Use python dateutil package to parse iso strings

Author: Val Brodsky

labelbox/schema/data_row_metadata.py

@@ -5,10 +5,11 @@
 from itertools import chain
 from typing import List, Optional, Dict, Union, Callable, Type, Any, Generator
 
+from dateutil.parser import isoparse
 from pydantic import BaseModel, conlist, constr
 
 from labelbox.schema.ontology import SchemaId
-from labelbox.utils import _CamelCaseMixin, format_iso_datetime
+from labelbox.utils import _CamelCaseMixin, format_iso_datetime, format_iso_default_utc
 
 
 class DataRowMetadataKind(Enum):
@@ -466,7 +467,7 @@ def parse_metadata_fields(
                                              value=schema.uid)
             elif schema.kind == DataRowMetadataKind.datetime:
                 field = DataRowMetadataField(schema_id=schema.uid,
-                                             value=datetime.fromisoformat(
+                                             value=format_iso_default_utc(
                                                  f["value"]))
             else:
                 field = DataRowMetadataField(schema_id=schema.uid,
@@ -838,7 +839,7 @@ def _validate_parse_number(
 def _validate_parse_datetime(
         field: DataRowMetadataField) -> List[Dict[str, Union[SchemaId, str]]]:
     if isinstance(field.value, str):
-        field.value = datetime.fromisoformat(field.value)
+        field.value = format_iso_default_utc(field.value)
     elif not isinstance(field.value, datetime):
         raise TypeError(
             f"Value for datetime fields must be either a string or datetime object. Found {type(field.value)}"

labelbox/utils.py

@@ -1,10 +1,18 @@
 import datetime
 import re
+
+import datetime
+from dateutil.tz import tzoffset
+from dateutil.parser import isoparse as dateutil_parse
+from dateutil.utils import default_tzinfo
+
 from urllib.parse import urlparse
 from pydantic import BaseModel
 
 UPPERCASE_COMPONENTS = ['uri', 'rgb']
 ISO_DATETIME_FORMAT = '%Y-%m-%dT%H:%M:%SZ'
+DFLT_TZ = tzoffset("UTC", 0000)
+
 
 
 def _convert(s, sep, title):
@@ -80,4 +88,13 @@ def format_iso_datetime(dt: datetime.datetime) -> str:
     Formats a datetime object into the format: 2011-11-04T00:05:23Z
     Note that datetime.isoformat() outputs 2011-11-04T00:05:23+00:00
     """
-    return dt.strftime(ISO_DATETIME_FORMAT)
+    return dt.strftime(ISO_DATETIME_FORMAT)
+
+
+def format_iso_default_utc(date_string: str) -> datetime.datetime:
+    """
+    Converts a string even if offset is missing: 2011-11-04T00:05:23Z or 2011-11-04T00:05:23+00:00 or 2011-11-04T00:05:23
+    to a datetime object.
+    For missing offsets, the default offset is UTC.
+    """
+    return default_tzinfo(dateutil_parse(date_string), DFLT_TZ)

tests/integration/test_data_row_metadata.py

@@ -445,7 +445,7 @@ def test_delete_schema(mdo):
 
 
 @pytest.mark.parametrize('datetime_str',
-                         ['2011-11-04T00:05:23Z', '2011-05-07T14:34:14+00:00'])
+                         ['2011-11-04T00:05:23Z', '2011-11-04T00:05:23+00:00'])
 def test_upsert_datarow_date_metadata(data_row, mdo, datetime_str):
     metadata = [
         DataRowMetadata(data_row_id=data_row.uid,
@@ -458,11 +458,11 @@ def test_upsert_datarow_date_metadata(data_row, mdo, datetime_str):
     assert len(errors) == 0
 
     metadata = mdo.bulk_export([data_row.uid])
-    assert metadata[0].fields[0].value == datetime.fromisoformat(datetime_str)
+    assert f"{metadata[0].fields[0].value}" == "2011-11-04 00:05:23+00:00"
 
 
 @pytest.mark.parametrize('datetime_str',
-                         ['2011-11-04T00:05:23Z', '2011-05-07T14:34:14+00:00'])
+                         ['2011-11-04T00:05:23Z', '2011-11-04T00:05:23+00:00'])
 def test_create_data_row_with_metadata(dataset, image_url, datetime_str):
     client = dataset.client
     assert len(list(dataset.data_rows())) == 0
@@ -475,5 +475,4 @@ def test_create_data_row_with_metadata(dataset, image_url, datetime_str):
                                        metadata_fields=metadata_fields)
 
     retrieved_data_row = client.get_data_row(data_row.uid)
-    assert retrieved_data_row.metadata[0].value == datetime.fromisoformat(
-        datetime_str)
+    assert f"{retrieved_data_row.metadata[0].value}" == "2011-11-04 00:05:23+00:00"