Repository: great-expectations/great_expectations

Issue:
Use cleaner solution for non-truncating division in python 2
Prefer `from __future__ import division` to `1.*x/y`


Discussion:
Done inline during improve_partitions push.

Resolving patch:
diff --git a/contrib/experimental/great_expectations_experimental/expectations/expect_multicolumn_sum_values_to_be_between.py b/contrib/experimental/great_expectations_experimental/expectations/expect_multicolumn_sum_values_to_be_between.py
new file mode 100644
--- /dev/null
+++ b/contrib/experimental/great_expectations_experimental/expectations/expect_multicolumn_sum_values_to_be_between.py
@@ -0,0 +1,210 @@
+"""
+This is a template for creating custom MulticolumnMapExpectations.
+For detailed instructions on how to use it, please see:
+    https://docs.greatexpectations.io/docs/guides/expectations/creating_custom_expectations/how_to_create_custom_multicolumn_map_expectations
+"""
+import functools
+import operator
+from typing import Optional
+
+from great_expectations.core.expectation_configuration import \
+    ExpectationConfiguration
+from great_expectations.exceptions import InvalidExpectationConfigurationError
+from great_expectations.execution_engine import (PandasExecutionEngine,
+                                                 SparkDFExecutionEngine,
+                                                 SqlAlchemyExecutionEngine)
+from great_expectations.expectations.expectation import \
+    MulticolumnMapExpectation
+from great_expectations.expectations.metrics.import_manager import F
+from great_expectations.expectations.metrics.map_metric_provider import (
+    MulticolumnMapMetricProvider, multicolumn_condition_partial)
+
+
+# This class defines a Metric to support your Expectation.
+# For most MulticolumnMapExpectations, the main business logic for calculation will live in this class.
+class MulticolumnValuesSumValuesToBeBetweenMaxAndMin(MulticolumnMapMetricProvider):
+    # This is the id string that will be used to reference your metric.
+    condition_metric_name = "multicolumn_values.sum_values_to_be_between_max_and_min"
+    # These point your metric at the provided keys to facilitate calculation
+    condition_domain_keys = (
+        "batch_id",
+        "table",
+        "column_list",
+        "row_condition",
+        "condition_parser",
+        "ignore_row_if",
+    )
+    condition_value_keys = (
+        "min_value",
+        "max_value",
+    )
+
+    # This method implements the core logic for the PandasExecutionEngine
+    @multicolumn_condition_partial(engine=PandasExecutionEngine)
+    def _pandas(cls, column_list, min_value, max_value, **kwargs):
+        columns_to_sum = column_list.columns
+        sum_of_columns = column_list.sum(axis=1)
+        return (sum_of_columns >= min_value) & (sum_of_columns <= max_value)
+
+    # This method defines the business logic for evaluating your metric when using a SqlAlchemyExecutionEngine
+    # @multicolumn_condition_partial(engine=SqlAlchemyExecutionEngine)
+    # def _sqlalchemy(cls, column_list, **kwargs):
+    #     raise NotImplementedError
+
+    # This method defines the business logic for evaluating your metric when using a SparkDFExecutionEngine
+    @multicolumn_condition_partial(engine=SparkDFExecutionEngine)
+    def _spark(cls, column_list, min_value, max_value, **kwargs):
+        columns_to_sum = column_list.columns
+        return (
+            functools.reduce(operator.add, [F.col(column) for column in columns_to_sum])
+            >= F.lit(min_value)
+        ) & (
+            functools.reduce(operator.add, [F.col(column) for column in columns_to_sum])
+            <= F.lit(max_value)
+        )
+
+
+# This class defines the Expectation itself
+class ExpectMulticolumnSumValuesToBeBetween(MulticolumnMapExpectation):
+    """Expect a sum of values over the columns to be between max and min values
+    
+    min_value <= SUM(col_a, cob_b, cob_c, ...) <= max_value
+
+    Args:
+    column_list (list of str): \
+        A list of 2 or more integer columns 
+    min_value (int): \
+        A value that the sum of values over the column must be equal to or more than the given value
+    max_value (int): \
+        A value that the sum of values over the column must be equal to or less than the given value
+    """
+
+    # These examples will be shown in the public gallery.
+    # They will also be executed as unit tests for your Expectation.
+    examples = [
+        {
+            "data": {
+                "col_a": [3, 6, 9, 12, 3],
+                "col_b": [0, 3, 6, 33, 9],
+                "col_c": [1, 5, 6, 27, 3],
+            },
+            "tests": [
