Merge pull request #183 from BIH-CEI/179-read-hierarchical-data

179 read hierarchical data

src/phenopacket_mapper/data_standards/__init__.py

@@ -4,14 +4,12 @@
 from .code_system import CodeSystem, SNOMED_CT, HPO, MONDO, OMIM, ORDO, LOINC
 from .code import Coding, CodeableConcept
 from .data_model import DataModel, DataField, DataModelInstance, DataFieldValue, DataSet, DataSection, OrGroup
-from . import data_models
 from .value_set import ValueSet
 
 __all__ = [
     "Cardinality",
     "Coding", "CodeableConcept",
     "DataModel", "DataField", "DataModelInstance", "DataFieldValue", "DataSet", "DataSection", "OrGroup",
-    "data_models",
     "CodeSystem",
     "SNOMED_CT", "HPO", "MONDO", "OMIM", "ORDO", "LOINC",
     "Date",

src/phenopacket_mapper/data_standards/cardinality.py

@@ -19,4 +19,36 @@ def __post_init__(self):
             raise ValueError(f"Parameter max must be a positive integer. (Not: {self.min})")
 
     def __str__(self):
-        return f"{self.min}..{self.max}"
+        return f"{self.min}..{self.max}"
+
+    # Singleton instances
+    _instances = {}
+
+    @classmethod
+    @property
+    def ZERO_TO_ONE(cls) -> 'Cardinality':
+        if 'ZERO_TO_ONE' not in cls._instances:
+            cls._instances['ZERO_TO_ONE'] = cls(0, 1)
+        return cls._instances['ZERO_TO_ONE']
+
+    @classmethod
+    @property
+    def ZERO_TO_N(cls) -> 'Cardinality':
+        if 'ZERO_TO_N' not in cls._instances:
+            cls._instances['ZERO_TO_N'] = cls(0, 'n')
+        return cls._instances['ZERO_TO_N']
+
+    @classmethod
+    @property
+    def ONE(cls) -> 'Cardinality':
+        if 'OPTIONAL' not in cls._instances:
+            cls._instances['ONE'] = cls(1, 1)
+        return cls._instances['ONE']
+
+    @classmethod
+    @property
+    def ONE_TO_N(cls) -> 'Cardinality':
+        if 'ONE_TO_N' not in cls._instances:
+            cls._instances['ONE_TO_N'] = cls(1, 'n')
+        return cls._instances['ONE_TO_N']
+