feat: Adds the ECharts Histogram chart (#28652)

tests/unit_tests/pandas_postprocessing/test_histogram.py

@@ -0,0 +1,122 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+from pandas import DataFrame
+
+from superset.utils.pandas_postprocessing import histogram
+
+data = DataFrame(
+    {
+        "group": ["A", "A", "B", "B", "A", "A", "B", "B", "A", "A"],
+        "a": [1, 2, 3, 4, 5, 6, 7, 8, 9, 10],
+        "b": [1, 2, 3, 4, 5, 6, 7, 8, 9, 10],
+    }
+)
+
+bins = 5
+
+
+def test_histogram_no_groupby():
+    data_with_no_groupings = DataFrame(
+        {"a": [1, 2, 3, 4, 5, 6, 7, 8, 9, 10], "b": [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]}
+    )
+    result = histogram(data_with_no_groupings, "a", [], bins)
+    assert result.shape == (1, bins)
+    assert result.columns.tolist() == ["1 - 2", "2 - 4", "4 - 6", "6 - 8", "8 - 10"]
+    assert result.values.tolist() == [[2, 2, 2, 2, 2]]
+
+
+def test_histogram_with_groupby():
+    result = histogram(data, "a", ["group"], bins)
+    assert result.shape == (2, bins + 1)
+    assert result.columns.tolist() == [
+        "group",
+        "1 - 2",
+        "2 - 4",
+        "4 - 6",
+        "6 - 8",
+        "8 - 10",
+    ]
+    assert result.values.tolist() == [["A", 2, 0, 2, 0, 2], ["B", 0, 2, 0, 2, 0]]
+
+
+def test_histogram_with_groupby_and_normalize():
+    result = histogram(data, "a", ["group"], bins, normalize=True)
+    assert result.shape == (2, bins + 1)
+    assert result.columns.tolist() == [
+        "group",
+        "1 - 2",
+        "2 - 4",
+        "4 - 6",
+        "6 - 8",
+        "8 - 10",
+    ]
+    assert result.values.tolist() == [
+        ["A", 0.2, 0.0, 0.2, 0.0, 0.2],
+        ["B", 0.0, 0.2, 0.0, 0.2, 0.0],
+    ]
+
+
+def test_histogram_with_groupby_and_cumulative():
+    result = histogram(data, "a", ["group"], bins, cumulative=True)
+    assert result.shape == (2, bins + 1)
+    assert result.columns.tolist() == [
+        "group",
+        "1 - 2",
+        "2 - 4",
+        "4 - 6",
+        "6 - 8",
+        "8 - 10",
+    ]
+    assert result.values.tolist() == [["A", 2, 2, 4, 4, 6], ["B", 0, 2, 2, 4, 4]]
+
+
+def test_histogram_with_groupby_and_cumulative_and_normalize():
+    result = histogram(data, "a", ["group"], bins, cumulative=True, normalize=True)
+    assert result.shape == (2, bins + 1)
+    assert result.columns.tolist() == [
+        "group",
+        "1 - 2",
+        "2 - 4",
+        "4 - 6",
+        "6 - 8",
+        "8 - 10",
+    ]
+    assert result.values.tolist() == [
+        [
+            "A",
+            0.06666666666666667,
+            0.06666666666666667,
+            0.13333333333333333,
+            0.13333333333333333,
+            0.2,
+        ],
+        [
+            "B",
+            0.0,
+            0.06666666666666667,
+            0.06666666666666667,
+            0.13333333333333333,
+            0.13333333333333333,
+        ],
+    ]
+
+
+def test_histogram_with_non_numeric_column():
+    try:
+        histogram(data, "b", ["group"], bins)
+    except ValueError as e:
+        assert str(e) == "The column 'b' must be numeric."