+                {
+                    "title": "multi_column_sum_to_equal_range_2-set_positive_test",
+                    "exact_match_out": False,
+                    "include_in_gallery": True,
+                    "in": {
+                        "column_list": ["col_a", "col_b"],
+                        "min_value": 1,
+                        "max_value": 50,
+                    },
+                    "out": {
+                        "success": True,
+                    },
+                },
+                {
+                    "title": "multi_column_sum_to_equal_range_3-set_positive_test",
+                    "exact_match_out": False,
+                    "include_in_gallery": True,
+                    "in": {
+                        "column_list": ["col_a", "col_b", "col_c"],
+                        "min_value": 4,
+                        "max_value": 72,
+                    },
+                    "out": {
+                        "success": True,
+                    },
+                },
+                {
+                    "title": "multi_column_sum_to_equal_range_2-set_negative_test",
+                    "exact_match_out": False,
+                    "include_in_gallery": True,
+                    "in": {
+                        "column_list": ["col_a", "col_b"],
+                        "min_value": 10,
+                        "max_value": 30,
+                    },
+                    "out": {
+                        "success": False,
+                    },
+                },
+                {
+                    "title": "multi_column_sum_to_equal_range_3-set_negative_test",
+                    "exact_match_out": False,
+                    "include_in_gallery": True,
+                    "in": {
+                        "column_list": ["col_a", "col_b", "col_c"],
+                        "min_value": 10,
+                        "max_value": 20,
+                    },
+                    "out": {
+                        "success": False,
+                    },
+                },
+            ],
+            "test_backends": [
+                {
+                    "backend": "spark",
+                    "dialects": None,
+                },
+                {
+                    "backend": "pandas",
+                    "dialects": None,
+                },
+            ],
+        }
+    ]
+
+    # This is the id string of the Metric used by this Expectation.
+    # For most Expectations, it will be the same as the `condition_metric_name` defined in your Metric class above.
+    map_metric = "multicolumn_values.sum_values_to_be_between_max_and_min"
+
+    # This is a list of parameter names that can affect whether the Expectation evaluates to True or False
+    success_keys = (
+        "min_value",
+        "max_value",
+    )
+
+    # This dictionary contains default values for any parameters that should have default values
+    default_kwarg_values = {}
+
+    def validate_configuration(
+        self, configuration: Optional[ExpectationConfiguration] = None
+    ) -> None:
+        """
+        Validates that a configuration has been set, and sets a configuration if it has yet to be set. Ensures that
+        necessary configuration arguments have been provided for the validation of the expectation.
+        Args:
+            configuration (OPTIONAL[ExpectationConfiguration]): \
+                An optional Expectation Configuration entry that will be used to configure the expectation
+        Returns:
+            None. Raises InvalidExpectationConfigurationError if the config is not validated successfully
+        """
+
+        super().validate_configuration(configuration)
+        configuration = configuration or self.configuration
+
+        # # Check other things in configuration.kwargs and raise Exceptions if needed
+        # try:
+        #     assert (
+        #         ...
+        #     ), "message"
+        #     assert (
+        #         ...
+        #     ), "message"
+        # except AssertionError as e:
+        #     raise InvalidExpectationConfigurationError(str(e))
+
+    # This object contains metadata for display in the public Gallery
+    library_metadata = {
+        "tags": [
+            "multi-column sum to be between min and max" "multi-column expectation"
+        ],  # Tags for this Expectation in the Gallery
+        "contributors": [  # Github handles for all contributors to this Expectation.
+            "@swittchawa",  # Don't forget to add your github handle here!
+        ],
+    }
+
+
+if __name__ == "__main__":
+    ExpectMulticolumnSumValuesToBeBetween().print_diagnostic_checklist()


Test patch: