ENH: Add grouped_bar() method

Author: timhoffm

doc/_embedded_plots/grouped_bar.py

@@ -0,0 +1,15 @@
+import matplotlib.pyplot as plt
+
+categories = ['A', 'B']
+data0 = [1.0, 3.0]
+data1 = [1.4, 3.4]
+data2 = [1.8, 3.8]
+
+fig, ax = plt.subplots(figsize=(4, 2.2))
+ax.grouped_bar(
+    [data0, data1, data2],
+    tick_labels=categories,
+    labels=['dataset 0', 'dataset 1', 'dataset 2'],
+    colors=['#1f77b4', '#58a1cf', '#abd0e6'],
+)
+ax.legend()

doc/api/axes_api.rst

@@ -67,6 +67,7 @@ Basic
    Axes.bar
    Axes.barh
    Axes.bar_label
+   Axes.grouped_bar
 
    Axes.stem
    Axes.eventplot

doc/api/pyplot_summary.rst

@@ -61,6 +61,7 @@ Basic
    bar
    barh
    bar_label
+   grouped_bar
    stem
    eventplot
    pie

doc/users/next_whats_new/grouped_bar.rst

@@ -0,0 +1,25 @@
+Grouped bar charts
+------------------
+
+The new method `~.Axes.grouped_bar()` simplifies the creation of grouped bar charts
+significantly. It supports different input data types (lists of datasets, dicts of
+datasets, data in 2D arrays, pandas DataFrames), and allows for easy customization
+of placement via controllable distances between bars and between bar groups.
+
+Example:
+
+.. plot::
+    :include-source: true
+
+    import matplotlib.pyplot as plt
+
+    categories = ['A', 'B']
+    datasets = {
+        'dataset 0': [1.0, 3.0],
+        'dataset 1': [1.4, 3.4],
+        'dataset 2': [1.8, 3.8],
+    }
+
+    fig, ax = plt.subplots(figsize=(4, 2.2))
+    ax.grouped_bar(datasets, tick_labels=categories)
+    ax.legend()