coerce all parsed timestampts to UTC (#316)

ecoscope/io/earthranger_utils.py

@@ -41,7 +41,7 @@ def clean_time_cols(df):
     for col in time_cols:
         if col in df.columns:
             # convert x is not None to pd.isna(x) is False
-            df[col] = df[col].apply(lambda x: pd.to_datetime(parser.parse(x)) if not pd.isna(x) else None)
+            df[col] = df[col].apply(lambda x: pd.to_datetime(parser.parse(x), utc=True) if not pd.isna(x) else None)
     return df
 
 

tests/test_earthranger_utils.py

@@ -0,0 +1,53 @@
+import pytest
+
+import numpy as np
+import pandas as pd
+
+from ecoscope.io.earthranger_utils import clean_time_cols
+
+
+@pytest.fixture
+def df_with_times():
+    return pd.DataFrame(
+        data={
+            "time": [
+                "2023-01-30 11:26:13.805829-08:00",
+                "2023-09-27T06:16:46.158966",
+                "2023-09-27T06:16:46.23-07:00",
+                "2023-09-27T06:16:46.1589-07:00",
+                "2023-09-27T22:00:01.23-11:00",
+                "2023-09-27T06:16:46.00-07:00",
+                "2023-09-27T22:00:00.00-02:00",
+                pd.NA,
+            ]
+        },
+        index=["A", "B", "C", "D", "E", "F", "G", "H"],
+    )
+
+
+def test_clean_time_cols(df_with_times):
+    with pytest.raises(AttributeError):
+        df_with_times["time"].dt
+
+    cleaned = clean_time_cols(df_with_times)
+    assert pd.api.types.is_datetime64_ns_dtype(cleaned["time"])
+    # Check we have our dt accessor
+    df_with_times["time"].dt
+
+    expected_times = pd.arrays.DatetimeArray._from_sequence(
+        [
+            "2023-01-30 19:26:13.805829+00:00",
+            "2023-09-27 06:16:46.158966+00:00",
+            "2023-09-27 13:16:46.230000+00:00",
+            "2023-09-27 13:16:46.158900+00:00",
+            "2023-09-28 09:00:01.230000+00:00",
+            "2023-09-27 13:16:46+00:00",
+            "2023-09-28 00:00:00+00:00",
+        ]
+    )
+
+    # Since the parser resolves nan's to pd.NaT,
+    # and pd.NaT != pd.NaT
+    # check the nan separately from the array equality
+    assert np.array_equal(expected_times, cleaned["time"].array[:-1])
+    assert pd.isnull(cleaned["time"]["H"])