feat: Export datacontract to dqx

CHANGELOG.md

@@ -8,6 +8,11 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ## Unreleased
 
 
+### Added
+
+- Export to DQX : datacontract export --format dqx
+
+
 ## [0.10.34] - 2025-08-06
 
 ### Added

README.md

@@ -923,7 +923,7 @@ models:
 │                      terraform|avro-idl|sql|sql-query|mer                                        │
 │                      maid|html|go|bigquery|dbml|spark|sql                                        │
 │                      alchemy|data-caterer|dcs|markdown|ic                                        │
-│                      eberg|custom|excel]                                                         │
+│                      eberg|custom|excel|dqx]                                                         │
 │    --output          PATH                                  Specify the file path where the       │
 │                                                            exported data will be saved. If no    │
 │                                                            path is provided, the output will be  │
@@ -969,35 +969,36 @@ datacontract export --format html --output datacontract.html
 
 Available export options:
 
-| Type                 | Description                                             | Status |
-|----------------------|---------------------------------------------------------|--------|
-| `html`               | Export to HTML                                          | ✅      |
-| `jsonschema`         | Export to JSON Schema                                   | ✅      |
-| `odcs`               | Export to Open Data Contract Standard (ODCS) V3         | ✅      |
-| `sodacl`             | Export to SodaCL quality checks in YAML format          | ✅      |
-| `dbt`                | Export to dbt models in YAML format                     | ✅      |
-| `dbt-sources`        | Export to dbt sources in YAML format                    | ✅      |
-| `dbt-staging-sql`    | Export to dbt staging SQL models                        | ✅      |
-| `rdf`                | Export data contract to RDF representation in N3 format | ✅      |
-| `avro`               | Export to AVRO models                                   | ✅      |
-| `protobuf`           | Export to Protobuf                                      | ✅      |
-| `terraform`          | Export to terraform resources                           | ✅      |
-| `sql`                | Export to SQL DDL                                       | ✅      |
-| `sql-query`          | Export to SQL Query                                     | ✅      |
-| `great-expectations` | Export to Great Expectations Suites in JSON Format      | ✅      |
-| `bigquery`           | Export to BigQuery Schemas                              | ✅      |
-| `go`                 | Export to Go types                                      | ✅      |
-| `pydantic-model`     | Export to pydantic models                               | ✅      |
-| `DBML`               | Export to a DBML Diagram description                    | ✅      |
-| `spark`              | Export to a Spark StructType                            | ✅      |
-| `sqlalchemy`         | Export to SQLAlchemy Models                             | ✅      |
-| `data-caterer`       | Export to Data Caterer in YAML format                   | ✅      |
-| `dcs`                | Export to Data Contract Specification in YAML format    | ✅      |
-| `markdown`           | Export to Markdown                                      | ✅      |
+| Type                 | Description                                             | Status  |
+|----------------------|---------------------------------------------------------|---------|
+| `html`               | Export to HTML                                          | ✅       |
+| `jsonschema`         | Export to JSON Schema                                   | ✅       |
+| `odcs`               | Export to Open Data Contract Standard (ODCS) V3         | ✅       |
+| `sodacl`             | Export to SodaCL quality checks in YAML format          | ✅       |
+| `dbt`                | Export to dbt models in YAML format                     | ✅       |
+| `dbt-sources`        | Export to dbt sources in YAML format                    | ✅       |
+| `dbt-staging-sql`    | Export to dbt staging SQL models                        | ✅       |
+| `rdf`                | Export data contract to RDF representation in N3 format | ✅       |
+| `avro`               | Export to AVRO models                                   | ✅       |
+| `protobuf`           | Export to Protobuf                                      | ✅       |
+| `terraform`          | Export to terraform resources                           | ✅       |
+| `sql`                | Export to SQL DDL                                       | ✅       |
+| `sql-query`          | Export to SQL Query                                     | ✅       |
+| `great-expectations` | Export to Great Expectations Suites in JSON Format      | ✅       |
+| `bigquery`           | Export to BigQuery Schemas                              | ✅       |
+| `go`                 | Export to Go types                                      | ✅       |
+| `pydantic-model`     | Export to pydantic models                               | ✅       |
+| `DBML`               | Export to a DBML Diagram description                    | ✅       |
+| `spark`              | Export to a Spark StructType                            | ✅       |
+| `sqlalchemy`         | Export to SQLAlchemy Models                             | ✅       |
+| `data-caterer`       | Export to Data Caterer in YAML format                   | ✅       |
+| `dcs`                | Export to Data Contract Specification in YAML format    | ✅       |
+| `markdown`           | Export to Markdown                                      | ✅       |
 | `iceberg`            | Export to an Iceberg JSON Schema Definition             | partial |
-| `excel`              | Export to ODCS Excel Template                           | ✅      |
-| `custom`             | Export to Custom format with Jinja                      | ✅      |
-| Missing something?   | Please create an issue on GitHub                        | TBD    |
+| `excel`              | Export to ODCS Excel Template                           | ✅       |
+| `custom`             | Export to Custom format with Jinja                      | ✅       |
+| `dqx`                | Export to DQX in YAML format                            | ✅       |
+| Missing something?   | Please create an issue on GitHub                        | TBD     |
 
