forked from dask/dask
-
Notifications
You must be signed in to change notification settings - Fork 0
/
test_parquet.py
4283 lines (3586 loc) · 139 KB
/
test_parquet.py
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
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
import glob
import math
import os
import sys
import warnings
from decimal import Decimal
from unittest.mock import MagicMock
import numpy as np
import pandas as pd
import pytest
from packaging.version import parse as parse_version
import dask
import dask.dataframe as dd
import dask.multiprocessing
from dask.blockwise import Blockwise, optimize_blockwise
from dask.dataframe._compat import PANDAS_GT_110, PANDAS_GT_121, PANDAS_GT_130
from dask.dataframe.io.parquet.core import get_engine
from dask.dataframe.io.parquet.utils import _parse_pandas_metadata
from dask.dataframe.optimize import optimize_dataframe_getitem
from dask.dataframe.utils import assert_eq
from dask.layers import DataFrameIOLayer
from dask.utils import natural_sort_key
from dask.utils_test import hlg_layer
try:
import fastparquet
except ImportError:
fastparquet = False
fastparquet_version = parse_version("0")
else:
fastparquet_version = parse_version(fastparquet.__version__)
try:
import pyarrow as pa
except ImportError:
pa = False
pa_version = parse_version("0")
else:
pa_version = parse_version(pa.__version__)
try:
import pyarrow.parquet as pq
except ImportError:
pq = False
SKIP_FASTPARQUET = not fastparquet
FASTPARQUET_MARK = pytest.mark.skipif(SKIP_FASTPARQUET, reason="fastparquet not found")
if sys.platform == "win32" and pa and pa_version == parse_version("2.0.0"):
SKIP_PYARROW = True
SKIP_PYARROW_REASON = (
"skipping pyarrow 2.0.0 on windows: "
"https://github.com/dask/dask/issues/6093"
"|https://github.com/dask/dask/issues/6754"
)
else:
SKIP_PYARROW = not pq
SKIP_PYARROW_REASON = "pyarrow not found"
PYARROW_MARK = pytest.mark.skipif(SKIP_PYARROW, reason=SKIP_PYARROW_REASON)
nrows = 40
npartitions = 15
df = pd.DataFrame(
{
"x": [i * 7 % 5 for i in range(nrows)], # Not sorted
"y": [i * 2.5 for i in range(nrows)], # Sorted
},
index=pd.Index([10 * i for i in range(nrows)], name="myindex"),
)
ddf = dd.from_pandas(df, npartitions=npartitions)
@pytest.fixture(
params=[
pytest.param("fastparquet", marks=FASTPARQUET_MARK),
pytest.param("pyarrow", marks=PYARROW_MARK),
]
)
def engine(request):
return request.param
def write_read_engines(**kwargs):
"""Product of both engines for write/read:
To add custom marks, pass keyword of the form: `mark_writer_reader=reason`,
or `mark_engine=reason` to apply to all parameters with that engine."""
backends = {"pyarrow", "fastparquet"}
# Skip if uninstalled
skip_marks = {
"fastparquet": FASTPARQUET_MARK,
"pyarrow": PYARROW_MARK,
}
marks = {(w, r): [skip_marks[w], skip_marks[r]] for w in backends for r in backends}
# Custom marks
for kw, val in kwargs.items():
kind, rest = kw.split("_", 1)
key = tuple(rest.split("_"))
if kind not in ("xfail", "skip") or len(key) > 2 or set(key) - backends:
raise ValueError("unknown keyword %r" % kw)
val = getattr(pytest.mark, kind)(reason=val)
if len(key) == 2:
marks[key].append(val)
else:
for k in marks:
if key in k:
marks[k].append(val)
return pytest.mark.parametrize(
("write_engine", "read_engine"),
[pytest.param(*k, marks=tuple(v)) for (k, v) in sorted(marks.items())],
)
if (
fastparquet
and fastparquet_version < parse_version("0.5")
and PANDAS_GT_110
and not PANDAS_GT_121
):
# a regression in pandas 1.1.x / 1.2.0 caused a failure in writing partitioned
# categorical columns when using fastparquet 0.4.x, but this was (accidentally)
# fixed in fastparquet 0.5.0
fp_pandas_msg = "pandas with fastparquet engine does not preserve index"
pyarrow_fastparquet_msg = "pyarrow schema and pandas metadata may disagree"
fp_pandas_xfail = write_read_engines(
**{
"xfail_pyarrow_fastparquet": pyarrow_fastparquet_msg,
