8th day of python challenges 111-117

venv/lib/python3.6/site-packages/pandas/tests/tslibs/test_conversion.py

@@ -0,0 +1,100 @@
+from datetime import datetime
+
+import numpy as np
+import pytest
+from pytz import UTC
+
+from pandas._libs.tslib import iNaT
+from pandas._libs.tslibs import conversion, timezones, tzconversion
+
+from pandas import Timestamp, date_range
+import pandas.util.testing as tm
+
+
+def _compare_utc_to_local(tz_didx):
+    def f(x):
+        return conversion.tz_convert_single(x, UTC, tz_didx.tz)
+
+    result = tzconversion.tz_convert(tz_didx.asi8, UTC, tz_didx.tz)
+    expected = np.vectorize(f)(tz_didx.asi8)
+
+    tm.assert_numpy_array_equal(result, expected)
+
+
+def _compare_local_to_utc(tz_didx, utc_didx):
+    def f(x):
+        return conversion.tz_convert_single(x, tz_didx.tz, UTC)
+
+    result = tzconversion.tz_convert(utc_didx.asi8, tz_didx.tz, UTC)
+    expected = np.vectorize(f)(utc_didx.asi8)
+
+    tm.assert_numpy_array_equal(result, expected)
+
+
+def test_tz_convert_single_matches_tz_convert_hourly(tz_aware_fixture):
+    tz = tz_aware_fixture
+    tz_didx = date_range("2014-03-01", "2015-01-10", freq="H", tz=tz)
+    utc_didx = date_range("2014-03-01", "2015-01-10", freq="H")
+
+    _compare_utc_to_local(tz_didx)
+    _compare_local_to_utc(tz_didx, utc_didx)
+
+
+@pytest.mark.parametrize("freq", ["D", "A"])
+def test_tz_convert_single_matches_tz_convert(tz_aware_fixture, freq):
+    tz = tz_aware_fixture
+    tz_didx = date_range("2000-01-01", "2020-01-01", freq=freq, tz=tz)
+    utc_didx = date_range("2000-01-01", "2020-01-01", freq=freq)
+
+    _compare_utc_to_local(tz_didx)
+    _compare_local_to_utc(tz_didx, utc_didx)
+
+
+@pytest.mark.parametrize(
+    "arr",
+    [
+        pytest.param(np.array([], dtype=np.int64), id="empty"),
+        pytest.param(np.array([iNaT], dtype=np.int64), id="all_nat"),
+    ],
+)
+def test_tz_convert_corner(arr):
+    result = tzconversion.tz_convert(
+        arr, timezones.maybe_get_tz("US/Eastern"), timezones.maybe_get_tz("Asia/Tokyo")
+    )
+    tm.assert_numpy_array_equal(result, arr)
+
+
+@pytest.mark.parametrize("copy", [True, False])
+@pytest.mark.parametrize("dtype", ["M8[ns]", "M8[s]"])
+def test_length_zero_copy(dtype, copy):
+    arr = np.array([], dtype=dtype)
+    result = conversion.ensure_datetime64ns(arr, copy=copy)
+    assert result.base is (None if copy else arr)
+
+
+class SubDatetime(datetime):
+    pass
+
+
+@pytest.mark.parametrize(
+    "dt, expected",
+    [
+        pytest.param(
+            Timestamp("2000-01-01"), Timestamp("2000-01-01", tz=UTC), id="timestamp"
+        ),
+        pytest.param(
+            datetime(2000, 1, 1), datetime(2000, 1, 1, tzinfo=UTC), id="datetime"
+        ),
+        pytest.param(
+            SubDatetime(2000, 1, 1),
+            SubDatetime(2000, 1, 1, tzinfo=UTC),
+            id="subclassed_datetime",
+        ),
+    ],
+)
+def test_localize_pydatetime_dt_types(dt, expected):
+    # GH 25851
+    # ensure that subclassed datetime works with
+    # localize_pydatetime
+    result = conversion.localize_pydatetime(dt, UTC)
+    assert result == expected