BUG-CoW: from_records not tracking references when called with df

doc/source/whatsnew/v2.0.0.rst

@@ -190,6 +190,9 @@ Copy-on-Write improvements
   of Series objects and specifying ``copy=False``, will now use a lazy copy
   of those Series objects for the columns of the DataFrame (:issue:`50777`)
 
+- The :meth:`DataFrame.from_records` will now respect Copy-on-Write when called
+  with a :class:`DataFrame`.
+
 - Trying to set values using chained assignment (for example, ``df["a"][1:3] = 0``)
   will now always raise an warning when Copy-on-Write is enabled. In this mode,
   chained assignment can never work because we are always setting into a temporary

pandas/core/frame.py

@@ -2205,7 +2205,7 @@ def from_records(
                 data = data.set_index(index)
             if exclude is not None:
                 data = data.drop(columns=exclude)
-            return data
+            return data.copy(deep=False)
 
         result_index = None
 

pandas/tests/copy_view/test_constructors.py

@@ -179,3 +179,18 @@ def test_dataframe_from_dict_of_series_with_dtype(index):
     df.iloc[0, 0] = 100
     arr_after = get_array(df, "a")
     assert np.shares_memory(arr_before, arr_after)
+
+
+def test_dataframe_from_records_with_dataframe(using_copy_on_write):
+    df = DataFrame({"a": [1, 2, 3]})
+    df_orig = df.copy()
+    with tm.assert_produces_warning(FutureWarning):
+        df2 = DataFrame.from_records(df)
+    if using_copy_on_write:
+        assert not df._mgr._has_no_reference(0)
+    assert np.shares_memory(get_array(df, "a"), get_array(df2, "a"))
+    df2.iloc[0, 0] = 100
+    if using_copy_on_write:
+        tm.assert_frame_equal(df, df_orig)
+    else:
+        tm.assert_frame_equal(df, df2)