"xfail_fastparquet_fastparquet": fp_pandas_msg,
"xfail_fastparquet_pyarrow": fp_pandas_msg,
}
)
else:
fp_pandas_xfail = write_read_engines()
@PYARROW_MARK
def test_get_engine_pyarrow():
from dask.dataframe.io.parquet.arrow import ArrowDatasetEngine
assert get_engine("pyarrow") == ArrowDatasetEngine
assert get_engine("arrow") == ArrowDatasetEngine
@FASTPARQUET_MARK
def test_get_engine_fastparquet():
from dask.dataframe.io.parquet.fastparquet import FastParquetEngine
assert get_engine("fastparquet") == FastParquetEngine
@write_read_engines()
@pytest.mark.parametrize("has_metadata", [False, True])
def test_local(tmpdir, write_engine, read_engine, has_metadata):
tmp = str(tmpdir)
data = pd.DataFrame(
{
"i32": np.arange(1000, dtype=np.int32),
"i64": np.arange(1000, dtype=np.int64),
"f": np.arange(1000, dtype=np.float64),
"bhello": np.random.choice(["hello", "yo", "people"], size=1000).astype(
"O"
),
}
)
df = dd.from_pandas(data, chunksize=500)
kwargs = {"write_metadata_file": True} if has_metadata else {}
df.to_parquet(tmp, write_index=False, engine=write_engine, **kwargs)
files = os.listdir(tmp)
assert ("_common_metadata" in files) == has_metadata
assert ("_metadata" in files) == has_metadata
assert "part.0.parquet" in files
df2 = dd.read_parquet(tmp, index=False, engine=read_engine)
assert len(df2.divisions) > 1
out = df2.compute(scheduler="sync").reset_index()
for column in df.columns:
assert (data[column] == out[column]).all()
@pytest.mark.parametrize("index", [False, True])
@write_read_engines()
def test_empty(tmpdir, write_engine, read_engine, index):
fn = str(tmpdir)
df = pd.DataFrame({"a": ["a", "b", "b"], "b": [4, 5, 6]})[:0]
if index:
df = df.set_index("a", drop=True)
ddf = dd.from_pandas(df, npartitions=2)
ddf.to_parquet(fn, write_index=index, engine=write_engine, write_metadata_file=True)
read_df = dd.read_parquet(fn, engine=read_engine)
assert_eq(ddf, read_df)
@write_read_engines()
def test_simple(tmpdir, write_engine, read_engine):
fn = str(tmpdir)
df = pd.DataFrame({"a": ["a", "b", "b"], "b": [4, 5, 6]})
df = df.set_index("a", drop=True)
ddf = dd.from_pandas(df, npartitions=2)
ddf.to_parquet(fn, engine=write_engine)
read_df = dd.read_parquet(
fn, index=["a"], engine=read_engine, calculate_divisions=True
)
assert_eq(ddf, read_df)
@write_read_engines()
def test_delayed_no_metadata(tmpdir, write_engine, read_engine):
fn = str(tmpdir)
df = pd.DataFrame({"a": ["a", "b", "b"], "b": [4, 5, 6]})
df = df.set_index("a", drop=True)
ddf = dd.from_pandas(df, npartitions=2)
ddf.to_parquet(
fn, engine=write_engine, compute=False, write_metadata_file=False
).compute()
files = os.listdir(fn)
assert "_metadata" not in files
# Fastparquet doesn't currently handle a directory without "_metadata"
read_df = dd.read_parquet(
os.path.join(fn, "*.parquet"),
index=["a"],
engine=read_engine,
calculate_divisions=True,
)
assert_eq(ddf, read_df)
@write_read_engines()
def test_read_glob(tmpdir, write_engine, read_engine):
tmp_path = str(tmpdir)
ddf.to_parquet(tmp_path, engine=write_engine)
if os.path.exists(os.path.join(tmp_path, "_metadata")):
os.unlink(os.path.join(tmp_path, "_metadata"))
files = os.listdir(tmp_path)
assert "_metadata" not in files
ddf2 = dd.read_parquet(
os.path.join(tmp_path, "*.parquet"),
engine=read_engine,
index="myindex", # Must specify index without _metadata
calculate_divisions=True,
)
assert_eq(ddf, ddf2)
@write_read_engines()
def test_calculate_divisions_false(tmpdir, write_engine, read_engine):
tmp_path = str(tmpdir)
ddf.to_parquet(tmp_path, write_index=False, engine=write_engine)
ddf2 = dd.read_parquet(
tmp_path,
engine=read_engine,
index=False,
calculate_divisions=False,
)
assert_eq(ddf, ddf2, check_index=False, check_divisions=False)
@write_read_engines()
def test_read_list(tmpdir, write_engine, read_engine):
if write_engine == read_engine == "fastparquet" and os.name == "nt":
# fastparquet or dask is not normalizing filepaths correctly on
# windows.
pytest.skip("filepath bug.")
tmpdir = str(tmpdir)
ddf.to_parquet(tmpdir, engine=write_engine)
files = sorted(
(
os.path.join(tmpdir, f)
for f in os.listdir(tmpdir)
if not f.endswith("_metadata")
),
key=natural_sort_key,
)
ddf2 = dd.read_parquet(
files, engine=read_engine, index="myindex", calculate_divisions=True
)
assert_eq(ddf, ddf2)
@write_read_engines()
def test_columns_auto_index(tmpdir, write_engine, read_engine):
fn = str(tmpdir)
ddf.to_parquet(fn, engine=write_engine)
# ### Empty columns ###
# With divisions if supported
assert_eq(
dd.read_parquet(fn, columns=[], engine=read_engine, calculate_divisions=True),
ddf[[]],
)
# No divisions
assert_eq(
dd.read_parquet(fn, columns=[], engine=read_engine, calculate_divisions=False),
ddf[[]].clear_divisions(),
check_divisions=True,
)
# ### Single column, auto select index ###
# With divisions if supported
assert_eq(
dd.read_parquet(
fn, columns=["x"], engine=read_engine, calculate_divisions=True
),
ddf[["x"]],
)
# No divisions
assert_eq(
dd.read_parquet(
fn, columns=["x"], engine=read_engine, calculate_divisions=False
),
ddf[["x"]].clear_divisions(),
check_divisions=True,
)
@write_read_engines()
def test_columns_index(tmpdir, write_engine, read_engine):
fn = str(tmpdir)
ddf.to_parquet(fn, engine=write_engine)
# With Index
# ----------
# ### Empty columns, specify index ###
# With divisions if supported
assert_eq(
dd.read_parquet(
fn,
columns=[],
engine=read_engine,
index="myindex",
calculate_divisions=True,
),
ddf[[]],
)
# No divisions
assert_eq(
dd.read_parquet(
fn,
columns=[],
engine=read_engine,
index="myindex",
calculate_divisions=False,
),
ddf[[]].clear_divisions(),
check_divisions=True,
)
# ### Single column, specify index ###
# With divisions if supported
assert_eq(
dd.read_parquet(
fn,
index="myindex",
columns=["x"],
engine=read_engine,
calculate_divisions=True,
),
ddf[["x"]],
)
# No divisions
assert_eq(
dd.read_parquet(
fn,
index="myindex",
columns=["x"],
engine=read_engine,
calculate_divisions=False,
),
ddf[["x"]].clear_divisions(),
check_divisions=True,
)
# ### Two columns, specify index ###
# With divisions if supported
assert_eq(
dd.read_parquet(
fn,
index="myindex",
columns=["x", "y"],
engine=read_engine,
calculate_divisions=True,
),
ddf,
)
# No divisions
assert_eq(
dd.read_parquet(
fn,
index="myindex",
columns=["x", "y"],
engine=read_engine,
calculate_divisions=False,
),
ddf.clear_divisions(),
check_divisions=True,
)
def test_nonsense_column(tmpdir, engine):
fn = str(tmpdir)
ddf.to_parquet(fn, engine=engine)
with pytest.raises((ValueError, KeyError)):
dd.read_parquet(fn, columns=["nonesense"], engine=engine)
with pytest.raises((Exception, KeyError)):
dd.read_parquet(fn, columns=["nonesense"] + list(ddf.columns), engine=engine)
@write_read_engines()
def test_columns_no_index(tmpdir, write_engine, read_engine):
fn = str(tmpdir)
ddf.to_parquet(fn, engine=write_engine)
ddf2 = ddf.reset_index()
# No Index
# --------
# All columns, none as index
assert_eq(
dd.read_parquet(fn, index=False, engine=read_engine, calculate_divisions=True),
ddf2,
check_index=False,
check_divisions=True,
)
# Two columns, none as index
assert_eq(
dd.read_parquet(
fn,
index=False,
columns=["x", "y"],
engine=read_engine,
calculate_divisions=True,
),
ddf2[["x", "y"]],
check_index=False,
check_divisions=True,
)
# One column and one index, all as columns
assert_eq(
dd.read_parquet(
fn,
index=False,
columns=["myindex", "x"],
engine=read_engine,
calculate_divisions=True,
),
ddf2[["myindex", "x"]],
check_index=False,
check_divisions=True,
)
@write_read_engines()
def test_calculate_divisions_no_index(tmpdir, write_engine, read_engine):
fn = str(tmpdir)
ddf.to_parquet(fn, engine=write_engine, write_index=False)
df = dd.read_parquet(fn, engine=read_engine, index=False)
assert df.index.name is None
assert not df.known_divisions
def test_columns_index_with_multi_index(tmpdir, engine):
fn = os.path.join(str(tmpdir), "test.parquet")
index = pd.MultiIndex.from_arrays(
[np.arange(10), np.arange(10) + 1], names=["x0", "x1"]
)
df = pd.DataFrame(np.random.randn(10, 2), columns=["a", "b"], index=index)
df2 = df.reset_index(drop=False)
if engine == "fastparquet":
fastparquet.write(fn, df.reset_index(), write_index=False)
else:
pq.write_table(pa.Table.from_pandas(df.reset_index(), preserve_index=False), fn)
ddf = dd.read_parquet(fn, engine=engine, index=index.names)
assert_eq(ddf, df)
d = dd.read_parquet(fn, columns="a", engine=engine, index=index.names)
assert_eq(d, df["a"])
d = dd.read_parquet(fn, index=["a", "b"], columns=["x0", "x1"], engine=engine)
assert_eq(d, df2.set_index(["a", "b"])[["x0", "x1"]])
# Just index
d = dd.read_parquet(fn, index=False, engine=engine)
assert_eq(d, df2)
d = dd.read_parquet(fn, columns=["b"], index=["a"], engine=engine)
assert_eq(d, df2.set_index("a")[["b"]])
d = dd.read_parquet(fn, columns=["a", "b"], index=["x0"], engine=engine)
assert_eq(d, df2.set_index("x0")[["a", "b"]])
# Just columns
d = dd.read_parquet(fn, columns=["x0", "a"], index=["x1"], engine=engine)
assert_eq(d, df2.set_index("x1")[["x0", "a"]])
# Both index and columns
d = dd.read_parquet(fn, index=False, columns=["x0", "b"], engine=engine)
assert_eq(d, df2[["x0", "b"]])
for index in ["x1", "b"]:
d = dd.read_parquet(fn, index=index, columns=["x0", "a"], engine=engine)
assert_eq(d, df2.set_index(index)[["x0", "a"]])
# Columns and index intersect
for index in ["a", "x0"]:
with pytest.raises(ValueError):
d = dd.read_parquet(fn, index=index, columns=["x0", "a"], engine=engine)
# Series output
for ind, col, sol_df in [
("x1", "x0", df2.set_index("x1")),
(False, "b", df2),
(False, "x0", df2[["x0"]]),
("a", "x0", df2.set_index("a")[["x0"]]),
("a", "b", df2.set_index("a")),
]:
d = dd.read_parquet(fn, index=ind, columns=col, engine=engine)
assert_eq(d, sol_df[col])
@write_read_engines()
def test_no_index(tmpdir, write_engine, read_engine):
fn = str(tmpdir)
df = pd.DataFrame({"a": [1, 2, 3], "b": [4, 5, 6]})
ddf = dd.from_pandas(df, npartitions=2)
ddf.to_parquet(fn, engine=write_engine)
ddf2 = dd.read_parquet(fn, engine=read_engine)
assert_eq(df, ddf2, check_index=False)
def test_read_series(tmpdir, engine):
fn = str(tmpdir)
ddf.to_parquet(fn, engine=engine)
ddf2 = dd.read_parquet(
fn, columns=["x"], index="myindex", engine=engine, calculate_divisions=True
)
assert_eq(ddf[["x"]], ddf2)
ddf2 = dd.read_parquet(
fn, columns="x", index="myindex", engine=engine, calculate_divisions=True
)
assert_eq(ddf.x, ddf2)
def test_names(tmpdir, engine):
fn = str(tmpdir)
ddf.to_parquet(fn, engine=engine)
def read(fn, **kwargs):
return dd.read_parquet(fn, engine=engine, **kwargs)
assert set(read(fn).dask) == set(read(fn).dask)
assert set(read(fn).dask) != set(read(fn, columns=["x"]).dask)
assert set(read(fn, columns=("x",)).dask) == set(read(fn, columns=["x"]).dask)
@write_read_engines()
def test_roundtrip_from_pandas(tmpdir, write_engine, read_engine):
fn = str(tmpdir.join("test.parquet"))
dfp = df.copy()
dfp.index.name = "index"
dfp.to_parquet(
fn, engine="pyarrow" if write_engine.startswith("pyarrow") else "fastparquet"
)
ddf = dd.read_parquet(fn, index="index", engine=read_engine)
assert_eq(dfp, ddf)
@write_read_engines()
def test_categorical(tmpdir, write_engine, read_engine):
tmp = str(tmpdir)
df = pd.DataFrame({"x": ["a", "b", "c"] * 100}, dtype="category")
ddf = dd.from_pandas(df, npartitions=3)
dd.to_parquet(ddf, tmp, engine=write_engine)
ddf2 = dd.read_parquet(tmp, categories="x", engine=read_engine)
assert ddf2.compute().x.cat.categories.tolist() == ["a", "b", "c"]
ddf2 = dd.read_parquet(tmp, categories=["x"], engine=read_engine)
assert ddf2.compute().x.cat.categories.tolist() == ["a", "b", "c"]
# autocat
if read_engine == "fastparquet":
ddf2 = dd.read_parquet(tmp, engine=read_engine)
assert ddf2.compute().x.cat.categories.tolist() == ["a", "b", "c"]
ddf2.loc[:1000].compute()
assert assert_eq(df, ddf2)
# dereference cats
ddf2 = dd.read_parquet(tmp, categories=[], engine=read_engine)
ddf2.loc[:1000].compute()
assert (df.x == ddf2.x.compute()).all()
@pytest.mark.parametrize("metadata_file", [False, True])
def test_append(tmpdir, engine, metadata_file):
"""Test that appended parquet equal to the original one."""
tmp = str(tmpdir)
df = pd.DataFrame(
{
"i32": np.arange(1000, dtype=np.int32),
"i64": np.arange(1000, dtype=np.int64),
"f": np.arange(1000, dtype=np.float64),
"bhello": np.random.choice(["hello", "yo", "people"], size=1000).astype(
"O"
),
}
)
df.index.name = "index"
half = len(df) // 2
ddf1 = dd.from_pandas(df.iloc[:half], chunksize=100)
ddf2 = dd.from_pandas(df.iloc[half:], chunksize=100)
ddf1.to_parquet(tmp, engine=engine, write_metadata_file=metadata_file)
if metadata_file:
with open(str(tmpdir.join("_metadata")), "rb") as f:
metadata1 = f.read()
ddf2.to_parquet(tmp, append=True, engine=engine)
if metadata_file:
with open(str(tmpdir.join("_metadata")), "rb") as f:
metadata2 = f.read()
assert metadata2 != metadata1 # 2nd write updated the metadata file
ddf3 = dd.read_parquet(tmp, engine=engine)
assert_eq(df, ddf3)
def test_append_create(tmpdir, engine):
"""Test that appended parquet equal to the original one."""
