test_iloc.py 25.0 KB
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755
""" test positional based indexing with iloc """

from datetime import datetime
from warnings import catch_warnings, simplefilter

import numpy as np
import pytest

import pandas as pd
from pandas import DataFrame, Series, concat, date_range, isna
import pandas._testing as tm
from pandas.api.types import is_scalar
from pandas.core.indexing import IndexingError
from pandas.tests.indexing.common import Base


class TestiLoc(Base):
    def test_iloc_getitem_int(self):
        # integer
        self.check_result(
            "iloc",
            2,
            typs=["labels", "mixed", "ts", "floats", "empty"],
            fails=IndexError,
        )

    def test_iloc_getitem_neg_int(self):
        # neg integer
        self.check_result(
            "iloc",
            -1,
            typs=["labels", "mixed", "ts", "floats", "empty"],
            fails=IndexError,
        )

    def test_iloc_getitem_list_int(self):
        self.check_result(
            "iloc",
            [0, 1, 2],
            typs=["labels", "mixed", "ts", "floats", "empty"],
            fails=IndexError,
        )

        # array of ints (GH5006), make sure that a single indexer is returning
        # the correct type


class TestiLoc2:
    # TODO: better name, just separating out things that dont rely on base class

    def test_is_scalar_access(self):
        # GH#32085 index with duplicates doesnt matter for _is_scalar_access
        index = pd.Index([1, 2, 1])
        ser = pd.Series(range(3), index=index)

        assert ser.iloc._is_scalar_access((1,))

        df = ser.to_frame()
        assert df.iloc._is_scalar_access((1, 0,))

    def test_iloc_exceeds_bounds(self):

        # GH6296
        # iloc should allow indexers that exceed the bounds
        df = DataFrame(np.random.random_sample((20, 5)), columns=list("ABCDE"))

        # lists of positions should raise IndexError!
        msg = "positional indexers are out-of-bounds"
        with pytest.raises(IndexError, match=msg):
            df.iloc[:, [0, 1, 2, 3, 4, 5]]
        with pytest.raises(IndexError, match=msg):
            df.iloc[[1, 30]]
        with pytest.raises(IndexError, match=msg):
            df.iloc[[1, -30]]
        with pytest.raises(IndexError, match=msg):
            df.iloc[[100]]

        s = df["A"]
        with pytest.raises(IndexError, match=msg):
            s.iloc[[100]]
        with pytest.raises(IndexError, match=msg):
            s.iloc[[-100]]

        # still raise on a single indexer
        msg = "single positional indexer is out-of-bounds"
        with pytest.raises(IndexError, match=msg):
            df.iloc[30]
        with pytest.raises(IndexError, match=msg):
            df.iloc[-30]

        # GH10779
        # single positive/negative indexer exceeding Series bounds should raise
        # an IndexError
        with pytest.raises(IndexError, match=msg):
            s.iloc[30]
        with pytest.raises(IndexError, match=msg):
            s.iloc[-30]

        # slices are ok
        result = df.iloc[:, 4:10]  # 0 < start < len < stop
        expected = df.iloc[:, 4:]
        tm.assert_frame_equal(result, expected)

        result = df.iloc[:, -4:-10]  # stop < 0 < start < len
        expected = df.iloc[:, :0]
        tm.assert_frame_equal(result, expected)

        result = df.iloc[:, 10:4:-1]  # 0 < stop < len < start (down)
        expected = df.iloc[:, :4:-1]
        tm.assert_frame_equal(result, expected)

        result = df.iloc[:, 4:-10:-1]  # stop < 0 < start < len (down)
        expected = df.iloc[:, 4::-1]
        tm.assert_frame_equal(result, expected)

        result = df.iloc[:, -10:4]  # start < 0 < stop < len
        expected = df.iloc[:, :4]
        tm.assert_frame_equal(result, expected)

        result = df.iloc[:, 10:4]  # 0 < stop < len < start
        expected = df.iloc[:, :0]
        tm.assert_frame_equal(result, expected)

        result = df.iloc[:, -10:-11:-1]  # stop < start < 0 < len (down)
        expected = df.iloc[:, :0]
        tm.assert_frame_equal(result, expected)

        result = df.iloc[:, 10:11]  # 0 < len < start < stop
        expected = df.iloc[:, :0]
        tm.assert_frame_equal(result, expected)

