CLN: Replace DataFrame() with empty_frame() in tests

pandas/tests/frame/indexing/test_indexing.py

@@ -44,7 +44,7 @@ def test_get(self, float_frame):
     @pytest.mark.parametrize(
         "df",
         [
-            DataFrame(),
+            empty_frame(),
             DataFrame(columns=list("AB")),
             DataFrame(columns=list("AB"), index=range(3)),
         ],
@@ -842,7 +842,7 @@ def test_setitem_with_empty_listlike(self):
 
     def test_setitem_scalars_no_index(self):
         # GH16823 / 17894
-        df = DataFrame()
+        df = empty_frame()
         df["foo"] = 1
         expected = DataFrame(columns=["foo"]).astype(np.int64)
         tm.assert_frame_equal(df, expected)
@@ -1669,7 +1669,7 @@ def test_reindex_subclass(self):
         class MyDataFrame(DataFrame):
             pass
 
-        expected = DataFrame()
+        expected = empty_frame()
         df = MyDataFrame()
         result = df.reindex_like(expected)
 

pandas/tests/frame/indexing/test_insert.py

@@ -58,7 +58,7 @@ def test_insert_column_bug_4032(self):
 
     def test_insert_with_columns_dups(self):
         # GH#14291
-        df = DataFrame()
+        df = empty_frame()
         df.insert(0, "A", ["g", "h", "i"], allow_duplicates=True)
         df.insert(0, "A", ["d", "e", "f"], allow_duplicates=True)
         df.insert(0, "A", ["a", "b", "c"], allow_duplicates=True)

pandas/tests/frame/methods/test_append.py

@@ -9,7 +9,7 @@
 class TestDataFrameAppend:
     def test_append_empty_list(self):
         # GH 28769
-        df = DataFrame()
+        df = empty_frame()
         result = df.append([])
         expected = df
         tm.assert_frame_equal(result, expected)
@@ -96,29 +96,29 @@ def test_append_missing_cols(self):
     def test_append_empty_dataframe(self):
 
         # Empty df append empty df
-        df1 = DataFrame()
-        df2 = DataFrame()
+        df1 = empty_frame()
+        df2 = empty_frame()
         result = df1.append(df2)
         expected = df1.copy()
         tm.assert_frame_equal(result, expected)
 
         # Non-empty df append empty df
         df1 = DataFrame(np.random.randn(5, 2))
-        df2 = DataFrame()
+        df2 = empty_frame()
         result = df1.append(df2)
         expected = df1.copy()
         tm.assert_frame_equal(result, expected)
 
         # Empty df with columns append empty df
         df1 = DataFrame(columns=["bar", "foo"])
-        df2 = DataFrame()
+        df2 = empty_frame()
         result = df1.append(df2)
         expected = df1.copy()
         tm.assert_frame_equal(result, expected)
 
         # Non-Empty df with columns append empty df
         df1 = DataFrame(np.random.randn(5, 2), columns=["bar", "foo"])
-        df2 = DataFrame()
+        df2 = empty_frame()
         result = df1.append(df2)
         expected = df1.copy()
         tm.assert_frame_equal(result, expected)
@@ -130,7 +130,7 @@ def test_append_dtypes(self):
         # can sometimes infer the correct type
 
         df1 = DataFrame({"bar": Timestamp("20130101")}, index=range(5))
-        df2 = DataFrame()
+        df2 = empty_frame()
         result = df1.append(df2)
         expected = df1.copy()
         tm.assert_frame_equal(result, expected)

pandas/tests/frame/methods/test_combine_first.py

@@ -73,7 +73,7 @@ def test_combine_first(self, float_frame):
         comb = float_frame.combine_first(DataFrame())
         tm.assert_frame_equal(comb, float_frame)
 
-        comb = DataFrame().combine_first(float_frame)
+        comb = empty_frame().combine_first(float_frame)
         tm.assert_frame_equal(comb, float_frame)
 
         comb = float_frame.combine_first(DataFrame(index=["faz", "boo"]))

pandas/tests/frame/methods/test_count.py

@@ -5,7 +5,7 @@
 class TestDataFrameCount:
     def test_count(self):
         # corner case
-        frame = DataFrame()
+        frame = empty_frame()
         ct1 = frame.count(1)
         assert isinstance(ct1, Series)
 