 #### SQL
 

datacontract/export/dqx_converter.py

@@ -0,0 +1,121 @@
+from typing import Any, Dict, List, Union
+
+import yaml
+
+from datacontract.export.exporter import Exporter, _check_models_for_export
+from datacontract.model.data_contract_specification import DataContractSpecification, Field, Model, Quality
+
+
+class DqxKeys:
+    CHECK = "check"
+    ARGUMENTS = "arguments"
+    SPECIFICATION = "specification"
+    COL_NAME = "column"
+    COL_NAMES = "for_each_column"
+    COLUMNS = "columns"
+    FUNCTION = "function"
+
+
+class DqxExporter(Exporter):
+    """Exporter implementation for converting data contracts to DQX YAML file."""
+
+    def export(
+        self,
+        data_contract: DataContractSpecification,
+        model: Model,
+        server: str,
+        sql_server_type: str,
+        export_args: Dict[str, Any],
+    ) -> str:
+        """Exports a data contract to DQX format."""
+        model_name, model_value = _check_models_for_export(data_contract, model, self.export_format)
+        return to_dqx_yaml(model_value)
+
+
+def to_dqx_yaml(model_value: Model) -> str:
+    """
+    Converts the data contract's quality checks to DQX YAML format.
+
+    Args:
+        model_value (Model): The data contract to convert.
+
+    Returns:
+        str: YAML representation of the data contract's quality checks.
+    """
+    extracted_rules = extract_quality_rules(model_value)
+    return yaml.dump(extracted_rules, sort_keys=False, allow_unicode=True, default_flow_style=False)
+
+
+def process_quality_rule(rule: Quality, column_name: str) -> Dict[str, Any]:
+    """
+    Processes a single quality rule by injecting the column path into its arguments if absent.
+
+    Args:
+        rule (Quality): The quality rule to process.
+        column_name (str): The full path to the current column.
+
+    Returns:
+        dict: The processed quality rule specification.
+    """
+    rule_data = rule.model_extra
+    specification = rule_data[DqxKeys.SPECIFICATION]
+    check = specification[DqxKeys.CHECK]
+
+    arguments = check.setdefault(DqxKeys.ARGUMENTS, {})
+
+    if DqxKeys.COL_NAME not in arguments and DqxKeys.COL_NAMES not in arguments and DqxKeys.COLUMNS not in arguments:
+        if check[DqxKeys.FUNCTION] not in ("is_unique", "foreign_key"):
+            arguments[DqxKeys.COL_NAME] = column_name
+        else:
+            arguments[DqxKeys.COLUMNS] = [column_name]
+
+    return specification
+
+
+def extract_quality_rules(data: Union[Model, Field, Quality], column_path: str = "") -> List[Dict[str, Any]]:
+    """
+    Recursively extracts all quality rules from a data contract structure.
+
+    Args:
+        data (Union[Model, Field, Quality]): The data contract model, field, or quality rule.
+        column_path (str, optional): The current path in the schema hierarchy. Defaults to "".
+
+    Returns:
+        List[Dict[str, Any]]: A list of quality rule specifications.
+    """
+    quality_rules = []
+
+    if isinstance(data, Quality):
+        return [process_quality_rule(data, column_path)]
+
+    if isinstance(data, (Model, Field)):
+        for key, field in data.fields.items():
+            current_path = build_column_path(column_path, key)
+
+            if field.fields:
+                # Field is a struct-like object, recurse deeper
+                quality_rules.extend(extract_quality_rules(field, current_path))
+            else:
+                # Process quality rules at leaf fields
+                for rule in field.quality:
+                    quality_rules.append(process_quality_rule(rule, current_path))
+
+        # Process any quality rules attached directly to this level
+        for rule in data.quality:
+            quality_rules.append(process_quality_rule(rule, column_path))
+
+    return quality_rules
+
+
+def build_column_path(current_path: str, key: str) -> str:
+    """
+    Builds the full column path by concatenating parent path with current key.
+
+    Args:
+        current_path (str): The current path prefix.
+        key (str): The current field's key.
+
+    Returns:
+        str: The full path.
+    """
+    return f"{current_path}.{key}" if current_path else key

datacontract/export/exporter.py

@@ -46,6 +46,7 @@ class ExportFormat(str, Enum):
     iceberg = "iceberg"
     custom = "custom"
     excel = "excel"
+    dqx = "dqx"
 
     @classmethod
     def get_supported_formats(cls):

datacontract/export/exporter_factory.py

@@ -197,6 +197,12 @@ def load_module_class(module_path, class_name):
     class_name="MarkdownExporter",
 )
 
+exporter_factory.register_lazy_exporter(
+    name=ExportFormat.dqx,
+    module_path="datacontract.export.dqx_converter",
+    class_name="DqxExporter",
+)
+
 exporter_factory.register_lazy_exporter(
     name=ExportFormat.iceberg, module_path="datacontract.export.iceberg_converter", class_name="IcebergExporter"
 )

datacontract/export/spark_converter.py

@@ -152,7 +152,7 @@ def to_spark_data_type(field: Field) -> types.DataType:
         return types.DateType()
     if field_type == "bytes":
         return types.BinaryType()
-    return types.StringType() # default if no condition is met
+    return types.StringType()  # default if no condition is met
 
 
 def print_schema(dtype: types.DataType) -> str: