REF/TST: share asfreq tests (#44219)

Author: jbrockmendel

pandas/tests/frame/methods/test_asfreq.py

@@ -1,12 +1,14 @@
 from datetime import datetime
 
 import numpy as np
+import pytest
 
 from pandas import (
     DataFrame,
     DatetimeIndex,
     Series,
     date_range,
+    period_range,
     to_datetime,
 )
 import pandas._testing as tm
@@ -15,41 +17,135 @@
 
 
 class TestAsFreq:
-    def test_asfreq_resample_set_correct_freq(self):
+    def test_asfreq2(self, frame_or_series):
+        ts = frame_or_series(
+            [0.0, 1.0, 2.0],
+            index=DatetimeIndex(
+                [
+                    datetime(2009, 10, 30),
+                    datetime(2009, 11, 30),
+                    datetime(2009, 12, 31),
+                ],
+                freq="BM",
+            ),
+        )
+
+        daily_ts = ts.asfreq("B")
+        monthly_ts = daily_ts.asfreq("BM")
+        tm.assert_equal(monthly_ts, ts)
+
+        daily_ts = ts.asfreq("B", method="pad")
+        monthly_ts = daily_ts.asfreq("BM")
+        tm.assert_equal(monthly_ts, ts)
+
+        daily_ts = ts.asfreq(offsets.BDay())
+        monthly_ts = daily_ts.asfreq(offsets.BMonthEnd())
+        tm.assert_equal(monthly_ts, ts)
+
+        result = ts[:0].asfreq("M")
+        assert len(result) == 0
+        assert result is not ts
+
+        if frame_or_series is Series:
+            daily_ts = ts.asfreq("D", fill_value=-1)
+            result = daily_ts.value_counts().sort_index()
+            expected = Series([60, 1, 1, 1], index=[-1.0, 2.0, 1.0, 0.0]).sort_index()
+            tm.assert_series_equal(result, expected)
+
+    def test_asfreq_datetimeindex_empty(self, frame_or_series):
+        # GH#14320
+        index = DatetimeIndex(["2016-09-29 11:00"])
+        expected = frame_or_series(index=index, dtype=object).asfreq("H")
+        result = frame_or_series([3], index=index.copy()).asfreq("H")
+        tm.assert_index_equal(expected.index, result.index)
+
+    @pytest.mark.parametrize("tz", ["US/Eastern", "dateutil/US/Eastern"])
+    def test_tz_aware_asfreq_smoke(self, tz, frame_or_series):
+        dr = date_range("2011-12-01", "2012-07-20", freq="D", tz=tz)
+
+        obj = frame_or_series(np.random.randn(len(dr)), index=dr)
+
+        # it works!
+        obj.asfreq("T")
+
+    def test_asfreq_normalize(self, frame_or_series):
+        rng = date_range("1/1/2000 09:30", periods=20)
+        norm = date_range("1/1/2000", periods=20)
+
+        vals = np.random.randn(20, 3)
+
+        obj = DataFrame(vals, index=rng)
+        expected = DataFrame(vals, index=norm)
+        if frame_or_series is Series:
+            obj = obj[0]
+            expected = expected[0]
+
+        result = obj.asfreq("D", normalize=True)
+        tm.assert_equal(result, expected)
+
+    def test_asfreq_keep_index_name(self, frame_or_series):
+        # GH#9854
+        index_name = "bar"
+        index = date_range("20130101", periods=20, name=index_name)
+        obj = DataFrame(list(range(20)), columns=["foo"], index=index)
+        if frame_or_series is Series:
+            obj = obj["foo"]
+
+        assert index_name == obj.index.name
+        assert index_name == obj.asfreq("10D").index.name
+
+    def test_asfreq_ts(self, frame_or_series):
+        index = period_range(freq="A", start="1/1/2001", end="12/31/2010")
+        obj = DataFrame(np.random.randn(len(index), 3), index=index)
+        if frame_or_series is Series:
+            obj = obj[0]
+
+        result = obj.asfreq("D", how="end")
+        exp_index = index.asfreq("D", how="end")
+        assert len(result) == len(obj)
+        tm.assert_index_equal(result.index, exp_index)
+
+        result = obj.asfreq("D", how="start")
+        exp_index = index.asfreq("D", how="start")
+        assert len(result) == len(obj)
+        tm.assert_index_equal(result.index, exp_index)
+
+    def test_asfreq_resample_set_correct_freq(self, frame_or_series):
         # GH#5613
         # we test if .asfreq() and .resample() set the correct value for .freq
-        df = DataFrame(
-            {"date": ["2012-01-01", "2012-01-02", "2012-01-03"], "col": [1, 2, 3]}
-        )
-        df = df.set_index(to_datetime(df.date))
+        dti = to_datetime(["2012-01-01", "2012-01-02", "2012-01-03"])
+        obj = DataFrame({"col": [1, 2, 3]}, index=dti)
+        if frame_or_series is Series:
+            obj = obj["col"]
 
         # testing the settings before calling .asfreq() and .resample()
-        assert df.index.freq is None
-        assert df.index.inferred_freq == "D"
+        assert obj.index.freq is None
+        assert obj.index.inferred_freq == "D"
 
         # does .asfreq() set .freq correctly?
-        assert df.asfreq("D").index.freq == "D"
+        assert obj.asfreq("D").index.freq == "D"
 
         # does .resample() set .freq correctly?
-        assert df.resample("D").asfreq().index.freq == "D"
+        assert obj.resample("D").asfreq().index.freq == "D"
+
+    def test_asfreq_empty(self, datetime_frame):
+        # test does not blow up on length-0 DataFrame
+        zero_length = datetime_frame.reindex([])
+        result = zero_length.asfreq("BM")
+        assert result is not zero_length
 
     def test_asfreq(self, datetime_frame):
         offset_monthly = datetime_frame.asfreq(offsets.BMonthEnd())
         rule_monthly = datetime_frame.asfreq("BM")
 
-        tm.assert_almost_equal(offset_monthly["A"], rule_monthly["A"])
+        tm.assert_frame_equal(offset_monthly, rule_monthly)
 
         filled = rule_monthly.asfreq("B", method="pad")  # noqa
         # TODO: actually check that this worked.
 
         # don't forget!
         filled_dep = rule_monthly.asfreq("B", method="pad")  # noqa
 
-        # test does not blow up on length-0 DataFrame
-        zero_length = datetime_frame.reindex([])
-        result = zero_length.asfreq("BM")
-        assert result is not zero_length
-
     def test_asfreq_datetimeindex(self):
         df = DataFrame(
             {"A": [1, 2, 3]},