@@ -23,7 +23,7 @@ def test_count(self):
         expected = Series(0, index=df.columns)
         tm.assert_series_equal(result, expected)
 
-        df = DataFrame()
+        df = empty_frame()
         result = df.count()
         expected = Series(0, index=[])
         tm.assert_series_equal(result, expected)

pandas/tests/frame/methods/test_drop_duplicates.py

@@ -193,7 +193,7 @@ def test_drop_duplicates_tuple():
 @pytest.mark.parametrize(
     "df",
     [
-        DataFrame(),
+        empty_frame(),
         DataFrame(columns=[]),
         DataFrame(columns=["A", "B", "C"]),
         DataFrame(index=[]),

pandas/tests/frame/methods/test_filter.py

@@ -122,7 +122,7 @@ def test_filter_bytestring(self, name):
         tm.assert_frame_equal(df.filter(regex=name), expected)
 
     def test_filter_corner(self):
-        empty = DataFrame()
+        empty = empty_frame()
 
         result = empty.filter([])
         tm.assert_frame_equal(result, empty)

pandas/tests/frame/methods/test_head_tail.py

@@ -25,6 +25,6 @@ def test_head_tail(float_frame):
     tm.assert_frame_equal(df.head(-1), df.iloc[:-1])
     tm.assert_frame_equal(df.tail(-1), df.iloc[1:])
     # test empty dataframe
-    empty_df = DataFrame()
+    empty_df = empty_frame()
     tm.assert_frame_equal(empty_df.tail(), empty_df)
     tm.assert_frame_equal(empty_df.head(), empty_df)

pandas/tests/frame/methods/test_isin.py

@@ -176,7 +176,7 @@ def test_isin_empty_datetimelike(self):
         df1_ts = DataFrame({"date": pd.to_datetime(["2014-01-01", "2014-01-02"])})
         df1_td = DataFrame({"date": [pd.Timedelta(1, "s"), pd.Timedelta(2, "s")]})
         df2 = DataFrame({"date": []})
-        df3 = DataFrame()
+        df3 = empty_frame()
 
         expected = DataFrame({"date": [False, False]})
 

pandas/tests/frame/methods/test_round.py

@@ -11,7 +11,7 @@ def test_round(self):
         # GH#2665
 
         # Test that rounding an empty DataFrame does nothing
-        df = DataFrame()
+        df = empty_frame()
         tm.assert_frame_equal(df, df.round())
 
         # Here's the test frame we'll be working with

pandas/tests/frame/test_analytics.py

@@ -754,7 +754,7 @@ def test_operators_timedelta64(self):
         assert df["off2"].dtype == "timedelta64[ns]"
 
     def test_sum_corner(self):
-        empty_frame = DataFrame()
+        empty_frame = empty_frame()
 
         axis0 = empty_frame.sum(0)
         axis1 = empty_frame.sum(1)

pandas/tests/frame/test_api.py

@@ -118,7 +118,7 @@ def test_tab_completion(self):
         assert isinstance(df.__getitem__("A"), pd.DataFrame)
 
     def test_not_hashable(self):
-        empty_frame = DataFrame()
+        empty_frame = empty_frame()
 
         df = DataFrame([1])
         msg = "'DataFrame' objects are mutable, thus they cannot be hashed"
@@ -162,7 +162,7 @@ def test_get_agg_axis(self, float_frame):
             float_frame._get_agg_axis(2)
 
     def test_nonzero(self, float_frame, float_string_frame):
-        empty_frame = DataFrame()
+        empty_frame = empty_frame()
         assert empty_frame.empty
 
         assert not float_frame.empty
@@ -423,7 +423,7 @@ def test_empty_nonzero(self):
         assert df.empty
         assert df.T.empty
         empty_frames = [
-            DataFrame(),
+            empty_frame(),
             DataFrame(index=[1]),
             DataFrame(columns=[1]),
             DataFrame({1: []}),

pandas/tests/frame/test_apply.py

@@ -74,7 +74,7 @@ def test_apply_mixed_datetimelike(self):
 
