8th day of python challenges 111-117

venv/lib/python3.6/site-packages/pandas/tests/series/test_asof.py

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+import numpy as np
+import pytest
+
+from pandas import Series, Timestamp, date_range, isna, notna, offsets
+import pandas.util.testing as tm
+
+
+class TestSeriesAsof:
+    def test_basic(self):
+
+        # array or list or dates
+        N = 50
+        rng = date_range("1/1/1990", periods=N, freq="53s")
+        ts = Series(np.random.randn(N), index=rng)
+        ts[15:30] = np.nan
+        dates = date_range("1/1/1990", periods=N * 3, freq="25s")
+
+        result = ts.asof(dates)
+        assert notna(result).all()
+        lb = ts.index[14]
+        ub = ts.index[30]
+
+        result = ts.asof(list(dates))
+        assert notna(result).all()
+        lb = ts.index[14]
+        ub = ts.index[30]
+
+        mask = (result.index >= lb) & (result.index < ub)
+        rs = result[mask]
+        assert (rs == ts[lb]).all()
+
+        val = result[result.index[result.index >= ub][0]]
+        assert ts[ub] == val
+
+    def test_scalar(self):
+
+        N = 30
+        rng = date_range("1/1/1990", periods=N, freq="53s")
+        ts = Series(np.arange(N), index=rng)
+        ts[5:10] = np.NaN
+        ts[15:20] = np.NaN
+
+        val1 = ts.asof(ts.index[7])
+        val2 = ts.asof(ts.index[19])
+
+        assert val1 == ts[4]
+        assert val2 == ts[14]
+
+        # accepts strings
+        val1 = ts.asof(str(ts.index[7]))
+        assert val1 == ts[4]
+
+        # in there
+        result = ts.asof(ts.index[3])
+        assert result == ts[3]
+
+        # no as of value
+        d = ts.index[0] - offsets.BDay()
+        assert np.isnan(ts.asof(d))
+
+    def test_with_nan(self):
+        # basic asof test
+        rng = date_range("1/1/2000", "1/2/2000", freq="4h")
+        s = Series(np.arange(len(rng)), index=rng)
+        r = s.resample("2h").mean()
+
+        result = r.asof(r.index)
+        expected = Series(
+            [0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6.0],
+            index=date_range("1/1/2000", "1/2/2000", freq="2h"),
+        )
+        tm.assert_series_equal(result, expected)
+
+        r.iloc[3:5] = np.nan
+        result = r.asof(r.index)
+        expected = Series(
+            [0, 0, 1, 1, 1, 1, 3, 3, 4, 4, 5, 5, 6.0],
+            index=date_range("1/1/2000", "1/2/2000", freq="2h"),
+        )
+        tm.assert_series_equal(result, expected)
+
+        r.iloc[-3:] = np.nan
+        result = r.asof(r.index)
+        expected = Series(
+            [0, 0, 1, 1, 1, 1, 3, 3, 4, 4, 4, 4, 4.0],
+            index=date_range("1/1/2000", "1/2/2000", freq="2h"),
+        )
+        tm.assert_series_equal(result, expected)
+
+    def test_periodindex(self):
+        from pandas import period_range, PeriodIndex
+
+        # array or list or dates
+        N = 50
+        rng = period_range("1/1/1990", periods=N, freq="H")
+        ts = Series(np.random.randn(N), index=rng)
+        ts[15:30] = np.nan
+        dates = date_range("1/1/1990", periods=N * 3, freq="37min")
+
+        result = ts.asof(dates)
+        assert notna(result).all()
+        lb = ts.index[14]
+        ub = ts.index[30]
+
+        result = ts.asof(list(dates))
+        assert notna(result).all()
+        lb = ts.index[14]
+        ub = ts.index[30]
+
+        pix = PeriodIndex(result.index.values, freq="H")
+        mask = (pix >= lb) & (pix < ub)
+        rs = result[mask]
+        assert (rs == ts[lb]).all()
+
+        ts[5:10] = np.nan
+        ts[15:20] = np.nan
+
+        val1 = ts.asof(ts.index[7])
+        val2 = ts.asof(ts.index[19])
+
+        assert val1 == ts[4]
+        assert val2 == ts[14]
+
+        # accepts strings
+        val1 = ts.asof(str(ts.index[7]))
+        assert val1 == ts[4]
+
+        # in there
+        assert ts.asof(ts.index[3]) == ts[3]
+
+        # no as of value
+        d = ts.index[0].to_timestamp() - offsets.BDay()
+        assert isna(ts.asof(d))
+
+    def test_errors(self):
+
+        s = Series(
+            [1, 2, 3],
+            index=[Timestamp("20130101"), Timestamp("20130103"), Timestamp("20130102")],
+        )
+
+        # non-monotonic
+        assert not s.index.is_monotonic
+        with pytest.raises(ValueError):
+            s.asof(s.index[0])
+
+        # subset with Series
+        N = 10
+        rng = date_range("1/1/1990", periods=N, freq="53s")
+        s = Series(np.random.randn(N), index=rng)
+        with pytest.raises(ValueError):
+            s.asof(s.index[0], subset="foo")
+
+    def test_all_nans(self):
+        # GH 15713
+        # series is all nans
+        result = Series([np.nan]).asof([0])
+        expected = Series([np.nan])
+        tm.assert_series_equal(result, expected)
+
+        # testing non-default indexes
+        N = 50
+        rng = date_range("1/1/1990", periods=N, freq="53s")
+
+        dates = date_range("1/1/1990", periods=N * 3, freq="25s")
+        result = Series(np.nan, index=rng).asof(dates)
+        expected = Series(np.nan, index=dates)
+        tm.assert_series_equal(result, expected)
+
+        # testing scalar input
+        date = date_range("1/1/1990", periods=N * 3, freq="25s")[0]
+        result = Series(np.nan, index=rng).asof(date)
+        assert isna(result)
+
+        # test name is propagated
+        result = Series(np.nan, index=[1, 2, 3, 4], name="test").asof([4, 5])
+        expected = Series(np.nan, index=[4, 5], name="test")
+        tm.assert_series_equal(result, expected)