Update date parsing (partially use isodate pkg)

isodate is already installed since it is a rdflib dependency

linkml_runtime/utils/metamodelcore.py

@@ -6,6 +6,7 @@
 from typing import Union, Optional, Tuple
 from urllib.parse import urlparse
 
+import isodate
 from rdflib import Literal, BNode, URIRef
 from rdflib.namespace import is_ncname
 from rdflib.term import Identifier as rdflib_Identifier
@@ -230,13 +231,10 @@ def __new__(cls, value: Union[str, datetime.time, datetime.datetime, Literal]) -
             if not isinstance(value, datetime.time):
                 value = datetime.time.fromisoformat(value)
             return datetime.time.fromisoformat(str(value)).isoformat()
-        except TypeError as e:
-            pass
-        except ValueError as e:
-            pass
-        if not is_strict():
-            return str(value)
-        raise e
+        except (TypeError, ValueError) as e:
+            if is_strict():
+                raise e
+        return str(value)
 
     @classmethod
     def is_valid(cls, value: Union[str, datetime.time, datetime.datetime, Literal]) -> bool:
@@ -260,15 +258,13 @@ def __new__(cls, value: Union[str, datetime.date, Literal]) -> str:
             value = value.value
         try:
             if not isinstance(value, datetime.date):
-                value = datetime.date.fromisoformat(str(value))
+                # value = datetime.date.fromisoformat(str(value))
+                value = isodate.parse_date(value)
             return value.isoformat()
-        except TypeError as e:
-            pass
-        except ValueError as e:
-            pass
-        if not is_strict():
-            return str(value)
-        raise e
+        except (TypeError, ValueError) as e:
+            if is_strict():
+                raise e
+        return str(value)
 
     @classmethod
     def is_valid(cls, value: Union[str, datetime.date, Literal]) -> bool:
@@ -279,7 +275,8 @@ def is_valid(cls, value: Union[str, datetime.date, Literal]) -> bool:
         if not re.match(r'^\d{4}-\d{2}-\d{2}$', value):
             return False
         try:
-            datetime.date.fromisoformat(str(value))
+            # datetime.date.fromisoformat(str(value))
+            value = isodate.parse_date(value)
         except ValueError:
             return False
         return True
@@ -294,15 +291,16 @@ def __new__(cls, value: Union[str, datetime.datetime, Literal]) -> str:
             value = value.value
         try:
             if not isinstance(value, datetime.datetime):
-                value = datetime.datetime.fromisoformat(value)      # Note that this handles non 'T' format as well
+                # value = datetime.datetime.fromisoformat(value)      # Note that this handles non 'T' format as well
+                if "T" in str(value):
+                    value = isodate.parse_datetime(value)
+                else:
+                    value = isodate.parse_datetime("T".join(value.strip().split(' ', 1)))
             return value.isoformat()
-        except TypeError as e:
-            pass
-        except ValueError as e:
-            pass
-        if not is_strict():
-            return str(value)
-        raise e
+        except (TypeError, ValueError) as e:
+            if is_strict():
+                raise e
+        return str(value)
 
     @classmethod
     def is_valid(cls, value: Union[str, datetime.datetime, Literal]) -> bool:
@@ -311,8 +309,14 @@ def is_valid(cls, value: Union[str, datetime.datetime, Literal]) -> bool:
         if isinstance(value, datetime.datetime):
             value = value.isoformat()
         try:
-            datetime.datetime.fromisoformat(value)
-        except ValueError:
+            # datetime.datetime.fromisoformat(value)
+            if "T" in str(value):
+                isodate.parse_datetime(value)
+            elif " " in value.strip():
+                isodate.parse_datetime("T".join(value.strip().split(' ', 1)))
+            else:
+                datetime.datetime.fromisoformat(value)
+        except (ValueError, TypeError):
             return False
         return True