Move timedelta_to_float helper

and corresponding tests

Author: VeckoTheGecko

src/parcels/_core/particlefile.py

@@ -15,7 +15,7 @@
 
 import parcels
 from parcels._core.particle import _SAME_AS_FIELDSET_TIME_INTERVAL, ParticleClass
-from parcels.utils._helpers import timedelta_to_float
+from parcels._core.utils.time import timedelta_to_float
 
 if TYPE_CHECKING:
     from parcels._core.particle import Variable

src/parcels/_core/utils/time.py

@@ -144,3 +144,12 @@ def maybe_convert_python_timedelta_to_numpy(dt: timedelta | np.timedelta64) -> n
             return np.timedelta64(0, "s")
     except Exception as e:
         raise ValueError(f"Could not convert {dt!r} to np.timedelta64.") from e
+
+
+def timedelta_to_float(dt: float | timedelta | np.timedelta64) -> float:
+    """Convert a timedelta to a float in seconds."""
+    if isinstance(dt, timedelta):
+        return dt.total_seconds()
+    if isinstance(dt, np.timedelta64):
+        return float(dt / np.timedelta64(1, "s"))
+    return float(dt)

src/parcels/utils/_helpers.py

@@ -1,10 +1,7 @@
-from datetime import timedelta
-
-import numpy as np
 import pytest
 
 import parcels.tools._helpers as helpers
-from parcels.tools._helpers import deprecated, deprecated_made_private, timedelta_to_float
+from parcels.tools._helpers import deprecated, deprecated_made_private
 
 
 def test_format_list_items_multiline():
@@ -67,20 +64,3 @@ def some_function(x, y):
         some_function(1, 2)
 
     assert "deprecated::" in some_function.__doc__
-
-
-@pytest.mark.parametrize(
-    "input, expected",
-    [
-        (timedelta(days=1), 24 * 60 * 60),
-        (np.timedelta64(1, "D"), 24 * 60 * 60),
-        (3600.0, 3600.0),
-    ],
-)
-def test_timedelta_to_float(input, expected):
-    assert timedelta_to_float(input) == expected
-
-
-def test_timedelta_to_float_exceptions():
-    with pytest.raises((ValueError, TypeError)):
-        timedelta_to_float("invalid_type")

tests-v3/tools/test_helpers.py

@@ -8,7 +8,7 @@
 from hypothesis import given
 from hypothesis import strategies as st
 
-from parcels._core.utils.time import TimeInterval, maybe_convert_python_timedelta_to_numpy
+from parcels._core.utils.time import TimeInterval, maybe_convert_python_timedelta_to_numpy, timedelta_to_float
 
 calendar_strategy = st.sampled_from(
     [
@@ -198,3 +198,20 @@ def test_time_interval_intersection_different_calendars():
 def test_maybe_convert_python_timedelta_to_numpy(td, expected):
     result = maybe_convert_python_timedelta_to_numpy(td)
     assert result == expected
+
+
+@pytest.mark.parametrize(
+    "input, expected",
+    [
+        (timedelta(days=1), 24 * 60 * 60),
+        (np.timedelta64(1, "D"), 24 * 60 * 60),
+        (3600.0, 3600.0),
+    ],
+)
+def test_timedelta_to_float(input, expected):
+    assert timedelta_to_float(input) == expected
+
+
+def test_timedelta_to_float_exceptions():
+    with pytest.raises((ValueError, TypeError)):
+        timedelta_to_float("invalid_type")