TST: tz_localize/tz_convert unclear test assertions (#37498)

Author: jbrockmendel

pandas/tests/frame/methods/test_tz_convert.py

@@ -1,7 +1,7 @@
 import numpy as np
 import pytest
 
-from pandas import DataFrame, Index, MultiIndex, date_range
+from pandas import DataFrame, Index, MultiIndex, Series, date_range
 import pandas._testing as tm
 
 
@@ -88,3 +88,19 @@ def test_tz_convert_and_localize(self, fn):
         with pytest.raises(ValueError, match="not valid"):
             df = DataFrame(index=l0)
             df = getattr(df, fn)("US/Pacific", level=1)
+
+    @pytest.mark.parametrize("klass", [Series, DataFrame])
+    @pytest.mark.parametrize("copy", [True, False])
+    def test_tz_convert_copy_inplace_mutate(self, copy, klass):
+        # GH#6326
+        obj = klass(
+            np.arange(0, 5),
+            index=date_range("20131027", periods=5, freq="1H", tz="Europe/Berlin"),
+        )
+        orig = obj.copy()
+        result = obj.tz_convert("UTC", copy=copy)
+        expected = klass(np.arange(0, 5), index=obj.index.tz_convert("UTC"))
+        tm.assert_equal(result, expected)
+        tm.assert_equal(obj, orig)
+        assert result.index is not obj.index
+        assert result is not obj

pandas/tests/frame/methods/test_tz_localize.py

@@ -1,4 +1,7 @@
-from pandas import DataFrame, date_range
+import numpy as np
+import pytest
+
+from pandas import DataFrame, Series, date_range
 import pandas._testing as tm
 
 
@@ -19,3 +22,21 @@ def test_frame_tz_localize(self):
         result = df.tz_localize("utc", axis=1)
         assert result.columns.tz.zone == "UTC"
         tm.assert_frame_equal(result, expected.T)
+
+    @pytest.mark.parametrize("klass", [Series, DataFrame])
+    @pytest.mark.parametrize("copy", [True, False])
+    def test_tz_localize_copy_inplace_mutate(self, copy, klass):
+        # GH#6326
+        obj = klass(
+            np.arange(0, 5), index=date_range("20131027", periods=5, freq="1H", tz=None)
+        )
+        orig = obj.copy()
+        result = obj.tz_localize("UTC", copy=copy)
+        expected = klass(
+            np.arange(0, 5),
+            index=date_range("20131027", periods=5, freq="1H", tz="UTC"),
+        )
+        tm.assert_equal(result, expected)
+        tm.assert_equal(obj, orig)
+        assert result.index is not obj.index
+        assert result is not obj

pandas/tests/series/test_constructors.py

@@ -1,6 +1,7 @@
 from collections import OrderedDict
 from datetime import datetime, timedelta
 
+from dateutil.tz import tzoffset
 import numpy as np
 import numpy.ma as ma
 import pytest
@@ -1588,6 +1589,20 @@ def test_constructor_dict_timedelta_index(self):
         )
         tm.assert_series_equal(result, expected)
 
+    def test_constructor_infer_index_tz(self):
+        values = [188.5, 328.25]
+        tzinfo = tzoffset(None, 7200)
+        index = [
+            datetime(2012, 5, 11, 11, tzinfo=tzinfo),
+            datetime(2012, 5, 11, 12, tzinfo=tzinfo),
+        ]
+        series = Series(data=values, index=index)
+
+        assert series.index.tz == tzinfo
+
+        # it works! GH#2443
+        repr(series.index[0])
+
 
 class TestSeriesConstructorIndexCoercion:
     def test_series_constructor_datetimelike_index_coercion(self):