tmp_path = str(tmpdir)
df = pd.DataFrame(
{
"i32": np.arange(1000, dtype=np.int32),
"i64": np.arange(1000, dtype=np.int64),
"f": np.arange(1000, dtype=np.float64),
"bhello": np.random.choice(["hello", "yo", "people"], size=1000).astype(
"O"
),
}
)
df.index.name = "index"
half = len(df) // 2
ddf1 = dd.from_pandas(df.iloc[:half], chunksize=100)
ddf2 = dd.from_pandas(df.iloc[half:], chunksize=100)
ddf1.to_parquet(tmp_path, append=True, engine=engine)
ddf2.to_parquet(tmp_path, append=True, engine=engine)
ddf3 = dd.read_parquet(tmp_path, engine=engine)
assert_eq(df, ddf3)
def test_append_with_partition(tmpdir, engine):
tmp = str(tmpdir)
df0 = pd.DataFrame(
{
"lat": np.arange(0, 10, dtype="int64"),
"lon": np.arange(10, 20, dtype="int64"),
"value": np.arange(100, 110, dtype="int64"),
}
)
df0.index.name = "index"
df1 = pd.DataFrame(
{
"lat": np.arange(10, 20, dtype="int64"),
"lon": np.arange(10, 20, dtype="int64"),
"value": np.arange(120, 130, dtype="int64"),
}
)
df1.index.name = "index"
# Check that nullable dtypes work
# (see: https://github.com/dask/dask/issues/8373)
df0["lat"] = df0["lat"].astype("Int64")
df1["lat"].iloc[0] = np.nan
df1["lat"] = df1["lat"].astype("Int64")
dd_df0 = dd.from_pandas(df0, npartitions=1)
dd_df1 = dd.from_pandas(df1, npartitions=1)
dd.to_parquet(dd_df0, tmp, partition_on=["lon"], engine=engine)
dd.to_parquet(
dd_df1,
tmp,
partition_on=["lon"],
append=True,
ignore_divisions=True,
engine=engine,
)
out = dd.read_parquet(
tmp, engine=engine, index="index", calculate_divisions=True
).compute()
# convert categorical to plain int just to pass assert
out["lon"] = out.lon.astype("int64")
# sort required since partitioning breaks index order
assert_eq(
out.sort_values("value"), pd.concat([df0, df1])[out.columns], check_index=False
)
def test_partition_on_cats(tmpdir, engine):
tmp = str(tmpdir)
d = pd.DataFrame(
{
"a": np.random.rand(50),
"b": np.random.choice(["x", "y", "z"], size=50),
"c": np.random.choice(["x", "y", "z"], size=50),
}
)
d = dd.from_pandas(d, 2)
d.to_parquet(tmp, partition_on=["b"], engine=engine)
df = dd.read_parquet(tmp, engine=engine)
assert set(df.b.cat.categories) == {"x", "y", "z"}
@PYARROW_MARK
@pytest.mark.parametrize("meta", [False, True])
@pytest.mark.parametrize("stats", [False, True])
def test_partition_on_cats_pyarrow(tmpdir, stats, meta):
tmp = str(tmpdir)
d = pd.DataFrame(
{
"a": np.random.rand(50),
"b": np.random.choice(["x", "y", "z"], size=50),
"c": np.random.choice(["x", "y", "z"], size=50),
}
)
d = dd.from_pandas(d, 2)
d.to_parquet(tmp, partition_on=["b"], engine="pyarrow", write_metadata_file=meta)
df = dd.read_parquet(tmp, engine="pyarrow", calculate_divisions=stats)
assert set(df.b.cat.categories) == {"x", "y", "z"}
def test_partition_parallel_metadata(tmpdir, engine):
# Check that parallel metadata collection works
# for hive-partitioned data
tmp = str(tmpdir)
d = pd.DataFrame(
{
"a": np.random.rand(50),
"b": np.random.choice(["x", "y", "z"], size=50),
"c": np.random.choice(["x", "y", "z"], size=50),
}
)
d = dd.from_pandas(d, 2)
d.to_parquet(tmp, partition_on=["b"], engine=engine, write_metadata_file=False)
df = dd.read_parquet(
tmp, engine=engine, calculate_divisions=True, metadata_task_size=1
)
assert set(df.b.cat.categories) == {"x", "y", "z"}
def test_partition_on_cats_2(tmpdir, engine):
tmp = str(tmpdir)
d = pd.DataFrame(
{
"a": np.random.rand(50),
"b": np.random.choice(["x", "y", "z"], size=50),
"c": np.random.choice(["x", "y", "z"], size=50),
}
)
d = dd.from_pandas(d, 2)
d.to_parquet(tmp, partition_on=["b", "c"], engine=engine)
df = dd.read_parquet(tmp, engine=engine)
assert set(df.b.cat.categories) == {"x", "y", "z"}
assert set(df.c.cat.categories) == {"x", "y", "z"}
df = dd.read_parquet(tmp, columns=["a", "c"], engine=engine)
assert set(df.c.cat.categories) == {"x", "y", "z"}
assert "b" not in df.columns
assert_eq(df, df.compute())
df = dd.read_parquet(tmp, index="c", engine=engine)
assert set(df.index.categories) == {"x", "y", "z"}
assert "c" not in df.columns
# series
df = dd.read_parquet(tmp, columns="b", engine=engine)
assert set(df.cat.categories) == {"x", "y", "z"}
@pytest.mark.parametrize("metadata_file", [False, True])
def test_append_wo_index(tmpdir, engine, metadata_file):
"""Test append with write_index=False."""