        # slice bounds exceeding is ok
        result = s.iloc[18:30]
        expected = s.iloc[18:]
        tm.assert_series_equal(result, expected)

        result = s.iloc[30:]
        expected = s.iloc[:0]
        tm.assert_series_equal(result, expected)

        result = s.iloc[30::-1]
        expected = s.iloc[::-1]
        tm.assert_series_equal(result, expected)

        # doc example
        def check(result, expected):
            str(result)
            result.dtypes
            tm.assert_frame_equal(result, expected)

        dfl = DataFrame(np.random.randn(5, 2), columns=list("AB"))
        check(dfl.iloc[:, 2:3], DataFrame(index=dfl.index))
        check(dfl.iloc[:, 1:3], dfl.iloc[:, [1]])
        check(dfl.iloc[4:6], dfl.iloc[[4]])

        msg = "positional indexers are out-of-bounds"
        with pytest.raises(IndexError, match=msg):
            dfl.iloc[[4, 5, 6]]
        msg = "single positional indexer is out-of-bounds"
        with pytest.raises(IndexError, match=msg):
            dfl.iloc[:, 4]

    @pytest.mark.parametrize("index,columns", [(np.arange(20), list("ABCDE"))])
    @pytest.mark.parametrize(
        "index_vals,column_vals",
        [
            ([slice(None), ["A", "D"]]),
            (["1", "2"], slice(None)),
            ([datetime(2019, 1, 1)], slice(None)),
        ],
    )
    def test_iloc_non_integer_raises(self, index, columns, index_vals, column_vals):
        # GH 25753
        df = DataFrame(
            np.random.randn(len(index), len(columns)), index=index, columns=columns
        )
        msg = ".iloc requires numeric indexers, got"
        with pytest.raises(IndexError, match=msg):
            df.iloc[index_vals, column_vals]

    @pytest.mark.parametrize("dims", [1, 2])
    def test_iloc_getitem_invalid_scalar(self, dims):
        # GH 21982

        if dims == 1:
            s = Series(np.arange(10))
        else:
            s = DataFrame(np.arange(100).reshape(10, 10))

        with pytest.raises(TypeError, match="Cannot index by location index"):
            s.iloc["a"]

    def test_iloc_array_not_mutating_negative_indices(self):

        # GH 21867
        array_with_neg_numbers = np.array([1, 2, -1])
        array_copy = array_with_neg_numbers.copy()
        df = pd.DataFrame(
            {"A": [100, 101, 102], "B": [103, 104, 105], "C": [106, 107, 108]},
            index=[1, 2, 3],
        )
        df.iloc[array_with_neg_numbers]
        tm.assert_numpy_array_equal(array_with_neg_numbers, array_copy)
        df.iloc[:, array_with_neg_numbers]
        tm.assert_numpy_array_equal(array_with_neg_numbers, array_copy)

    def test_iloc_getitem_neg_int_can_reach_first_index(self):
        # GH10547 and GH10779
        # negative integers should be able to reach index 0
        df = DataFrame({"A": [2, 3, 5], "B": [7, 11, 13]})
        s = df["A"]

        expected = df.iloc[0]
        result = df.iloc[-3]
        tm.assert_series_equal(result, expected)

        expected = df.iloc[[0]]
        result = df.iloc[[-3]]
        tm.assert_frame_equal(result, expected)

        expected = s.iloc[0]
        result = s.iloc[-3]
        assert result == expected

        expected = s.iloc[[0]]
        result = s.iloc[[-3]]
        tm.assert_series_equal(result, expected)

        # check the length 1 Series case highlighted in GH10547
        expected = Series(["a"], index=["A"])
        result = expected.iloc[[-1]]
        tm.assert_series_equal(result, expected)

    def test_iloc_getitem_dups(self):
        # GH 6766
        df1 = DataFrame([{"A": None, "B": 1}, {"A": 2, "B": 2}])
        df2 = DataFrame([{"A": 3, "B": 3}, {"A": 4, "B": 4}])
        df = concat([df1, df2], axis=1)

        # cross-sectional indexing
        result = df.iloc[0, 0]
        assert isna(result)

        result = df.iloc[0, :]
        expected = Series([np.nan, 1, 3, 3], index=["A", "B", "A", "B"], name=0)
        tm.assert_series_equal(result, expected)

    def test_iloc_getitem_array(self):
        # TODO: test something here?
        pass

    def test_iloc_getitem_bool(self):
        # TODO: test something here?
        pass

    @pytest.mark.parametrize("index", [[True, False], [True, False, True, False]])
    def test_iloc_getitem_bool_diff_len(self, index):
        # GH26658
        s = Series([1, 2, 3])
        msg = f"Boolean index has wrong length: {len(index)} instead of {len(s)}"
        with pytest.raises(IndexError, match=msg):
            _ = s.iloc[index]

    def test_iloc_getitem_slice(self):
        # TODO: test something here?
        pass

    def test_iloc_getitem_slice_dups(self):

        df1 = DataFrame(np.random.randn(10, 4), columns=["A", "A", "B", "B"])
        df2 = DataFrame(
            np.random.randint(0, 10, size=20).reshape(10, 2), columns=["A", "C"]
        )

        # axis=1
        df = concat([df1, df2], axis=1)
        tm.assert_frame_equal(df.iloc[:, :4], df1)
        tm.assert_frame_equal(df.iloc[:, 4:], df2)

        df = concat([df2, df1], axis=1)
        tm.assert_frame_equal(df.iloc[:, :2], df2)
        tm.assert_frame_equal(df.iloc[:, 2:], df1)

        exp = concat([df2, df1.iloc[:, [0]]], axis=1)
        tm.assert_frame_equal(df.iloc[:, 0:3], exp)

        # axis=0
        df = concat([df, df], axis=0)
        tm.assert_frame_equal(df.iloc[0:10, :2], df2)
        tm.assert_frame_equal(df.iloc[0:10, 2:], df1)
        tm.assert_frame_equal(df.iloc[10:, :2], df2)
        tm.assert_frame_equal(df.iloc[10:, 2:], df1)

    def test_iloc_setitem(self):
        df = DataFrame(
            np.random.randn(4, 4), index=np.arange(0, 8, 2), columns=np.arange(0, 12, 3)
        )

        df.iloc[1, 1] = 1
        result = df.iloc[1, 1]
        assert result == 1

        df.iloc[:, 2:3] = 0
        expected = df.iloc[:, 2:3]
        result = df.iloc[:, 2:3]
        tm.assert_frame_equal(result, expected)

        # GH5771
        s = Series(0, index=[4, 5, 6])
        s.iloc[1:2] += 1
        expected = Series([0, 1, 0], index=[4, 5, 6])
        tm.assert_series_equal(s, expected)

    def test_iloc_setitem_list(self):

        # setitem with an iloc list
        df = DataFrame(
            np.arange(9).reshape((3, 3)), index=["A", "B", "C"], columns=["A", "B", "C"]
        )
        df.iloc[[0, 1], [1, 2]]
        df.iloc[[0, 1], [1, 2]] += 100

        expected = DataFrame(
            np.array([0, 101, 102, 3, 104, 105, 6, 7, 8]).reshape((3, 3)),
            index=["A", "B", "C"],
            columns=["A", "B", "C"],
        )
        tm.assert_frame_equal(df, expected)

    def test_iloc_setitem_pandas_object(self):
        # GH 17193
        s_orig = Series([0, 1, 2, 3])
        expected = Series([0, -1, -2, 3])

        s = s_orig.copy()
        s.iloc[Series([1, 2])] = [-1, -2]
        tm.assert_series_equal(s, expected)

        s = s_orig.copy()
        s.iloc[pd.Index([1, 2])] = [-1, -2]
        tm.assert_series_equal(s, expected)

    def test_iloc_setitem_dups(self):

        # GH 6766
        # iloc with a mask aligning from another iloc
        df1 = DataFrame([{"A": None, "B": 1}, {"A": 2, "B": 2}])
        df2 = DataFrame([{"A": 3, "B": 3}, {"A": 4, "B": 4}])
        df = concat([df1, df2], axis=1)

        expected = df.fillna(3)
        inds = np.isnan(df.iloc[:, 0])
        mask = inds[inds].index
        df.iloc[mask, 0] = df.iloc[mask, 2]
        tm.assert_frame_equal(df, expected)

        # del a dup column across blocks
        expected = DataFrame({0: [1, 2], 1: [3, 4]})
        expected.columns = ["B", "B"]
        del df["A"]
        tm.assert_frame_equal(df, expected)

        # assign back to self
        df.iloc[[0, 1], [0, 1]] = df.iloc[[0, 1], [0, 1]]
        tm.assert_frame_equal(df, expected)

        # reversed x 2
        df.iloc[[1, 0], [0, 1]] = df.iloc[[1, 0], [0, 1]].reset_index(drop=True)
        df.iloc[[1, 0], [0, 1]] = df.iloc[[1, 0], [0, 1]].reset_index(drop=True)
        tm.assert_frame_equal(df, expected)

    # TODO: GH#27620 this test used to compare iloc against ix; check if this
    #  is redundant with another test comparing iloc against loc
    def test_iloc_getitem_frame(self):
        df = DataFrame(
            np.random.randn(10, 4), index=range(0, 20, 2), columns=range(0, 8, 2)
        )

        result = df.iloc[2]
        exp = df.loc[4]
        tm.assert_series_equal(result, exp)

        result = df.iloc[2, 2]
        exp = df.loc[4, 4]
        assert result == exp

        # slice
        result = df.iloc[4:8]
        expected = df.loc[8:14]
        tm.assert_frame_equal(result, expected)

        result = df.iloc[:, 2:3]
        expected = df.loc[:, 4:5]
        tm.assert_frame_equal(result, expected)

        # list of integers
        result = df.iloc[[0, 1, 3]]
        expected = df.loc[[0, 2, 6]]
        tm.assert_frame_equal(result, expected)

        result = df.iloc[[0, 1, 3], [0, 1]]
        expected = df.loc[[0, 2, 6], [0, 2]]
        tm.assert_frame_equal(result, expected)

        # neg indices
        result = df.iloc[[-1, 1, 3], [-1, 1]]
        expected = df.loc[[18, 2, 6], [6, 2]]
        tm.assert_frame_equal(result, expected)

        # dups indices
        result = df.iloc[[-1, -1, 1, 3], [-1, 1]]
        expected = df.loc[[18, 18, 2, 6], [6, 2]]
        tm.assert_frame_equal(result, expected)

        # with index-like
        s = Series(index=range(1, 5), dtype=object)
        result = df.iloc[s.index]
        expected = df.loc[[2, 4, 6, 8]]
        tm.assert_frame_equal(result, expected)

    def test_iloc_getitem_labelled_frame(self):
        # try with labelled frame
        df = DataFrame(
            np.random.randn(10, 4), index=list("abcdefghij"), columns=list("ABCD")
        )

        result = df.iloc[1, 1]
        exp = df.loc["b", "B"]
        assert result == exp

        result = df.iloc[:, 2:3]
        expected = df.loc[:, ["C"]]
        tm.assert_frame_equal(result, expected)

        # negative indexing
        result = df.iloc[-1, -1]
        exp = df.loc["j", "D"]
        assert result == exp

        # out-of-bounds exception
        msg = "single positional indexer is out-of-bounds"
        with pytest.raises(IndexError, match=msg):
            df.iloc[10, 5]

        # trying to use a label
        msg = (
            r"Location based indexing can only have \[integer, integer "
            r"slice \(START point is INCLUDED, END point is EXCLUDED\), "
            r"listlike of integers, boolean array\] types"
        )
        with pytest.raises(ValueError, match=msg):
            df.iloc["j", "D"]

    def test_iloc_getitem_doc_issue(self):

        # multi axis slicing issue with single block
        # surfaced in GH 6059

        arr = np.random.randn(6, 4)
        index = date_range("20130101", periods=6)
        columns = list("ABCD")
        df = DataFrame(arr, index=index, columns=columns)

        # defines ref_locs
        df.describe()

        result = df.iloc[3:5, 0:2]
        str(result)
        result.dtypes

        expected = DataFrame(arr[3:5, 0:2], index=index[3:5], columns=columns[0:2])
        tm.assert_frame_equal(result, expected)

        # for dups
        df.columns = list("aaaa")
        result = df.iloc[3:5, 0:2]
        str(result)
        result.dtypes

        expected = DataFrame(arr[3:5, 0:2], index=index[3:5], columns=list("aa"))
        tm.assert_frame_equal(result, expected)

        # related
        arr = np.random.randn(6, 4)
        index = list(range(0, 12, 2))
        columns = list(range(0, 8, 2))
        df = DataFrame(arr, index=index, columns=columns)

        df._mgr.blocks[0].mgr_locs
        result = df.iloc[1:5, 2:4]
        str(result)
        result.dtypes
        expected = DataFrame(arr[1:5, 2:4], index=index[1:5], columns=columns[2:4])
        tm.assert_frame_equal(result, expected)

    def test_iloc_setitem_series(self):
        df = DataFrame(
            np.random.randn(10, 4), index=list("abcdefghij"), columns=list("ABCD")
        )

        df.iloc[1, 1] = 1
        result = df.iloc[1, 1]
        assert result == 1

        df.iloc[:, 2:3] = 0
        expected = df.iloc[:, 2:3]
        result = df.iloc[:, 2:3]
        tm.assert_frame_equal(result, expected)

        s = Series(np.random.randn(10), index=range(0, 20, 2))

        s.iloc[1] = 1
        result = s.iloc[1]
        assert result == 1

        s.iloc[:4] = 0
        expected = s.iloc[:4]
        result = s.iloc[:4]
        tm.assert_series_equal(result, expected)

        s = Series([-1] * 6)
        s.iloc[0::2] = [0, 2, 4]
        s.iloc[1::2] = [1, 3, 5]
        result = s
        expected = Series([0, 1, 2, 3, 4, 5])
        tm.assert_series_equal(result, expected)

    def test_iloc_setitem_list_of_lists(self):

        # GH 7551
        # list-of-list is set incorrectly in mixed vs. single dtyped frames
        df = DataFrame(
            dict(A=np.arange(5, dtype="int64"), B=np.arange(5, 10, dtype="int64"))
        )
        df.iloc[2:4] = [[10, 11], [12, 13]]
        expected = DataFrame(dict(A=[0, 1, 10, 12, 4], B=[5, 6, 11, 13, 9]))
        tm.assert_frame_equal(df, expected)

        df = DataFrame(dict(A=list("abcde"), B=np.arange(5, 10, dtype="int64")))
        df.iloc[2:4] = [["x", 11], ["y", 13]]
        expected = DataFrame(dict(A=["a", "b", "x", "y", "e"], B=[5, 6, 11, 13, 9]))
        tm.assert_frame_equal(df, expected)

    @pytest.mark.parametrize("indexer", [[0], slice(None, 1, None), np.array([0])])
    @pytest.mark.parametrize("value", [["Z"], np.array(["Z"])])
    def test_iloc_setitem_with_scalar_index(self, indexer, value):
        # GH #19474
        # assigning like "df.iloc[0, [0]] = ['Z']" should be evaluated
        # elementwisely, not using "setter('A', ['Z'])".

        df = pd.DataFrame([[1, 2], [3, 4]], columns=["A", "B"])
        df.iloc[0, indexer] = value
        result = df.iloc[0, 0]

        assert is_scalar(result) and result == "Z"

    def test_iloc_mask(self):

        # GH 3631, iloc with a mask (of a series) should raise
        df = DataFrame(list(range(5)), index=list("ABCDE"), columns=["a"])
        mask = df.a % 2 == 0
        msg = "iLocation based boolean indexing cannot use an indexable as a mask"
        with pytest.raises(ValueError, match=msg):
            df.iloc[mask]
        mask.index = range(len(mask))
        msg = "iLocation based boolean indexing on an integer type is not available"
        with pytest.raises(NotImplementedError, match=msg):
            df.iloc[mask]

        # ndarray ok
        result = df.iloc[np.array([True] * len(mask), dtype=bool)]
        tm.assert_frame_equal(result, df)

        # the possibilities
        locs = np.arange(4)
        nums = 2 ** locs
        reps = [bin(num) for num in nums]
        df = DataFrame({"locs": locs, "nums": nums}, reps)

        expected = {
            (None, ""): "0b1100",
            (None, ".loc"): "0b1100",
            (None, ".iloc"): "0b1100",
            ("index", ""): "0b11",
            ("index", ".loc"): "0b11",
            ("index", ".iloc"): (
                "iLocation based boolean indexing cannot use an indexable as a mask"
            ),
            ("locs", ""): "Unalignable boolean Series provided as indexer "
            "(index of the boolean Series and of the indexed "
            "object do not match).",
            ("locs", ".loc"): "Unalignable boolean Series provided as indexer "
            "(index of the boolean Series and of the "
            "indexed object do not match).",
            ("locs", ".iloc"): (
                "iLocation based boolean indexing on an "
                "integer type is not available"
            ),
        }

        # UserWarnings from reindex of a boolean mask
        with catch_warnings(record=True):
            simplefilter("ignore", UserWarning)
            result = dict()
            for idx in [None, "index", "locs"]:
                mask = (df.nums > 2).values
                if idx:
                    mask = Series(mask, list(reversed(getattr(df, idx))))
                for method in ["", ".loc", ".iloc"]:
                    try:
                        if method:
                            accessor = getattr(df, method[1:])
                        else:
                            accessor = df
                        ans = str(bin(accessor[mask]["nums"].sum()))
                    except (ValueError, IndexingError, NotImplementedError) as e:
                        ans = str(e)

                    key = tuple([idx, method])
                    r = expected.get(key)
                    if r != ans:
                        raise AssertionError(
                            f"[{key}] does not match [{ans}], received [{r}]"
                        )

    def test_iloc_non_unique_indexing(self):

        # GH 4017, non-unique indexing (on the axis)
        df = DataFrame({"A": [0.1] * 3000, "B": [1] * 3000})
        idx = np.arange(30) * 99
        expected = df.iloc[idx]

        df3 = concat([df, 2 * df, 3 * df])
        result = df3.iloc[idx]

        tm.assert_frame_equal(result, expected)

        df2 = DataFrame({"A": [0.1] * 1000, "B": [1] * 1000})
        df2 = concat([df2, 2 * df2, 3 * df2])

        with pytest.raises(KeyError, match="with any missing labels"):
            df2.loc[idx]

    def test_iloc_empty_list_indexer_is_ok(self):

        df = tm.makeCustomDataframe(5, 2)
        # vertical empty
        tm.assert_frame_equal(
            df.iloc[:, []],
            df.iloc[:, :0],
            check_index_type=True,
            check_column_type=True,
        )
        # horizontal empty
        tm.assert_frame_equal(
            df.iloc[[], :],
            df.iloc[:0, :],
            check_index_type=True,
            check_column_type=True,
        )
        # horizontal empty
        tm.assert_frame_equal(
            df.iloc[[]], 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.iloc[:]
        assert sliced_df is not original_df

        # should be a shallow copy
        original_df["a"] = [4, 4, 4]
        assert (sliced_df["a"] == 4).all()

        original_series = Series([1, 2, 3, 4, 5, 6])
        sliced_series = original_series.iloc[:]
        assert sliced_series is not original_series

        # should also be a shallow copy
        original_series[:3] = [7, 8, 9]
        assert all(sliced_series[:3] == [7, 8, 9])

    def test_indexing_zerodim_np_array(self):
        # GH24919
        df = DataFrame([[1, 2], [3, 4]])
        result = df.iloc[np.array(0)]
        s = pd.Series([1, 2], name=0)
        tm.assert_series_equal(result, s)

    def test_series_indexing_zerodim_np_array(self):
        # GH24919
        s = Series([1, 2])
        result = s.iloc[np.array(0)]
        assert result == 1

    @pytest.mark.xfail(reason="https://github.com/pandas-dev/pandas/issues/33457")
    def test_iloc_setitem_categorical_updates_inplace(self):
        # Mixed dtype ensures we go through take_split_path in setitem_with_indexer
        cat = pd.Categorical(["A", "B", "C"])
        df = pd.DataFrame({1: cat, 2: [1, 2, 3]})

        # This should modify our original values in-place
        df.iloc[:, 0] = cat[::-1]

        expected = pd.Categorical(["C", "B", "A"])
        tm.assert_categorical_equal(cat, expected)

    def test_iloc_with_boolean_operation(self):
        # GH 20627
        result = DataFrame([[0, 1], [2, 3], [4, 5], [6, np.nan]])
        result.iloc[result.index <= 2] *= 2
        expected = DataFrame([[0, 2], [4, 6], [8, 10], [6, np.nan]])
        tm.assert_frame_equal(result, expected)

        result.iloc[result.index > 2] *= 2
        expected = DataFrame([[0, 2], [4, 6], [8, 10], [12, np.nan]])
        tm.assert_frame_equal(result, expected)

        result.iloc[[True, True, False, False]] *= 2
        expected = DataFrame([[0, 4], [8, 12], [8, 10], [12, np.nan]])
        tm.assert_frame_equal(result, expected)

        result.iloc[[False, False, True, True]] /= 2
        expected = DataFrame([[0.0, 4.0], [8.0, 12.0], [4.0, 5.0], [6.0, np.nan]])
        tm.assert_frame_equal(result, expected)


class TestILocSetItemDuplicateColumns:
    def test_iloc_setitem_scalar_duplicate_columns(self):
        # GH#15686, duplicate columns and mixed dtype
        df1 = pd.DataFrame([{"A": None, "B": 1}, {"A": 2, "B": 2}])
        df2 = pd.DataFrame([{"A": 3, "B": 3}, {"A": 4, "B": 4}])
        df = pd.concat([df1, df2], axis=1)
        df.iloc[0, 0] = -1

        assert df.iloc[0, 0] == -1
        assert df.iloc[0, 2] == 3
        assert df.dtypes.iloc[2] == np.int64

    def test_iloc_setitem_list_duplicate_columns(self):
        # GH#22036 setting with same-sized list
        df = pd.DataFrame([[0, "str", "str2"]], columns=["a", "b", "b"])

        df.iloc[:, 2] = ["str3"]

        expected = pd.DataFrame([[0, "str", "str3"]], columns=["a", "b", "b"])
        tm.assert_frame_equal(df, expected)

    def test_iloc_setitem_series_duplicate_columns(self):
        df = pd.DataFrame(
            np.arange(8, dtype=np.int64).reshape(2, 4), columns=["A", "B", "A", "B"]
        )
        df.iloc[:, 0] = df.iloc[:, 0].astype(np.float64)
        assert df.dtypes.iloc[2] == np.int64