_", "_nolegend_", "_nolegend_"]),
     ]
 )
-def test_bar_labels(x, width, labels, color):
+def test_bar_labels(x, width, label, expected_labels):
     _, ax = plt.subplots()
-    ax.bar(x, width, labels=labels, color=color)
-    ax.legend()
+    bar_container = ax.bar(x, width, label=label)
+    bar_labels = [bar.get_label() for bar in bar_container]
+    assert expected_labels == bar_labels
 
 
 def test_bar_labels_length():
     _, ax = plt.subplots()
     with pytest.raises(ValueError):
-        ax.bar(["x", "y"], [1, 2], labels="X")
+        ax.bar(["x", "y"], [1, 2], label=["X", "Y", "Z"])
 
 
 def test_pandas_minimal_plot(pd):

From bc5b1a1ef03521777dffca4d29a74ad2e3bb75c1 Mon Sep 17 00:00:00 2001
From: Stefanie Molin <24376333+stefmolin@users.noreply.github.com>
Date: Wed, 17 Aug 2022 22:11:46 -0400
Subject: [PATCH 06/11] Handle duplicate bar labels in legend; address PR
 comments.

---
 lib/matplotlib/axes/_axes.py | 30 +++++++++++++++++++++++-------
 1 file changed, 23 insertions(+), 7 deletions(-)

diff --git a/lib/matplotlib/axes/_axes.py b/lib/matplotlib/axes/_axes.py
index f9f579e4995f..d1c5989b8299 100644
--- a/lib/matplotlib/axes/_axes.py
+++ b/lib/matplotlib/axes/_axes.py
@@ -2256,6 +2256,13 @@ def bar(self, x, height, width=0.8, bottom=None, *, align="center",
             The tick labels of the bars.
             Default: None (Use default numeric labels.)
 
+        label : str or list of str, optional
+            A single label is attached to the resulting BarContainer as a
+            label for the whole dataset.
+            If a list is given, it must be the same length as *x* and
+            labels the individual bars. For example this may used with
+            lists of *color*.
+
         xerr, yerr : float or array-like of shape(N,) or shape(2, N), optional
             If not *None*, add horizontal / vertical errorbars to the bar tips.
             The values are +/- sizes relative to the data:
@@ -2381,13 +2388,21 @@ def bar(self, x, height, width=0.8, bottom=None, *, align="center",
             tick_label_axis = self.yaxis
             tick_label_position = y
 
-        patch_labels = np.atleast_1d(label)
+        if not isinstance(label, str) and np.iterable(label):
+            bar_container_label = '_nolegend_'
+            seen_labels = set()
+            patch_labels = label
+            for i, patch_label in enumerate(patch_labels):
+                if patch_label in seen_labels:
+                    patch_labels[i] = '_nolegend_'
+                else:
+                    seen_labels.add(patch_label)
+        else:
+            bar_container_label = label
+            patch_labels = ['_nolegend_'] * len(x)
         if len(patch_labels) != len(x):
-            if len(patch_labels) == 1:
-                patch_labels = ['_nolegend_'] * len(x)
-            else:
-                raise ValueError(f'number of labels ({len(patch_labels)}) '
-                                 f'does not match number of bars ({len(x)}).')
+            raise ValueError(f'number of labels ({len(patch_labels)}) '
+                             f'does not match number of bars ({len(x)}).')
 
         linewidth = itertools.cycle(np.atleast_1d(linewidth))
         hatch = itertools.cycle(np.atleast_1d(hatch))
@@ -2474,7 +2489,8 @@ def bar(self, x, height, width=0.8, bottom=None, *, align="center",
             datavalues = width
 
         bar_container = BarContainer(patches, errorbar, datavalues=datavalues,
-                                     orientation=orientation, label=label)
+                                     orientation=orientation,
+                                     label=bar_container_label)
         self.add_container(bar_container)
 
         if tick_labels is not None:

From 72fd2b4689936a02e4318e6d74e8298c0f746d5f Mon Sep 17 00:00:00 2001
From: Stefanie Molin <24376333+stefmolin@users.noreply.github.com>
Date: Wed, 17 Aug 2022 22:29:37 -0400
Subject: [PATCH 07/11] Add tests.