tmp = str(tmpdir.join("tmp1.parquet"))
df = pd.DataFrame(
{
"i32": np.arange(1000, dtype=np.int32),
"i64": np.arange(1000, dtype=np.int64),
"f": np.arange(1000, dtype=np.float64),
"bhello": np.random.choice(["hello", "yo", "people"], size=1000).astype(
"O"
),
}
)
half = len(df) // 2
ddf1 = dd.from_pandas(df.iloc[:half], chunksize=100)
ddf2 = dd.from_pandas(df.iloc[half:], chunksize=100)
ddf1.to_parquet(tmp, engine=engine, write_metadata_file=metadata_file)
with pytest.raises(ValueError) as excinfo:
ddf2.to_parquet(tmp, write_index=False, append=True, engine=engine)
assert "Appended columns" in str(excinfo.value)
tmp = str(tmpdir.join("tmp2.parquet"))
ddf1.to_parquet(
tmp, write_index=False, engine=engine, write_metadata_file=metadata_file
)
ddf2.to_parquet(tmp, write_index=False, append=True, engine=engine)
ddf3 = dd.read_parquet(tmp, index="f", engine=engine)
assert_eq(df.set_index("f"), ddf3)
@pytest.mark.parametrize("metadata_file", [False, True])
@pytest.mark.parametrize(
("index", "offset"),
[
(
# There is some odd behavior with date ranges and pyarrow in some cirucmstances!
# https://github.com/pandas-dev/pandas/issues/48573
pd.date_range("2022-01-01", "2022-01-31", freq="D"),
pd.Timedelta(days=1),
),
(pd.RangeIndex(0, 500, 1), 499),
],
)
def test_append_overlapping_divisions(tmpdir, engine, metadata_file, index, offset):
"""Test raising of error when divisions overlapping."""
tmp = str(tmpdir)
df = pd.DataFrame(
{
"i32": np.arange(len(index), dtype=np.int32),
"i64": np.arange(len(index), dtype=np.int64),
"f": np.arange(len(index), dtype=np.float64),
"bhello": np.random.choice(
["hello", "yo", "people"], size=len(index)
).astype("O"),
},
index=index,
)
ddf1 = dd.from_pandas(df, chunksize=100)
ddf2 = dd.from_pandas(df.set_index(df.index + offset), chunksize=100)
ddf1.to_parquet(tmp, engine=engine, write_metadata_file=metadata_file)
with pytest.raises(ValueError, match="overlap with previously written divisions"):
ddf2.to_parquet(tmp, engine=engine, append=True)
ddf2.to_parquet(tmp, engine=engine, append=True, ignore_divisions=True)
def test_append_known_divisions_to_unknown_divisions_works(tmpdir, engine):
tmp = str(tmpdir)
df1 = pd.DataFrame(
{"x": np.arange(100), "y": np.arange(100, 200)}, index=np.arange(100, 0, -1)
)
ddf1 = dd.from_pandas(df1, npartitions=3, sort=False)
df2 = pd.DataFrame({"x": np.arange(100, 200), "y": np.arange(200, 300)})
ddf2 = dd.from_pandas(df2, npartitions=3)
# fastparquet always loads all metadata when appending, pyarrow only does
# if a `_metadata` file exists. If we know the existing divisions aren't
# sorted, then we want to skip erroring for overlapping divisions. Setting
# `write_metadata_file=True` ensures this test works the same across both
# engines.
ddf1.to_parquet(tmp, engine=engine, write_metadata_file=True)
ddf2.to_parquet(tmp, engine=engine, append=True)
res = dd.read_parquet(tmp, engine=engine)
sol = pd.concat([df1, df2])
assert_eq(res, sol)
@pytest.mark.parametrize("metadata_file", [False, True])
def test_append_different_columns(tmpdir, engine, metadata_file):
"""Test raising of error when non equal columns."""
