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_column_values_to_be_valid_uuid.py b/contrib/experimental/great_expectations_experimental/expectations/expect_column_values_to_be_valid_uuid.py
new file mode 100644
--- /dev/null
+++ b/contrib/experimental/great_expectations_experimental/expectations/expect_column_values_to_be_valid_uuid.py
@@ -0,0 +1,162 @@
+"""
+This is a template for creating custom ColumnMapExpectations.
+For detailed instructions on how to use it, please see:
+    https://docs.greatexpectations.io/docs/guides/expectations/creating_custom_expectations/how_to_create_custom_column_map_expectations
+"""
+
+import json
+from typing import Optional
+from uuid import UUID
+
+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 ColumnMapExpectation
+from great_expectations.expectations.metrics import (
+    ColumnMapMetricProvider,
+    column_condition_partial,
+)
+
+
+def is_valid_uuid(uuid: str) -> bool:
+    try:
+        UUID(uuid)
+        return True
+    except ValueError:
+        return False
+
+
+# This class defines a Metric to support your Expectation.
+# For most ColumnMapExpectations, the main business logic for calculation will live in this class.
+class ColumnValuesToBeValidUUID(ColumnMapMetricProvider):
+
+    # This is the id string that will be used to reference your metric.
+    condition_metric_name = "column_values.valid_uuid"
+
+    # This method implements the core logic for the PandasExecutionEngine
+    @column_condition_partial(engine=PandasExecutionEngine)
+    def _pandas(cls, column, **kwargs):
+        return column.apply(lambda x: is_valid_uuid(x))
+
+    # This method defines the business logic for evaluating your metric when using a SqlAlchemyExecutionEngine
+    # @column_condition_partial(engine=SqlAlchemyExecutionEngine)
+    # def _sqlalchemy(cls, column, _dialect, **kwargs):
+    #     raise NotImplementedError
+
+    # This method defines the business logic for evaluating your metric when using a SparkDFExecutionEngine
+    # @column_condition_partial(engine=SparkDFExecutionEngine)
+    # def _spark(cls, column, **kwargs):
+    #     raise NotImplementedError
+
+
+# This class defines the Expectation itself
+class ExpectColumnValuesToBeValidUUID(ColumnMapExpectation):
+    """This Expectation validates data as conforming to a valid UUID format."""
+
+    # These examples will be shown in the public gallery.
+    # They will also be executed as unit tests for your Expectation.
+    examples = [
+        {
+            "data": {
+                "well_formed_uuids": [
+                    # standard random UUIDs
+                    "28d12e8e-80aa-4b32-8afb-19da0aa7e3d5",
+                    "d711cb07-1f05-4ef6-bc54-3a5ec703a88d",
+                    "9d5175ae-4d9e-4370-854c-a5e9bbb9b2c7",
+                    "c3eef74b-d977-46e3-ad40-0bfe5dbaf64b",
+                    # hyphens may or may not be present
+                    "e8a4926e5f7643079e8acdbd49a4e15b",
+                    # curly braces may or may not be present
+                    "{00010203-0405-0607-0809-0a0b0c0d0e0f}",
+                    # leading identifier "urn:uuid:" is allowed
+                    "urn:uuid:12345678-1234-5678-1234-567812345678",
+                ],
+                "malformed_uuids": [
+                    # has non-hexidecimal value
+                    "5d700619-51de-4e28-b949-f596cddcd25z",
+                    # is too long
+                    "ff4a6854-79b9-4210-82b3-ca7cd6d03b711",
+                    # is too short
+                    "19bf8112-a972-4e38-a404-16864cb9d88",
+                    # has invalid punctuation
+                    "f13cbe4c_05df_4cbf_88f6_3b8c7d2f5cfc",
+                    # more invalid punctuation
+                    "a82af99c.20d3.4bb4.9a73.b9ec7c6f6a36",
+                    # left field
+                    "not-even-close",
+                    "ValueError('All arrays must be of the same length')",
+                ],
+            },
+            "tests": [
+                {
+                    "title": "basic_positive_test",
+                    "exact_match_out": False,
+                    "include_in_gallery": True,
+                    "in": {"column": "well_formed_uuids"},
+                    "out": {"success": True},
+                },
+                {
+                    "title": "basic_negative_test",
+                    "exact_match_out": False,
+                    "include_in_gallery": True,
+                    "in": {"column": "malformed_uuids"},
+                    "out": {"success": False},
+                },
+            ],
+        }
+    ]
+
+    # 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 = "column_values.valid_uuid"
+
+    # This is a list of parameter names that can affect whether the Expectation evaluates to True or False
+    success_keys = ("mostly",)
+
+    # This dictionary contains default values for any parameters that should have default values
+    default_kwarg_values = {}
+
+    def validate_configuration(self, configuration: Optional[ExpectationConfiguration]):
+        """
+        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:
+            True if the configuration has been validated successfully. Otherwise, raises an exception
+        """
+
+        super().validate_configuration(configuration)
+        if configuration is None:
+            configuration = 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))
+
+        return True
+
+    # This object contains metadata for display in the public Gallery
+    library_metadata = {
+        "tags": ["typed-entities"],  # Tags for this Expectation in the Gallery
+        "contributors": [  # Github handles for all contributors to this Expectation.
+            "@joshua-stauffer",  # Don't forget to add your github handle here!
+        ],
+    }
+
+
+if __name__ == "__main__":
+    ExpectColumnValuesToBeValidUUID().print_diagnostic_checklist()


Test patch: