matplotlib · jklymak · Jan 29, 2024
diff --git a/lib/matplotlib/cbook.py b/lib/matplotlib/cbook.py
@@ -1411,13 +1411,17 @@ def _reshape_2D(X, name):
     *name* is used to generate the error message for invalid inputs.
     """
 
-    # Unpack in case of e.g. Pandas or xarray object
-    X = _unpack_to_numpy(X)
-
     # Iterate over columns for ndarrays.
-    if isinstance(X, np.ndarray):
+    if hasattr(X, 'iloc'):
+        # probably pandas...
+        # return each column as a separate list element
+        if X.ndim == 1:
+            return [np.array(X)]
+        elif X.ndim == 2:
+            return [np.array(X.iloc[:, i]) for i in range(X.shape[1])]
+
+    if hasattr(X, 'T') and hasattr(X, 'ndim'):
         X = X.T
-
         if len(X) == 0:
             return [[]]
         elif X.ndim == 1 and np.ndim(X[0]) == 0:

diff --git a/lib/matplotlib/tests/test_axes.py b/lib/matplotlib/tests/test_axes.py
@@ -6751,6 +6751,16 @@ def test_pandas_indexing_hist(pd):
     ax.hist(ser_2)
 
 
+def test_pandas_hist2D(pd):
+    np.random.seed(19680801)
+    x0 = np.random.randn(200, 3)
+    df = pd.DataFrame(x0, columns=["a", "b", "c"])
+    fig, ax = plt.subplots()
+    tops = ax.hist(df)
+    # one list of hist values for each column:
+    assert tops[0].shape[0] == 3
+
+
 def test_pandas_bar_align_center(pd):
     # Tests fix for issue 8767
     df = pd.DataFrame({'a': range(2), 'b': range(2)})