""" test label based indexing with loc """ from io import StringIO import re from warnings import catch_warnings, filterwarnings import numpy as np import pytest import pandas as pd from pandas import DataFrame, Series, Timestamp, date_range from pandas.api.types import is_scalar from pandas.tests.indexing.common import Base from pandas.util import testing as tm class TestLoc(Base): def test_loc_getitem_dups(self): # GH 5678 # repeated getitems on a dup index returning a ndarray df = DataFrame( np.random.random_sample((20, 5)), index=["ABCDE"[x % 5] for x in range(20)] ) expected = df.loc["A", 0] result = df.loc[:, 0].loc["A"] tm.assert_series_equal(result, expected) def test_loc_getitem_dups2(self): # GH4726 # dup indexing with iloc/loc df = DataFrame( [[1, 2, "foo", "bar", Timestamp("20130101")]], columns=["a", "a", "a", "a", "a"], index=[1], ) expected = Series( [1, 2, "foo", "bar", Timestamp("20130101")], index=["a", "a", "a", "a", "a"], name=1, ) result = df.iloc[0] tm.assert_series_equal(result, expected) result = df.loc[1] tm.assert_series_equal(result, expected) def test_loc_setitem_dups(self): # GH 6541 df_orig = DataFrame( { "me": list("rttti"), "foo": list("aaade"), "bar": np.arange(5, dtype="float64") * 1.34 + 2, "bar2": np.arange(5, dtype="float64") * -0.34 + 2, } ).set_index("me") indexer = tuple(["r", ["bar", "bar2"]]) df = df_orig.copy() df.loc[indexer] *= 2.0 tm.assert_series_equal(df.loc[indexer], 2.0 * df_orig.loc[indexer]) indexer = tuple(["r", "bar"]) df = df_orig.copy() df.loc[indexer] *= 2.0 assert df.loc[indexer] == 2.0 * df_orig.loc[indexer] indexer = tuple(["t", ["bar", "bar2"]]) df = df_orig.copy() df.loc[indexer] *= 2.0 tm.assert_frame_equal(df.loc[indexer], 2.0 * df_orig.loc[indexer]) def test_loc_setitem_slice(self): # GH10503 # assigning the same type should not change the type df1 = DataFrame({"a": [0, 1, 1], "b": Series([100, 200, 300], dtype="uint32")}) ix = df1["a"] == 1 newb1 = df1.loc[ix, "b"] + 1 df1.loc[ix, "b"] = newb1 expected = DataFrame( {"a": [0, 1, 1], "b": Series([100, 201, 301], dtype="uint32")} ) tm.assert_frame_equal(df1, expected) # assigning a new type should get the inferred type df2 = DataFrame({"a": [0, 1, 1], "b": [100, 200, 300]}, dtype="uint64") ix = df1["a"] == 1 newb2 = df2.loc[ix, "b"] df1.loc[ix, "b"] = newb2 expected = DataFrame({"a": [0, 1, 1], "b": [100, 200, 300]}, dtype="uint64") tm.assert_frame_equal(df2, expected) def test_loc_getitem_int(self): # int label self.check_result( "int label", "loc", 2, "ix", 2, typs=["ints", "uints"], axes=0 ) self.check_result( "int label", "loc", 3, "ix", 3, typs=["ints", "uints"], axes=1 ) self.check_result( "int label", "loc", 2, "ix", 2, typs=["label"], fails=KeyError ) def test_loc_getitem_label(self): # label self.check_result("label", "loc", "c", "ix", "c", typs=["labels"], axes=0) self.check_result("label", "loc", "null", "ix", "null", typs=["mixed"], axes=0) self.check_result("label", "loc", 8, "ix", 8, typs=["mixed"], axes=0) self.check_result( "label", "loc", Timestamp("20130102"), "ix", 1, typs=["ts"], axes=0 ) self.check_result( "label", "loc", "c", "ix", "c", typs=["empty"], fails=KeyError ) def test_loc_getitem_label_out_of_range(self): # out of range label self.check_result( "label range", "loc", "f", "ix", "f", typs=["ints", "uints", "labels", "mixed", "ts"], fails=KeyError, ) self.check_result( "label range", "loc", "f", "ix", "f", typs=["floats"], fails=KeyError ) self.check_result( "label range", "loc", 20, "ix", 20, typs=["ints", "uints", "mixed"], fails=KeyError, ) self.check_result( "label range", "loc", 20, "ix", 20, typs=["labels"], fails=TypeError ) self.check_result( "label range", "loc", 20, "ix", 20, typs=["ts"], axes=0, fails=TypeError ) self.check_result( "label range", "loc", 20, "ix", 20, typs=["floats"], axes=0, fails=KeyError ) def test_loc_getitem_label_list(self): # list of labels self.check_result( "list lbl", "loc", [0, 2, 4], "ix", [0, 2, 4], typs=["ints", "uints"], axes=0, ) self.check_result( "list lbl", "loc", [3, 6, 9], "ix", [3, 6, 9], typs=["ints", "uints"], axes=1, ) self.check_result( "list lbl", "loc", ["a", "b", "d"], "ix", ["a", "b", "d"], typs=["labels"], axes=0, ) self.check_result( "list lbl", "loc", ["A", "B", "C"], "ix", ["A", "B", "C"], typs=["labels"], axes=1, ) self.check_result( "list lbl", "loc", [2, 8, "null"], "ix", [2, 8, "null"], typs=["mixed"], axes=0, ) self.check_result( "list lbl", "loc", [Timestamp("20130102"), Timestamp("20130103")], "ix", [Timestamp("20130102"), Timestamp("20130103")], typs=["ts"], axes=0, ) def test_loc_getitem_label_list_with_missing(self): self.check_result( "list lbl", "loc", [0, 1, 2], "indexer", [0, 1, 2], typs=["empty"], fails=KeyError, ) with tm.assert_produces_warning(FutureWarning, check_stacklevel=False): self.check_result( "list lbl", "loc", [0, 2, 10], "ix", [0, 2, 10], typs=["ints", "uints", "floats"], axes=0, fails=KeyError, ) with tm.assert_produces_warning(FutureWarning, check_stacklevel=False): self.check_result( "list lbl", "loc", [3, 6, 7], "ix", [3, 6, 7], typs=["ints", "uints", "floats"], axes=1, fails=KeyError, ) # GH 17758 - MultiIndex and missing keys with tm.assert_produces_warning(FutureWarning, check_stacklevel=False): self.check_result( "list lbl", "loc", [(1, 3), (1, 4), (2, 5)], "ix", [(1, 3), (1, 4), (2, 5)], typs=["multi"], axes=0, ) def test_getitem_label_list_with_missing(self): s = Series(range(3), index=["a", "b", "c"]) # consistency with tm.assert_produces_warning(FutureWarning, check_stacklevel=False): s[["a", "d"]] s = Series(range(3)) with tm.assert_produces_warning(FutureWarning, check_stacklevel=False): s[[0, 3]] def test_loc_getitem_label_list_fails(self): # fails self.check_result( "list lbl", "loc", [20, 30, 40], "ix", [20, 30, 40], typs=["ints", "uints"], axes=1, fails=KeyError, ) def test_loc_getitem_label_array_like(self): # array like self.check_result( "array like", "loc", Series(index=[0, 2, 4]).index, "ix", [0, 2, 4], typs=["ints", "uints"], axes=0, ) self.check_result( "array like", "loc", Series(index=[3, 6, 9]).index, "ix", [3, 6, 9], typs=["ints", "uints"], axes=1, ) def test_loc_getitem_bool(self): # boolean indexers b = [True, False, True, False] self.check_result( "bool", "loc", b, "ix", b, typs=["ints", "uints", "labels", "mixed", "ts", "floats"], ) self.check_result("bool", "loc", b, "ix", b, typs=["empty"], fails=IndexError) @pytest.mark.parametrize("index", [[True, False], [True, False, True, False]]) def test_loc_getitem_bool_diff_len(self, index): # GH26658 s = Series([1, 2, 3]) with pytest.raises( IndexError, match=("Item wrong length {} instead of {}.".format(len(index), len(s))), ): _ = s.loc[index] def test_loc_getitem_int_slice(self): # ok self.check_result( "int slice2", "loc", slice(2, 4), "ix", [2, 4], typs=["ints", "uints"], axes=0, ) self.check_result( "int slice2", "loc", slice(3, 6), "ix", [3, 6], typs=["ints", "uints"], axes=1, ) def test_loc_to_fail(self): # GH3449 df = DataFrame( np.random.random((3, 3)), index=["a", "b", "c"], columns=["e", "f", "g"] ) # raise a KeyError? msg = ( r"\"None of \[Int64Index\(\[1, 2\], dtype='int64'\)\] are" r" in the \[index\]\"" ) with pytest.raises(KeyError, match=msg): df.loc[[1, 2], [1, 2]] # GH 7496 # loc should not fallback s = Series() s.loc[1] = 1 s.loc["a"] = 2 with pytest.raises(KeyError, match=r"^-1$"): s.loc[-1] msg = ( r"\"None of \[Int64Index\(\[-1, -2\], dtype='int64'\)\] are" r" in the \[index\]\"" ) with pytest.raises(KeyError, match=msg): s.loc[[-1, -2]] msg = ( r"\"None of \[Index\(\['4'\], dtype='object'\)\] are" r" in the \[index\]\"" ) with pytest.raises(KeyError, match=msg): s.loc[["4"]] s.loc[-1] = 3 with tm.assert_produces_warning(FutureWarning, check_stacklevel=False): result = s.loc[[-1, -2]] expected = Series([3, np.nan], index=[-1, -2]) tm.assert_series_equal(result, expected) s["a"] = 2 msg = ( r"\"None of \[Int64Index\(\[-2\], dtype='int64'\)\] are" r" in the \[index\]\"" ) with pytest.raises(KeyError, match=msg): s.loc[[-2]] del s["a"] with pytest.raises(KeyError, match=msg): s.loc[[-2]] = 0 # inconsistency between .loc[values] and .loc[values,:] # GH 7999 df = DataFrame([["a"], ["b"]], index=[1, 2], columns=["value"]) msg = ( r"\"None of \[Int64Index\(\[3\], dtype='int64'\)\] are" r" in the \[index\]\"" ) with pytest.raises(KeyError, match=msg): df.loc[[3], :] with pytest.raises(KeyError, match=msg): df.loc[[3]] def test_loc_getitem_list_with_fail(self): # 15747 # should KeyError if *any* missing labels s = Series([1, 2, 3]) s.loc[[2]] with pytest.raises( KeyError, match=re.escape( "\"None of [Int64Index([3], dtype='int64')] are in the [index]\"" ), ): s.loc[[3]] # a non-match and a match with tm.assert_produces_warning(FutureWarning): expected = s.loc[[2, 3]] result = s.reindex([2, 3]) tm.assert_series_equal(result, expected) def test_loc_getitem_label_slice(self): # label slices (with ints) self.check_result( "lab slice", "loc", slice(1, 3), "ix", slice(1, 3), typs=["labels", "mixed", "empty", "ts", "floats"], fails=TypeError, ) # real label slices self.check_result( "lab slice", "loc", slice("a", "c"), "ix", slice("a", "c"), typs=["labels"], axes=0, ) self.check_result( "lab slice", "loc", slice("A", "C"), "ix", slice("A", "C"), typs=["labels"], axes=1, ) self.check_result( "ts slice", "loc", slice("20130102", "20130104"), "ix", slice("20130102", "20130104"), typs=["ts"], axes=0, ) self.check_result( "ts slice", "loc", slice("20130102", "20130104"), "ix", slice("20130102", "20130104"), typs=["ts"], axes=1, fails=TypeError, ) # GH 14316 self.check_result( "ts slice rev", "loc", slice("20130104", "20130102"), "indexer", [0, 1, 2], typs=["ts_rev"], axes=0, ) self.check_result( "mixed slice", "loc", slice(2, 8), "ix", slice(2, 8), typs=["mixed"], axes=0, fails=TypeError, ) self.check_result( "mixed slice", "loc", slice(2, 8), "ix", slice(2, 8), typs=["mixed"], axes=1, fails=KeyError, ) self.check_result( "mixed slice", "loc", slice(2, 4, 2), "ix", slice(2, 4, 2), typs=["mixed"], axes=0, fails=TypeError, ) def test_loc_index(self): # gh-17131 # a boolean index should index like a boolean numpy array df = DataFrame( np.random.random(size=(5, 10)), index=["alpha_0", "alpha_1", "alpha_2", "beta_0", "beta_1"], ) mask = df.index.map(lambda x: "alpha" in x) expected = df.loc[np.array(mask)] result = df.loc[mask] tm.assert_frame_equal(result, expected) result = df.loc[mask.values] tm.assert_frame_equal(result, expected) def test_loc_general(self): df = DataFrame( np.random.rand(4, 4), columns=["A", "B", "C", "D"], index=["A", "B", "C", "D"], ) # want this to work result = df.loc[:, "A":"B"].iloc[0:2, :] assert (result.columns == ["A", "B"]).all() assert (result.index == ["A", "B"]).all() # mixed type result = DataFrame({"a": [Timestamp("20130101")], "b": [1]}).iloc[0] expected = Series([Timestamp("20130101"), 1], index=["a", "b"], name=0) tm.assert_series_equal(result, expected) assert result.dtype == object def test_loc_setitem_consistency(self): # GH 6149 # coerce similarly for setitem and loc when rows have a null-slice expected = DataFrame( { "date": Series(0, index=range(5), dtype=np.int64), "val": Series(range(5), dtype=np.int64), } ) df = DataFrame( { "date": date_range("2000-01-01", "2000-01-5"), "val": Series(range(5), dtype=np.int64), } ) df.loc[:, "date"] = 0 tm.assert_frame_equal(df, expected) df = DataFrame( { "date": date_range("2000-01-01", "2000-01-5"), "val": Series(range(5), dtype=np.int64), } ) df.loc[:, "date"] = np.array(0, dtype=np.int64) tm.assert_frame_equal(df, expected) df = DataFrame( { "date": date_range("2000-01-01", "2000-01-5"), "val": Series(range(5), dtype=np.int64), } ) df.loc[:, "date"] = np.array([0, 0, 0, 0, 0], dtype=np.int64) tm.assert_frame_equal(df, expected) expected = DataFrame( { "date": Series("foo", index=range(5)), "val": Series(range(5), dtype=np.int64), } ) df = DataFrame( { "date": date_range("2000-01-01", "2000-01-5"), "val": Series(range(5), dtype=np.int64), } ) df.loc[:, "date"] = "foo" tm.assert_frame_equal(df, expected) expected = DataFrame( { "date": Series(1.0, index=range(5)), "val": Series(range(5), dtype=np.int64), } ) df = DataFrame( { "date": date_range("2000-01-01", "2000-01-5"), "val": Series(range(5), dtype=np.int64), } ) df.loc[:, "date"] = 1.0 tm.assert_frame_equal(df, expected) # GH 15494 # setting on frame with single row df = DataFrame({"date": Series([Timestamp("20180101")])}) df.loc[:, "date"] = "string" expected = DataFrame({"date": Series(["string"])}) tm.assert_frame_equal(df, expected) def test_loc_setitem_consistency_empty(self): # empty (essentially noops) expected = DataFrame(columns=["x", "y"]) expected["x"] = expected["x"].astype(np.int64) df = DataFrame(columns=["x", "y"]) df.loc[:, "x"] = 1 tm.assert_frame_equal(df, expected) df = DataFrame(columns=["x", "y"]) df["x"] = 1 tm.assert_frame_equal(df, expected) def test_loc_setitem_consistency_slice_column_len(self): # .loc[:,column] setting with slice == len of the column # GH10408 data = """Level_0,,,Respondent,Respondent,Respondent,OtherCat,OtherCat Level_1,,,Something,StartDate,EndDate,Yes/No,SomethingElse Region,Site,RespondentID,,,,, Region_1,Site_1,3987227376,A,5/25/2015 10:59,5/25/2015 11:22,Yes, Region_1,Site_1,3980680971,A,5/21/2015 9:40,5/21/2015 9:52,Yes,Yes Region_1,Site_2,3977723249,A,5/20/2015 8:27,5/20/2015 8:41,Yes, Region_1,Site_2,3977723089,A,5/20/2015 8:33,5/20/2015 9:09,Yes,No""" df = pd.read_csv(StringIO(data), header=[0, 1], index_col=[0, 1, 2]) df.loc[:, ("Respondent", "StartDate")] = pd.to_datetime( df.loc[:, ("Respondent", "StartDate")] ) df.loc[:, ("Respondent", "EndDate")] = pd.to_datetime( df.loc[:, ("Respondent", "EndDate")] ) df.loc[:, ("Respondent", "Duration")] = ( df.loc[:, ("Respondent", "EndDate")] - df.loc[:, ("Respondent", "StartDate")] ) df.loc[:, ("Respondent", "Duration")] = df.loc[ :, ("Respondent", "Duration") ].astype("timedelta64[s]") expected = Series( [1380, 720, 840, 2160.0], index=df.index, name=("Respondent", "Duration") ) tm.assert_series_equal(df[("Respondent", "Duration")], expected) def test_loc_setitem_frame(self): df = self.frame_labels result = df.iloc[0, 0] df.loc["a", "A"] = 1 result = df.loc["a", "A"] assert result == 1 result = df.iloc[0, 0] assert result == 1 df.loc[:, "B":"D"] = 0 expected = df.loc[:, "B":"D"] result = df.iloc[:, 1:] tm.assert_frame_equal(result, expected) # GH 6254 # setting issue df = DataFrame(index=[3, 5, 4], columns=["A"]) df.loc[[4, 3, 5], "A"] = np.array([1, 2, 3], dtype="int64") expected = DataFrame(dict(A=Series([1, 2, 3], index=[4, 3, 5]))).reindex( index=[3, 5, 4] ) tm.assert_frame_equal(df, expected) # GH 6252 # setting with an empty frame keys1 = ["@" + str(i) for i in range(5)] val1 = np.arange(5, dtype="int64") keys2 = ["@" + str(i) for i in range(4)] val2 = np.arange(4, dtype="int64") index = list(set(keys1).union(keys2)) df = DataFrame(index=index) df["A"] = np.nan df.loc[keys1, "A"] = val1 df["B"] = np.nan df.loc[keys2, "B"] = val2 expected = DataFrame( dict(A=Series(val1, index=keys1), B=Series(val2, index=keys2)) ).reindex(index=index) tm.assert_frame_equal(df, expected) # GH 8669 # invalid coercion of nan -> int df = DataFrame({"A": [1, 2, 3], "B": np.nan}) df.loc[df.B > df.A, "B"] = df.A expected = DataFrame({"A": [1, 2, 3], "B": np.nan}) tm.assert_frame_equal(df, expected) # GH 6546 # setting with mixed labels df = DataFrame({1: [1, 2], 2: [3, 4], "a": ["a", "b"]}) result = df.loc[0, [1, 2]] expected = Series([1, 3], index=[1, 2], dtype=object, name=0) tm.assert_series_equal(result, expected) expected = DataFrame({1: [5, 2], 2: [6, 4], "a": ["a", "b"]}) df.loc[0, [1, 2]] = [5, 6] tm.assert_frame_equal(df, expected) def test_loc_setitem_frame_multiples(self): # multiple setting df = DataFrame( {"A": ["foo", "bar", "baz"], "B": Series(range(3), dtype=np.int64)} ) rhs = df.loc[1:2] rhs.index = df.index[0:2] df.loc[0:1] = rhs expected = DataFrame( {"A": ["bar", "baz", "baz"], "B": Series([1, 2, 2], dtype=np.int64)} ) tm.assert_frame_equal(df, expected) # multiple setting with frame on rhs (with M8) df = DataFrame( { "date": date_range("2000-01-01", "2000-01-5"), "val": Series(range(5), dtype=np.int64), } ) expected = DataFrame( { "date": [ Timestamp("20000101"), Timestamp("20000102"), Timestamp("20000101"), Timestamp("20000102"), Timestamp("20000103"), ], "val": Series([0, 1, 0, 1, 2], dtype=np.int64), } ) rhs = df.loc[0:2] rhs.index = df.index[2:5] df.loc[2:4] = rhs tm.assert_frame_equal(df, expected) @pytest.mark.parametrize( "indexer", [["A"], slice(None, "A", None), np.array(["A"])] ) @pytest.mark.parametrize("value", [["Z"], np.array(["Z"])]) def test_loc_setitem_with_scalar_index(self, indexer, value): # GH #19474 # assigning like "df.loc[0, ['A']] = ['Z']" should be evaluated # elementwisely, not using "setter('A', ['Z'])". df = pd.DataFrame([[1, 2], [3, 4]], columns=["A", "B"]) df.loc[0, indexer] = value result = df.loc[0, "A"] assert is_scalar(result) and result == "Z" def test_loc_coercion(self): # 12411 df = DataFrame({"date": [Timestamp("20130101").tz_localize("UTC"), pd.NaT]}) expected = df.dtypes result = df.iloc[[0]] tm.assert_series_equal(result.dtypes, expected) result = df.iloc[[1]] tm.assert_series_equal(result.dtypes, expected) # 12045 import datetime df = DataFrame( {"date": [datetime.datetime(2012, 1, 1), datetime.datetime(1012, 1, 2)]} ) expected = df.dtypes result = df.iloc[[0]] tm.assert_series_equal(result.dtypes, expected) result = df.iloc[[1]] tm.assert_series_equal(result.dtypes, expected) # 11594 df = DataFrame({"text": ["some words"] + [None] * 9}) expected = df.dtypes result = df.iloc[0:2] tm.assert_series_equal(result.dtypes, expected) result = df.iloc[3:] tm.assert_series_equal(result.dtypes, expected) def test_setitem_new_key_tz(self): # GH#12862 should not raise on assigning the second value vals = [ pd.to_datetime(42).tz_localize("UTC"), pd.to_datetime(666).tz_localize("UTC"), ] expected = pd.Series(vals, index=["foo", "bar"]) ser = pd.Series() ser["foo"] = vals[0] ser["bar"] = vals[1] tm.assert_series_equal(ser, expected) ser = pd.Series() ser.loc["foo"] = vals[0] ser.loc["bar"] = vals[1] tm.assert_series_equal(ser, expected) def test_loc_non_unique(self): # GH3659 # non-unique indexer with loc slice # https://groups.google.com/forum/?fromgroups#!topic/pydata/zTm2No0crYs # these are going to raise because the we are non monotonic df = DataFrame( {"A": [1, 2, 3, 4, 5, 6], "B": [3, 4, 5, 6, 7, 8]}, index=[0, 1, 0, 1, 2, 3] ) msg = "'Cannot get left slice bound for non-unique label: 1'" with pytest.raises(KeyError, match=msg): df.loc[1:] msg = "'Cannot get left slice bound for non-unique label: 0'" with pytest.raises(KeyError, match=msg): df.loc[0:] msg = "'Cannot get left slice bound for non-unique label: 1'" with pytest.raises(KeyError, match=msg): df.loc[1:2] # monotonic are ok df = DataFrame( {"A": [1, 2, 3, 4, 5, 6], "B": [3, 4, 5, 6, 7, 8]}, index=[0, 1, 0, 1, 2, 3] ).sort_index(axis=0) result = df.loc[1:] expected = DataFrame({"A": [2, 4, 5, 6], "B": [4, 6, 7, 8]}, index=[1, 1, 2, 3]) tm.assert_frame_equal(result, expected) result = df.loc[0:] tm.assert_frame_equal(result, df) result = df.loc[1:2] expected = DataFrame({"A": [2, 4, 5], "B": [4, 6, 7]}, index=[1, 1, 2]) tm.assert_frame_equal(result, expected) def test_loc_non_unique_memory_error(self): # GH 4280 # non_unique index with a large selection triggers a memory error columns = list("ABCDEFG") def gen_test(l, l2): return pd.concat( [ DataFrame( np.random.randn(l, len(columns)), index=np.arange(l), columns=columns, ), DataFrame( np.ones((l2, len(columns))), index=[0] * l2, columns=columns ), ] ) def gen_expected(df, mask): len_mask = len(mask) return pd.concat( [ df.take([0]), DataFrame( np.ones((len_mask, len(columns))), index=[0] * len_mask, columns=columns, ), df.take(mask[1:]), ] ) df = gen_test(900, 100) assert df.index.is_unique is False mask = np.arange(100) result = df.loc[mask] expected = gen_expected(df, mask) tm.assert_frame_equal(result, expected) df = gen_test(900000, 100000) assert df.index.is_unique is False mask = np.arange(100000) result = df.loc[mask] expected = gen_expected(df, mask) tm.assert_frame_equal(result, expected) def test_loc_name(self): # GH 3880 df = DataFrame([[1, 1], [1, 1]]) df.index.name = "index_name" result = df.iloc[[0, 1]].index.name assert result == "index_name" with catch_warnings(record=True): filterwarnings("ignore", "\\n.ix", FutureWarning) result = df.ix[[0, 1]].index.name assert result == "index_name" result = df.loc[[0, 1]].index.name assert result == "index_name" def test_loc_empty_list_indexer_is_ok(self): from pandas.util.testing import makeCustomDataframe as mkdf df = mkdf(5, 2) # vertical empty tm.assert_frame_equal( df.loc[:, []], df.iloc[:, :0], check_index_type=True, check_column_type=True ) # horizontal empty tm.assert_frame_equal( df.loc[[], :], df.iloc[:0, :], check_index_type=True, check_column_type=True ) # horizontal empty tm.assert_frame_equal( df.loc[[]], df.iloc[:0, :], check_index_type=True, check_column_type=True ) def test_identity_slice_returns_new_object(self): # GH13873 original_df = DataFrame({"a": [1, 2, 3]}) sliced_df = original_df.loc[:] assert sliced_df is not original_df assert original_df[:] is not original_df # should be a shallow copy original_df["a"] = [4, 4, 4] assert (sliced_df["a"] == 4).all() # These should not return copies assert original_df is original_df.loc[:, :] df = DataFrame(np.random.randn(10, 4)) assert df[0] is df.loc[:, 0] # Same tests for Series original_series = Series([1, 2, 3, 4, 5, 6]) sliced_series = original_series.loc[:] assert sliced_series is not original_series assert original_series[:] is not original_series original_series[:3] = [7, 8, 9] assert all(sliced_series[:3] == [7, 8, 9]) def test_loc_uint64(self): # GH20722 # Test whether loc accept uint64 max value as index. s = pd.Series( [1, 2], index=[np.iinfo("uint64").max - 1, np.iinfo("uint64").max] ) result = s.loc[np.iinfo("uint64").max - 1] expected = s.iloc[0] assert result == expected result = s.loc[[np.iinfo("uint64").max - 1]] expected = s.iloc[[0]] tm.assert_series_equal(result, expected) result = s.loc[[np.iinfo("uint64").max - 1, np.iinfo("uint64").max]] tm.assert_series_equal(result, s) def test_loc_setitem_empty_append(self): # GH6173, various appends to an empty dataframe data = [1, 2, 3] expected = DataFrame({"x": data, "y": [None] * len(data)}) # appends to fit length of data df = DataFrame(columns=["x", "y"]) df.loc[:, "x"] = data tm.assert_frame_equal(df, expected) # only appends one value expected = DataFrame({"x": [1.0], "y": [np.nan]}) df = DataFrame(columns=["x", "y"], dtype=np.float) df.loc[0, "x"] = expected.loc[0, "x"] tm.assert_frame_equal(df, expected) def test_loc_setitem_empty_append_raises(self): # GH6173, various appends to an empty dataframe data = [1, 2] df = DataFrame(columns=["x", "y"]) msg = ( r"None of \[Int64Index\(\[0, 1\], dtype='int64'\)\] " r"are in the \[index\]" ) with pytest.raises(KeyError, match=msg): df.loc[[0, 1], "x"] = data msg = "cannot copy sequence with size 2 to array axis with dimension 0" with pytest.raises(ValueError, match=msg): df.loc[0:2, "x"] = data def test_indexing_zerodim_np_array(self): # GH24924 df = DataFrame([[1, 2], [3, 4]]) result = df.loc[np.array(0)] s = pd.Series([1, 2], name=0) tm.assert_series_equal(result, s) def test_series_indexing_zerodim_np_array(self): # GH24924 s = Series([1, 2]) result = s.loc[np.array(0)] assert result == 1 def test_series_loc_getitem_label_list_missing_values(): # gh-11428 key = np.array( ["2001-01-04", "2001-01-02", "2001-01-04", "2001-01-14"], dtype="datetime64" ) s = Series([2, 5, 8, 11], date_range("2001-01-01", freq="D", periods=4)) expected = Series([11.0, 5.0, 11.0, np.nan], index=key) with tm.assert_produces_warning(FutureWarning, check_stacklevel=False): result = s.loc[key] tm.assert_series_equal(result, expected)