     def test_apply_empty(self, float_frame):
         # empty
-        empty_frame = DataFrame()
+        empty_frame = empty_frame()
 
         applied = empty_frame.apply(np.sqrt)
         assert applied.empty
@@ -99,7 +99,7 @@ def test_apply_empty(self, float_frame):
 
     def test_apply_with_reduce_empty(self):
         # reduce with an empty DataFrame
-        empty_frame = DataFrame()
+        empty_frame = empty_frame()
 
         x = []
         result = empty_frame.apply(x.append, axis=1, result_type="expand")
@@ -760,7 +760,7 @@ def test_with_dictlike_columns(self):
         tm.assert_series_equal(result, expected)
 
         # GH 18775
-        df = DataFrame()
+        df = empty_frame()
         df["author"] = ["X", "Y", "Z"]
         df["publisher"] = ["BBC", "NBC", "N24"]
         df["date"] = pd.to_datetime(
@@ -1323,7 +1323,7 @@ def func(group_col):
         "df, func, expected",
         chain(
             tm.get_cython_table_params(
-                DataFrame(),
+                empty_frame(),
                 [
                     ("sum", Series(dtype="float64")),
                     ("max", Series(dtype="float64")),
@@ -1365,7 +1365,7 @@ def test_agg_cython_table(self, df, func, expected, axis):
         "df, func, expected",
         chain(
             tm.get_cython_table_params(
-                DataFrame(), [("cumprod", DataFrame()), ("cumsum", DataFrame())]
+                empty_frame(), [("cumprod", empty_frame()), ("cumsum", empty_frame())]
             ),
             tm.get_cython_table_params(
                 DataFrame([[np.nan, 1], [1, 2]]),

pandas/tests/frame/test_arithmetic.py

@@ -990,13 +990,13 @@ def test_combineFrame(self, float_frame, mixed_float_frame, mixed_int_frame):
         # corner cases
 
         # empty
-        plus_empty = float_frame + DataFrame()
+        plus_empty = float_frame + empty_frame()
         assert np.isnan(plus_empty.values).all()
 
-        empty_plus = DataFrame() + float_frame
+        empty_plus = empty_frame() + float_frame
         assert np.isnan(empty_plus.values).all()
 
-        empty_empty = DataFrame() + DataFrame()
+        empty_empty = empty_frame() + empty_frame()
         assert empty_empty.empty
 
         # out of order
@@ -1116,7 +1116,7 @@ def test_combineFunc(self, float_frame, mixed_float_frame):
             tm.assert_numpy_array_equal(s.values, mixed_float_frame[c].values * 2)
         _check_mixed_float(result, dtype=dict(C=None))
 
-        result = DataFrame() * 2
+        result = empty_frame() * 2
         assert result.index.equals(DataFrame().index)
         assert len(result.columns) == 0
 

pandas/tests/frame/test_block_internals.py

@@ -345,7 +345,7 @@ def test_copy(self, float_frame, float_string_frame):
         assert copy._data is not float_string_frame._data
 
     def test_pickle(self, float_string_frame, timezone_frame):
-        empty_frame = DataFrame()
+        empty_frame = empty_frame()
 
         unpickled = tm.round_trip_pickle(float_string_frame)
         tm.assert_frame_equal(float_string_frame, unpickled)

pandas/tests/frame/test_constructors.py

@@ -62,7 +62,7 @@ def test_series_with_name_not_matching_column(self):
     @pytest.mark.parametrize(
         "constructor",
         [
-            lambda: DataFrame(),
+            lambda: empty_frame(),
             lambda: DataFrame(None),
             lambda: DataFrame({}),
             lambda: DataFrame(()),
@@ -78,7 +78,7 @@ def test_series_with_name_not_matching_column(self):
         ],
     )
     def test_empty_constructor(self, constructor):
-        expected = DataFrame()
+        expected = empty_frame()
         result = constructor()
         assert len(result.index) == 0
         assert len(result.columns) == 0
@@ -1774,7 +1774,7 @@ def test_constructor_with_datetimes(self):
         i = date_range("1/1/2011", periods=5, freq="10s", tz="US/Eastern")
 
         expected = DataFrame({"a": i.to_series().reset_index(drop=True)})
-        df = DataFrame()
+        df = empty_frame()
         df["a"] = i
         tm.assert_frame_equal(df, expected)
 

pandas/tests/frame/test_missing.py

@@ -167,7 +167,7 @@ def test_dropna_multiple_axes(self):
 
     def test_dropna_tz_aware_datetime(self):
         # GH13407
-        df = DataFrame()
+        df = empty_frame()
         dt1 = datetime.datetime(2015, 1, 1, tzinfo=dateutil.tz.tzutc())
         dt2 = datetime.datetime(2015, 2, 2, tzinfo=dateutil.tz.tzutc())
         df["Time"] = [dt1]

pandas/tests/frame/test_repr_info.py

@@ -63,7 +63,7 @@ def test_repr(self, float_frame):
         repr(no_index)
 
         # no columns or index
-        DataFrame().info(buf=buf)
+        empty_frame().info(buf=buf)
 
         df = DataFrame(["a\n\r\tb"], columns=["a\n\r\td"], index=["a\n\r\tf"])
         assert "\t" not in repr(df)

pandas/tests/frame/test_reshape.py

@@ -53,7 +53,7 @@ def test_pivot_duplicates(self):
     def test_pivot_empty(self):
         df = DataFrame(columns=["a", "b", "c"])
         result = df.pivot("a", "b", "c")
-        expected = DataFrame()
+        expected = empty_frame()
         tm.assert_frame_equal(result, expected, check_names=False)
 
     def test_pivot_integer_bug(self):

pandas/tests/groupby/aggregate/test_aggregate.py

@@ -223,7 +223,7 @@ def test_aggregate_item_by_item(df):
     def aggfun(ser):
         return ser.size
 
-    result = DataFrame().groupby(df.A).agg(aggfun)
+    result = empty_frame().groupby(df.A).agg(aggfun)
     assert isinstance(result, DataFrame)
     assert len(result) == 0
 

pandas/tests/groupby/test_apply.py

@@ -658,7 +658,7 @@ def test_func(x):
         pass
 
     result = test_df.groupby("groups").apply(test_func)
-    expected = DataFrame()
+    expected = empty_frame()
     tm.assert_frame_equal(result, expected)
 
 

pandas/tests/groupby/test_counting.py

@@ -19,7 +19,7 @@ def test_cumcount(self):
         tm.assert_series_equal(expected, sg.cumcount())
 
     def test_cumcount_empty(self):
-        ge = DataFrame().groupby(level=0)
+        ge = empty_frame().groupby(level=0)
         se = Series(dtype=object).groupby(level=0)
 
         # edge case, as this is usually considered float
@@ -94,7 +94,7 @@ def test_ngroup_one_group(self):
         tm.assert_series_equal(expected, sg.ngroup())
 
     def test_ngroup_empty(self):
-        ge = DataFrame().groupby(level=0)
+        ge = empty_frame().groupby(level=0)
         se = Series(dtype=object).groupby(level=0)
 
         # edge case, as this is usually considered float

pandas/tests/groupby/test_groupby.py

@@ -310,7 +310,7 @@ def f1(x):
     def f2(x):
         y = x[(x.b % 2) == 1] ** 2
         if y.empty:
-            return DataFrame()
+            return empty_frame()
         else:
             y = y.set_index(["b", "c"])
             return y

pandas/tests/indexes/datetimes/test_datetime.py

@@ -236,7 +236,7 @@ def test_groupby_function_tuple_1677(self):
     def test_append_numpy_bug_1681(self):
         # another datetime64 bug
         dr = date_range("2011/1/1", "2012/1/1", freq="W-FRI")
-        a = DataFrame()
+        a = empty_frame()
         c = DataFrame({"A": "foo", "B": dr}, index=dr)
 
         result = a.append(c)

pandas/tests/indexes/timedeltas/test_timedelta.py

@@ -171,7 +171,7 @@ def test_pass_TimedeltaIndex_to_index(self):
     def test_append_numpy_bug_1681(self):
 
         td = timedelta_range("1 days", "10 days", freq="2D")
-        a = DataFrame()
+        a = empty_frame()
         c = DataFrame({"A": "foo", "B": td}, index=td)
         str(c)