Cleanup test_coding_times.py (#9223)

* Cleanup test_coding_times

* Update test_coding_times.py

Author: Illviljan

xarray/tests/test_coding_times.py

@@ -14,20 +14,25 @@
     Dataset,
     Variable,
     cftime_range,
-    coding,
     conventions,
     date_range,
     decode_cf,
 )
+from xarray.coding.times import _STANDARD_CALENDARS as _STANDARD_CALENDARS_UNSORTED
 from xarray.coding.times import (
+    CFDatetimeCoder,
     _encode_datetime_with_cftime,
+    _netcdf_to_numpy_timeunit,
     _numpy_to_netcdf_timeunit,
     _should_cftime_be_used,
     cftime_to_nptime,
     decode_cf_datetime,
     decode_cf_timedelta,
     encode_cf_datetime,
     encode_cf_timedelta,
+    format_cftime_datetime,
+    infer_datetime_units,
+    infer_timedelta_units,
     to_timedelta_unboxed,
 )
 from xarray.coding.variables import SerializationWarning
@@ -53,11 +58,9 @@
     "all_leap",
     "366_day",
 }
-_ALL_CALENDARS = sorted(
-    _NON_STANDARD_CALENDARS_SET.union(coding.times._STANDARD_CALENDARS)
-)
+_STANDARD_CALENDARS = sorted(_STANDARD_CALENDARS_UNSORTED)
+_ALL_CALENDARS = sorted(_NON_STANDARD_CALENDARS_SET.union(_STANDARD_CALENDARS))
 _NON_STANDARD_CALENDARS = sorted(_NON_STANDARD_CALENDARS_SET)
-_STANDARD_CALENDARS = sorted(coding.times._STANDARD_CALENDARS)
 _CF_DATETIME_NUM_DATES_UNITS = [
     (np.arange(10), "days since 2000-01-01"),
     (np.arange(10).astype("float64"), "days since 2000-01-01"),
@@ -130,7 +133,7 @@ def test_cf_datetime(num_dates, units, calendar) -> None:
 
     with warnings.catch_warnings():
         warnings.filterwarnings("ignore", "Unable to decode time axis")
-        actual = coding.times.decode_cf_datetime(num_dates, units, calendar)
+        actual = decode_cf_datetime(num_dates, units, calendar)
 
     abs_diff = np.asarray(abs(actual - expected)).ravel()
     abs_diff = pd.to_timedelta(abs_diff.tolist()).to_numpy()
@@ -139,17 +142,15 @@ def test_cf_datetime(num_dates, units, calendar) -> None:
     # we could do this check with near microsecond accuracy:
     # https://github.com/Unidata/netcdf4-python/issues/355
     assert (abs_diff <= np.timedelta64(1, "s")).all()
-    encoded, _, _ = coding.times.encode_cf_datetime(actual, units, calendar)
+    encoded, _, _ = encode_cf_datetime(actual, units, calendar)
 
-    assert_array_equal(num_dates, np.around(encoded, 1))
+    assert_array_equal(num_dates, np.round(encoded, 1))
     if hasattr(num_dates, "ndim") and num_dates.ndim == 1 and "1000" not in units:
         # verify that wrapping with a pandas.Index works
         # note that it *does not* currently work to put
         # non-datetime64 compatible dates into a pandas.Index
-        encoded, _, _ = coding.times.encode_cf_datetime(
-            pd.Index(actual), units, calendar
-        )
-        assert_array_equal(num_dates, np.around(encoded, 1))
+        encoded, _, _ = encode_cf_datetime(pd.Index(actual), units, calendar)
+        assert_array_equal(num_dates, np.round(encoded, 1))
 
 
 @requires_cftime
@@ -169,7 +170,7 @@ def test_decode_cf_datetime_overflow() -> None:
     for i, day in enumerate(days):
         with warnings.catch_warnings():
             warnings.filterwarnings("ignore", "Unable to decode time axis")
-            result = coding.times.decode_cf_datetime(day, units)
+            result = decode_cf_datetime(day, units)
         assert result == expected[i]
 
 
@@ -178,7 +179,7 @@ def test_decode_cf_datetime_non_standard_units() -> None:
     # netCDFs from madis.noaa.gov use this format for their time units
     # they cannot be parsed by cftime, but pd.Timestamp works
     units = "hours since 1-1-1970"
-    actual = coding.times.decode_cf_datetime(np.arange(100), units)
+    actual = decode_cf_datetime(np.arange(100), units)
     assert_array_equal(actual, expected)
 
 
@@ -193,7 +194,7 @@ def test_decode_cf_datetime_non_iso_strings() -> None:
         (np.arange(100), "hours since 2000-01-01 0:00"),
     ]
     for num_dates, units in cases:
-        actual = coding.times.decode_cf_datetime(num_dates, units)
+        actual = decode_cf_datetime(num_dates, units)
         abs_diff = abs(actual - expected.values)
         # once we no longer support versions of netCDF4 older than 1.1.5,
         # we could do this check with near microsecond accuracy:
@@ -212,7 +213,7 @@ def test_decode_standard_calendar_inside_timestamp_range(calendar) -> None:
     expected = times.values
     expected_dtype = np.dtype("M8[ns]")
 
-    actual = coding.times.decode_cf_datetime(time, units, calendar=calendar)
+    actual = decode_cf_datetime(time, units, calendar=calendar)
     assert actual.dtype == expected_dtype
     abs_diff = abs(actual - expected)
     # once we no longer support versions of netCDF4 older than 1.1.5,
@@ -235,9 +236,7 @@ def test_decode_non_standard_calendar_inside_timestamp_range(calendar) -> None:
     )
     expected_dtype = np.dtype("O")
 
-    actual = coding.times.decode_cf_datetime(
-        non_standard_time, units, calendar=calendar
-    )
+    actual = decode_cf_datetime(non_standard_time, units, calendar=calendar)
     assert actual.dtype == expected_dtype
     abs_diff = abs(actual - expected)
     # once we no longer support versions of netCDF4 older than 1.1.5,
@@ -264,7 +263,7 @@ def test_decode_dates_outside_timestamp_range(calendar) -> None:
 
     with warnings.catch_warnings():
         warnings.filterwarnings("ignore", "Unable to decode time axis")
-        actual = coding.times.decode_cf_datetime(time, units, calendar=calendar)
+        actual = decode_cf_datetime(time, units, calendar=calendar)
     assert all(isinstance(value, expected_date_type) for value in actual)
     abs_diff = abs(actual - expected)
     # once we no longer support versions of netCDF4 older than 1.1.5,
@@ -282,7 +281,7 @@ def test_decode_standard_calendar_single_element_inside_timestamp_range(
     for num_time in [735368, [735368], [[735368]]]:
         with warnings.catch_warnings():
             warnings.filterwarnings("ignore", "Unable to decode time axis")
-            actual = coding.times.decode_cf_datetime(num_time, units, calendar=calendar)
+            actual = decode_cf_datetime(num_time, units, calendar=calendar)
         assert actual.dtype == np.dtype("M8[ns]")
 
 
@@ -295,7 +294,7 @@ def test_decode_non_standard_calendar_single_element_inside_timestamp_range(
     for num_time in [735368, [735368], [[735368]]]:
         with warnings.catch_warnings():
             warnings.filterwarnings("ignore", "Unable to decode time axis")
-            actual = coding.times.decode_cf_datetime(num_time, units, calendar=calendar)
+            actual = decode_cf_datetime(num_time, units, calendar=calendar)
         assert actual.dtype == np.dtype("O")
 
 
@@ -309,9 +308,7 @@ def test_decode_single_element_outside_timestamp_range(calendar) -> None:
         for num_time in [days, [days], [[days]]]:
             with warnings.catch_warnings():
                 warnings.filterwarnings("ignore", "Unable to decode time axis")
-                actual = coding.times.decode_cf_datetime(
-                    num_time, units, calendar=calendar
-                )
+                actual = decode_cf_datetime(num_time, units, calendar=calendar)
 
             expected = cftime.num2date(
                 days, units, calendar, only_use_cftime_datetimes=True
@@ -338,7 +335,7 @@ def test_decode_standard_calendar_multidim_time_inside_timestamp_range(
     expected1 = times1.values
     expected2 = times2.values
 
-    actual = coding.times.decode_cf_datetime(mdim_time, units, calendar=calendar)
+    actual = decode_cf_datetime(mdim_time, units, calendar=calendar)
     assert actual.dtype == np.dtype("M8[ns]")
 
     abs_diff1 = abs(actual[:, 0] - expected1)
@@ -379,7 +376,7 @@ def test_decode_nonstandard_calendar_multidim_time_inside_timestamp_range(
 
     expected_dtype = np.dtype("O")
 
-    actual = coding.times.decode_cf_datetime(mdim_time, units, calendar=calendar)
+    actual = decode_cf_datetime(mdim_time, units, calendar=calendar)
 
     assert actual.dtype == expected_dtype
     abs_diff1 = abs(actual[:, 0] - expected1)
@@ -412,7 +409,7 @@ def test_decode_multidim_time_outside_timestamp_range(calendar) -> None:
 
     with warnings.catch_warnings():
         warnings.filterwarnings("ignore", "Unable to decode time axis")
-        actual = coding.times.decode_cf_datetime(mdim_time, units, calendar=calendar)
+        actual = decode_cf_datetime(mdim_time, units, calendar=calendar)
 
     assert actual.dtype == np.dtype("O")
 
@@ -435,7 +432,7 @@ def test_decode_non_standard_calendar_single_element(calendar, num_time) -> None
 
     units = "days since 0001-01-01"
 
-    actual = coding.times.decode_cf_datetime(num_time, units, calendar=calendar)
+    actual = decode_cf_datetime(num_time, units, calendar=calendar)
 
     expected = np.asarray(
         cftime.num2date(num_time, units, calendar, only_use_cftime_datetimes=True)
@@ -460,9 +457,7 @@ def test_decode_360_day_calendar() -> None:
 
         with warnings.catch_warnings(record=True) as w:
             warnings.simplefilter("always")
-            actual = coding.times.decode_cf_datetime(
-                num_times, units, calendar=calendar
-            )
+            actual = decode_cf_datetime(num_times, units, calendar=calendar)
             assert len(w) == 0
 
         assert actual.dtype == np.dtype("O")
@@ -476,8 +471,8 @@ def test_decode_abbreviation() -> None:
 
     val = np.array([1586628000000.0])
     units = "msecs since 1970-01-01T00:00:00Z"
-    actual = coding.times.decode_cf_datetime(val, units)
-    expected = coding.times.cftime_to_nptime(cftime.num2date(val, units))
+    actual = decode_cf_datetime(val, units)
+    expected = cftime_to_nptime(cftime.num2date(val, units))
     assert_array_equal(actual, expected)
 
 
@@ -498,7 +493,7 @@ def test_decode_abbreviation() -> None:
 def test_cf_datetime_nan(num_dates, units, expected_list) -> None:
     with warnings.catch_warnings():
         warnings.filterwarnings("ignore", "All-NaN")
-        actual = coding.times.decode_cf_datetime(num_dates, units)
+        actual = decode_cf_datetime(num_dates, units)
     # use pandas because numpy will deprecate timezone-aware conversions
     expected = pd.to_datetime(expected_list).to_numpy(dtype="datetime64[ns]")
     assert_array_equal(expected, actual)
@@ -510,7 +505,7 @@ def test_decoded_cf_datetime_array_2d() -> None:
     variable = Variable(
         ("x", "y"), np.array([[0, 1], [2, 3]]), {"units": "days since 2000-01-01"}
     )
-    result = coding.times.CFDatetimeCoder().decode(variable)
+    result = CFDatetimeCoder().decode(variable)
     assert result.dtype == "datetime64[ns]"
     expected = pd.date_range("2000-01-01", periods=4).values.reshape(2, 2)
     assert_array_equal(np.asarray(result), expected)
@@ -531,7 +526,7 @@ def test_decoded_cf_datetime_array_2d() -> None:
 def test_infer_datetime_units(freq, units) -> None:
     dates = pd.date_range("2000", periods=2, freq=freq)
     expected = f"{units} since 2000-01-01 00:00:00"
-    assert expected == coding.times.infer_datetime_units(dates)
+    assert expected == infer_datetime_units(dates)
 
 
 @pytest.mark.parametrize(
@@ -549,7 +544,7 @@ def test_infer_datetime_units(freq, units) -> None:
     ],
 )
 def test_infer_datetime_units_with_NaT(dates, expected) -> None:
-    assert expected == coding.times.infer_datetime_units(dates)
+    assert expected == infer_datetime_units(dates)
 