tmp = str(tmpdir)
df1 = pd.DataFrame({"i32": np.arange(100, dtype=np.int32)})
df2 = pd.DataFrame({"i64": np.arange(100, dtype=np.int64)})
df3 = pd.DataFrame({"i32": np.arange(100, dtype=np.int64)})
ddf1 = dd.from_pandas(df1, chunksize=2)
ddf2 = dd.from_pandas(df2, chunksize=2)
ddf3 = dd.from_pandas(df3, chunksize=2)
ddf1.to_parquet(tmp, engine=engine, write_metadata_file=metadata_file)
with pytest.raises(ValueError) as excinfo:
ddf2.to_parquet(tmp, engine=engine, append=True)
assert "Appended columns" in str(excinfo.value)
with pytest.raises(ValueError) as excinfo:
ddf3.to_parquet(tmp, engine=engine, append=True)
assert "Appended dtypes" in str(excinfo.value)
def test_append_dict_column(tmpdir, engine):
# See: https://github.com/dask/dask/issues/7492
if engine == "fastparquet":
pytest.xfail("Fastparquet engine is missing dict-column support")
elif pa_version < parse_version("1.0.1"):
pytest.skip("PyArrow 1.0.1+ required for dict-column support.")
tmp = str(tmpdir)
dts = pd.date_range("2020-01-01", "2021-01-01")
df = pd.DataFrame(
{"value": [{"x": x} for x in range(len(dts))]},
index=dts,
)
ddf1 = dd.from_pandas(df, npartitions=1)
schema = {"value": pa.struct([("x", pa.int32())])}
# Write ddf1 to tmp, and then append it again
ddf1.to_parquet(tmp, append=True, engine=engine, schema=schema)
ddf1.to_parquet(
tmp, append=True, engine=engine, schema=schema, ignore_divisions=True
)
# Read back all data (ddf1 + ddf1)
ddf2 = dd.read_parquet(tmp, engine=engine)
# Check computed result
expect = pd.concat([df, df])
result = ddf2.compute()
assert_eq(expect, result)
@write_read_engines()
def test_ordering(tmpdir, write_engine, read_engine):
tmp = str(tmpdir)
df = pd.DataFrame(
{"a": [1, 2, 3], "b": [10, 20, 30], "c": [100, 200, 300]},
index=pd.Index([-1, -2, -3], name="myindex"),
columns=["c", "a", "b"],
)
ddf = dd.from_pandas(df, npartitions=2)
dd.to_parquet(ddf, tmp, engine=write_engine)
ddf2 = dd.read_parquet(tmp, index="myindex", engine=read_engine)
assert_eq(ddf, ddf2, check_divisions=False)
def test_read_parquet_custom_columns(tmpdir, engine):
tmp = str(tmpdir)
data = pd.DataFrame(
{"i32": np.arange(1000, dtype=np.int32), "f": np.arange(1000, dtype=np.float64)}
)
df = dd.from_pandas(data, chunksize=50)
df.to_parquet(tmp, engine=engine)
df2 = dd.read_parquet(
tmp, columns=["i32", "f"], engine=engine, calculate_divisions=True
)
assert_eq(df[["i32", "f"]], df2, check_index=False)
fns = glob.glob(os.path.join(tmp, "*.parquet"))
df2 = dd.read_parquet(fns, columns=["i32"], engine=engine).compute()
df2.sort_values("i32", inplace=True)
assert_eq(df[["i32"]], df2, check_index=False, check_divisions=False)
df3 = dd.read_parquet(
tmp, columns=["f", "i32"], engine=engine, calculate_divisions=True
)
assert_eq(df[["f", "i32"]], df3, check_index=False)
@pytest.mark.parametrize(