---
 lib/matplotlib/tests/test_axes.py | 25 ++++++++++++++++++++-----
 1 file changed, 20 insertions(+), 5 deletions(-)

diff --git a/lib/matplotlib/tests/test_axes.py b/lib/matplotlib/tests/test_axes.py
index 63c058b4974c..387cdfe70642 100644
--- a/lib/matplotlib/tests/test_axes.py
+++ b/lib/matplotlib/tests/test_axes.py
@@ -1887,26 +1887,41 @@ def test_bar_hatches(fig_test, fig_ref):
 
 
 @pytest.mark.parametrize(
-    ("x", "width", "label", "expected_labels"),
+    ("x", "width", "label", "expected_labels", "container_label"),
     [
-        ("x", 1, "x", ["x"]),
+        ("x", 1, "x", ["_nolegend_"], "x"),
         (["a", "b", "c"], [10, 20, 15], ["A", "B", "C"],
-         ["A", "B", "C"]),
+         ["A", "B", "C"], "_nolegend_"),
+        (["a", "b", "c"], [10, 20, 15], ["R", "Y", "R"],
+         ["R", "Y", "_nolegend_"], "_nolegend_"),
         (["a", "b", "c"], [10, 20, 15], "bars",
-         ["_nolegend_", "_nolegend_", "_nolegend_"]),
+         ["_nolegend_", "_nolegend_", "_nolegend_"], "bars"),
     ]
 )
-def test_bar_labels(x, width, label, expected_labels):
+def test_bar_labels(x, width, label, expected_labels, container_label):
     _, ax = plt.subplots()
     bar_container = ax.bar(x, width, label=label)
     bar_labels = [bar.get_label() for bar in bar_container]
     assert expected_labels == bar_labels
+    assert bar_container.get_label() == container_label
 
 
 def test_bar_labels_length():
     _, ax = plt.subplots()
     with pytest.raises(ValueError):
         ax.bar(["x", "y"], [1, 2], label=["X", "Y", "Z"])
+    _, ax = plt.subplots()
+    with pytest.raises(ValueError):
+        ax.bar(["x", "y"], [1, 2], label=["X"])
+
+
+def test_duplicate_bar_labels_in_legend():
+    _, ax = plt.subplots()
+    x = ["a", "b", "c"]
+    y = [2, 1, 3]
+    labels = ["Red", "Yellow", "Red"]
+    ax.bar(x, y, label=labels)
+    assert [text.get_text() for text in ax.legend().texts] == labels[:2]
 
 
 def test_pandas_minimal_plot(pd):

From 8a5ab0e409e45e7f0073b1e2b7c76036a67aeb66 Mon Sep 17 00:00:00 2001
From: Stefanie Molin <24376333+stefmolin@users.noreply.github.com>
Date: Wed, 17 Aug 2022 22:31:49 -0400
Subject: [PATCH 08/11] Update label description in docstring.

---
 lib/matplotlib/axes/_axes.py | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/lib/matplotlib/axes/_axes.py b/lib/matplotlib/axes/_axes.py
index d1c5989b8299..b75ffe895955 100644
--- a/lib/matplotlib/axes/_axes.py
+++ b/lib/matplotlib/axes/_axes.py
@@ -2257,10 +2257,10 @@ def bar(self, x, height, width=0.8, bottom=None, *, align="center",
             Default: None (Use default numeric labels.)
 
         label : str or list of str, optional
-            A single label is attached to the resulting BarContainer as a
+            A single label is attached to the resulting `.BarContainer` as a
             label for the whole dataset.
-            If a list is given, it must be the same length as *x* and
-            labels the individual bars. For example this may used with
+            If a list is provided, it must be the same length as *x* and
+            labels the individual bars. For example, this may used with
             lists of *color*.
 
         xerr, yerr : float or array-like of shape(N,) or shape(2, N), optional

From f71dc0c62591078a8e2372097bcd15b0776850ab Mon Sep 17 00:00:00 2001
From: Stefanie Molin <24376333+stefmolin@users.noreply.github.com>
Date: Wed, 17 Aug 2022 22:37:05 -0400
Subject: [PATCH 09/11] Remove duplicate label filtering.

---
 lib/matplotlib/axes/_axes.py      |  6 ------
 lib/matplotlib/tests/test_axes.py | 11 +----------
 2 files changed, 1 insertion(+), 16 deletions(-)

diff --git a/lib/matplotlib/axes/_axes.py b/lib/matplotlib/axes/_axes.py
index b75ffe895955..b9353b9b1617 100644
--- a/lib/matplotlib/axes/_axes.py
+++ b/lib/matplotlib/axes/_axes.py
@@ -2390,13 +2390,7 @@ def bar(self, x, height, width=0.8, bottom=None, *, align="center",
 
         if not isinstance(label, str) and np.iterable(label):
             bar_container_label = '_nolegend_'
-            seen_labels = set()
             patch_labels = label
-            for i, patch_label in enumerate(patch_labels):
-                if patch_label in seen_labels:
-                    patch_labels[i] = '_nolegend_'
-                else:
-                    seen_labels.add(patch_label)
         else:
             bar_container_label = label
             patch_labels = ['_nolegend_'] * len(x)
diff --git a/lib/matplotlib/tests/test_axes.py b/lib/matplotlib/tests/test_axes.py
index 387cdfe70642..3a1ba341b2e0 100644
--- a/lib/matplotlib/tests/test_axes.py
+++ b/lib/matplotlib/tests/test_axes.py
@@ -1892,7 +1892,7 @@ def test_bar_hatches(fig_test, fig_ref):
         ("x", 1, "x", ["_nolegend_"], "x"),
         (["a", "b", "c"], [10, 20, 15], ["A", "B", "C"],
          ["A", "B", "C"], "_nolegend_"),
-        (["a", "b", "c"], [10, 20, 15], ["R", "Y", "R"],
+        (["a", "b", "c"], [10, 20, 15], ["R", "Y", "_nolegend_"],
          ["R", "Y", "_nolegend_"], "_nolegend_"),
         (["a", "b", "c"], [10, 20, 15], "bars",
          ["_nolegend_", "_nolegend_", "_nolegend_"], "bars"),
@@ -1915,15 +1915,6 @@ def test_bar_labels_length():
         ax.bar(["x", "y"], [1, 2], label=["X"])
 
 
-def test_duplicate_bar_labels_in_legend():
-    _, ax = plt.subplots()
-    x = ["a", "b", "c"]
-    y = [2, 1, 3]
-    labels = ["Red", "Yellow", "Red"]
-    ax.bar(x, y, label=labels)
-    assert [text.get_text() for text in ax.legend().texts] == labels[:2]
-
-
 def test_pandas_minimal_plot(pd):
     # smoke test that series and index objects do not warn
     for x in [pd.Series([1, 2], dtype="float64"),

From 6ad5dcf409ab17021f0a877730034b29be2274f1 Mon Sep 17 00:00:00 2001
From: Stefanie Molin <24376333+stefmolin@users.noreply.github.com>
Date: Thu, 18 Aug 2022 08:38:27 -0400
Subject: [PATCH 10/11] Add note on repeated labels.

---
 lib/matplotlib/axes/_axes.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lib/matplotlib/axes/_axes.py b/lib/matplotlib/axes/_axes.py
index b9353b9b1617..e265da224bdc 100644
--- a/lib/matplotlib/axes/_axes.py
+++ b/lib/matplotlib/axes/_axes.py
@@ -2261,7 +2261,8 @@ def bar(self, x, height, width=0.8, bottom=None, *, align="center",
             label for the whole dataset.
             If a list is provided, it must be the same length as *x* and
             labels the individual bars. For example, this may used with
-            lists of *color*.
+            lists of *color*. Note that behavior for repeated labels is
+            not defined and may change in the future.
 
         xerr, yerr : float or array-like of shape(N,) or shape(2, N), optional
             If not *None*, add horizontal / vertical errorbars to the bar tips.

From 9f55a015650b81cbd75b22f922dffe7bba8934c0 Mon Sep 17 00:00:00 2001
From: Stefanie Molin <24376333+stefmolin@users.noreply.github.com>
Date: Thu, 18 Aug 2022 17:40:01 -0400
Subject: [PATCH 11/11] Update docstring per PR.

Co-authored-by: Elliott Sales de Andrade <quantum.analyst@gmail.com>
---
 lib/matplotlib/axes/_axes.py | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/lib/matplotlib/axes/_axes.py b/lib/matplotlib/axes/_axes.py
index e265da224bdc..3159a55b7e83 100644
--- a/lib/matplotlib/axes/_axes.py
+++ b/lib/matplotlib/axes/_axes.py
@@ -2260,9 +2260,9 @@ def bar(self, x, height, width=0.8, bottom=None, *, align="center",
             A single label is attached to the resulting `.BarContainer` as a
             label for the whole dataset.
             If a list is provided, it must be the same length as *x* and
-            labels the individual bars. For example, this may used with
-            lists of *color*. Note that behavior for repeated labels is
-            not defined and may change in the future.
+            labels the individual bars. Repeated labels are not de-duplicated
+            and will cause repeated label entries, so this is best used when
+            bars also differ in style (e.g., by passing a list to *color*.)
 
         xerr, yerr : float or array-like of shape(N,) or shape(2, N), optional
             If not *None*, add horizontal / vertical errorbars to the bar tips.