 
 _CFTIME_DATETIME_UNITS_TESTS = [
@@ -573,7 +568,7 @@ def test_infer_datetime_units_with_NaT(dates, expected) -> None:
 def test_infer_cftime_datetime_units(calendar, date_args, expected) -> None:
     date_type = _all_cftime_date_types()[calendar]
     dates = [date_type(*args) for args in date_args]
-    assert expected == coding.times.infer_datetime_units(dates)
+    assert expected == infer_datetime_units(dates)
 
 
 @pytest.mark.filterwarnings("ignore:Timedeltas can't be serialized faithfully")
@@ -600,18 +595,18 @@ def test_cf_timedelta(timedeltas, units, numbers) -> None:
     numbers = np.array(numbers)
 
     expected = numbers
-    actual, _ = coding.times.encode_cf_timedelta(timedeltas, units)
+    actual, _ = encode_cf_timedelta(timedeltas, units)
     assert_array_equal(expected, actual)
     assert expected.dtype == actual.dtype
 
     if units is not None:
         expected = timedeltas
-        actual = coding.times.decode_cf_timedelta(numbers, units)
+        actual = decode_cf_timedelta(numbers, units)
         assert_array_equal(expected, actual)
         assert expected.dtype == actual.dtype
 
     expected = np.timedelta64("NaT", "ns")
-    actual = coding.times.decode_cf_timedelta(np.array(np.nan), "days")
+    actual = decode_cf_timedelta(np.array(np.nan), "days")
     assert_array_equal(expected, actual)
 
 
@@ -622,7 +617,7 @@ def test_cf_timedelta_2d() -> None:
     timedeltas = np.atleast_2d(to_timedelta_unboxed(["1D", "2D", "3D"]))
     expected = timedeltas
 
-    actual = coding.times.decode_cf_timedelta(numbers, units)
+    actual = decode_cf_timedelta(numbers, units)
     assert_array_equal(expected, actual)
     assert expected.dtype == actual.dtype
 
@@ -637,7 +632,7 @@ def test_cf_timedelta_2d() -> None:
     ],
 )
 def test_infer_timedelta_units(deltas, expected) -> None:
-    assert expected == coding.times.infer_timedelta_units(deltas)
+    assert expected == infer_timedelta_units(deltas)
 
 
 @requires_cftime
@@ -653,7 +648,7 @@ def test_infer_timedelta_units(deltas, expected) -> None:
 def test_format_cftime_datetime(date_args, expected) -> None:
     date_types = _all_cftime_date_types()
     for date_type in date_types.values():
-        result = coding.times.format_cftime_datetime(date_type(*date_args))
+        result = format_cftime_datetime(date_type(*date_args))
         assert result == expected
 
 
@@ -1008,7 +1003,7 @@ def test_decode_ambiguous_time_warns(calendar) -> None:
 
     # we don't decode non-standard calendards with
     # pandas so expect no warning will be emitted
-    is_standard_calendar = calendar in coding.times._STANDARD_CALENDARS
+    is_standard_calendar = calendar in _STANDARD_CALENDARS
 
     dates = [1, 2, 3]
     units = "days since 1-1-1"
@@ -1043,9 +1038,9 @@ def test_encode_cf_datetime_defaults_to_correct_dtype(
         pytest.skip("Nanosecond frequency is not valid for cftime dates.")
     times = date_range("2000", periods=3, freq=freq)
     units = f"{encoding_units} since 2000-01-01"
-    encoded, _units, _ = coding.times.encode_cf_datetime(times, units)
+    encoded, _units, _ = encode_cf_datetime(times, units)
 
-    numpy_timeunit = coding.times._netcdf_to_numpy_timeunit(encoding_units)
+    numpy_timeunit = _netcdf_to_numpy_timeunit(encoding_units)
     encoding_units_as_timedelta = np.timedelta64(1, numpy_timeunit)
     if pd.to_timedelta(1, freq) >= encoding_units_as_timedelta:
         assert encoded.dtype == np.int64
@@ -1202,7 +1197,7 @@ def test_decode_float_datetime():
 def test_scalar_unit() -> None:
     # test that a scalar units (often NaN when using to_netcdf) does not raise an error
     variable = Variable(("x", "y"), np.array([[0, 1], [2, 3]]), {"units": np.nan})
-    result = coding.times.CFDatetimeCoder().decode(variable)
+    result = CFDatetimeCoder().decode(variable)
     assert np.isnan(result.attrs["units"])