Title: Lazy data files resolution
State: closed

Related to discussion at https://github.com/huggingface/datasets/pull/6255

this makes this code run in 2sec instead of >10sec

```python
from datasets import load_dataset

ds = load_dataset("glue", "sst2", streaming=True, trust_remote_code=False)
```

For some datasets with many configs and files it can be up to 100x faster.
This is particularly important now that some datasets will be loaded from the Parquet export instead of the scripts.

The data files are only resolved in the builder `__init__`. To do so I added DataFilesPatternsList and DataFilesPatternsDict that have `.resolve()` to return resolved DataFilesList and DataFilesDict

Comments:
<details>
<summary>Show benchmarks</summary>

PyArrow==8.0.0

<details>
<summary>Show updated benchmarks!</summary>

### Benchmark: benchmark_array_xd.json

| metric | read_batch_formatted_as_numpy after write_array2d | read_batch_formatted_as_numpy after write_flattened_sequence | read_batch_formatted_as_numpy after write_nested_sequence | read_batch_unformated after write_array2d | read_batch_unformated after write_flattened_sequence | read_batch_unformated after write_nested_sequence | read_col_formatted_as_numpy after write_array2d | read_col_formatted_as_numpy after write_flattened_sequence | read_col_formatted_as_numpy after write_nested_sequence | read_col_unformated after write_array2d | read_col_unformated after write_flattened_sequence | read_col_unformated after write_nested_sequence | read_formatted_as_numpy after write_array2d | read_formatted_as_numpy after write_flattened_sequence | read_formatted_as_numpy after write_nested_sequence | read_unformated after write_array2d | read_unformated after write_flattened_sequence | read_unformated after write_nested_sequence | write_array2d | write_flattened_sequence | write_nested_sequence |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.005097 / 0.011353 (-0.006256) | 0.003523 / 0.011008 (-0.007485) | 0.062827 / 0.038508 (0.024319) | 0.051677 / 0.023109 (0.028568) | 0.248919 / 0.275898 (-0.026980) | 0.275892 / 0.323480 (-0.047588) | 0.003908 / 0.007986 (-0.004077) | 0.002622 / 0.004328 (-0.001706) | 0.048634 / 0.004250 (0.044383) | 0.037903 / 0.037052 (0.000850) | 0.255754 / 0.258489 (-0.002735) | 0.283343 / 0.293841 (-0.010498) | 0.027886 / 0.128546 (-0.100660) | 0.010849 / 0.075646 (-0.064797) | 0.208255 / 0.419271 (-0.211017) | 0.035664 / 0.043533 (-0.007869) | 0.254661 / 0.255139 (-0.000478) | 0.274366 / 0.283200 (-0.008834) | 0.017240 / 0.141683 (-0.124443) | 1.092952 / 1.452155 (-0.359203) | 1.148373 / 1.492716 (-0.344344) |

### Benchmark: benchmark_getitem\_100B.json

| metric | get_batch_of\_1024\_random_rows | get_batch_of\_1024\_rows | get_first_row | get_last_row |
|--------|---|---|---|---|
| new / old (diff) | 0.091592 / 0.018006 (0.073586) | 0.301926 / 0.000490 (0.301436) | 0.000207 / 0.000200 (0.000007) | 0.000051 / 0.000054 (-0.000004) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.018525 / 0.037411 (-0.018887) | 0.060539 / 0.014526 (0.046014) | 0.073812 / 0.176557 (-0.102745) | 0.120655 / 0.737135 (-0.616480) | 0.076931 / 0.296338 (-0.219407) |

### Benchmark: benchmark_iterating.json

| metric | read 5000 | read 50000 | read_batch 50000 10 | read_batch 50000 100 | read_batch 50000 1000 | read_formatted numpy 5000 | read_formatted pandas 5000 | read_formatted tensorflow 5000 | read_formatted torch 5000 | read_formatted_batch numpy 5000 10 | read_formatted_batch numpy 5000 1000 | shuffled read 5000 | shuffled read 50000 | shuffled read_batch 50000 10 | shuffled read_batch 50000 100 | shuffled read_batch 50000 1000 | shuffled read_formatted numpy 5000 | shuffled read_formatted_batch numpy 5000 10 | shuffled read_formatted_batch numpy 5000 1000 |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.282797 / 0.215209 (0.067588) | 2.746573 / 2.077655 (0.668918) | 1.477652 / 1.504120 (-0.026468) | 1.349922 / 1.541195 (-0.191273) | 1.374347 / 1.468490 (-0.094143) | 0.574096 / 4.584777 (-4.010681) | 2.383317 / 3.745712 (-1.362395) | 2.809320 / 5.269862 (-2.460541) | 1.758947 / 4.565676 (-2.806729) | 0.064029 / 0.424275 (-0.360246) | 0.004936 / 0.007607 (-0.002672) | 0.331403 / 0.226044 (0.105358) | 3.260908 / 2.268929 (0.991980) | 1.817670 / 55.444624 (-53.626954) | 1.525863 / 6.876477 (-5.350613) | 1.542017 / 2.142072 (-0.600055) | 0.638900 / 4.805227 (-4.166327) | 0.119485 / 6.500664 (-6.381179) | 0.042588 / 0.075469 (-0.032881) |

### Benchmark: benchmark_map_filter.json

| metric | filter | map fast-tokenizer batched | map identity | map identity batched | map no-op batched | map no-op batched numpy | map no-op batched pandas | map no-op batched pytorch | map no-op batched tensorflow |
|--------|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.951583 / 1.841788 (-0.890205) | 11.621917 / 8.074308 (3.547609) | 10.511062 / 10.191392 (0.319670) | 0.130137 / 0.680424 (-0.550287) | 0.014048 / 0.534201 (-0.520153) | 0.290621 / 0.579283 (-0.288662) | 0.271665 / 0.434364 (-0.162699) | 0.331260 / 0.540337 (-0.209077) | 0.441621 / 1.386936 (-0.945316) |

</details>
PyArrow==latest

<details>
<summary>Show updated benchmarks!</summary>

### Benchmark: benchmark_array_xd.json

| metric | read_batch_formatted_as_numpy after write_array2d | read_batch_formatted_as_numpy after write_flattened_sequence | read_batch_formatted_as_numpy after write_nested_sequence | read_batch_unformated after write_array2d | read_batch_unformated after write_flattened_sequence | read_batch_unformated after write_nested_sequence | read_col_formatted_as_numpy after write_array2d | read_col_formatted_as_numpy after write_flattened_sequence | read_col_formatted_as_numpy after write_nested_sequence | read_col_unformated after write_array2d | read_col_unformated after write_flattened_sequence | read_col_unformated after write_nested_sequence | read_formatted_as_numpy after write_array2d | read_formatted_as_numpy after write_flattened_sequence | read_formatted_as_numpy after write_nested_sequence | read_unformated after write_array2d | read_unformated after write_flattened_sequence | read_unformated after write_nested_sequence | write_array2d | write_flattened_sequence | write_nested_sequence |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.005272 / 0.011353 (-0.006081) | 0.003656 / 0.011008 (-0.007352) | 0.049245 / 0.038508 (0.010737) | 0.054130 / 0.023109 (0.031021) | 0.274775 / 0.275898 (-0.001123) | 0.296664 / 0.323480 (-0.026816) | 0.004870 / 0.007986 (-0.003115) | 0.002728 / 0.004328 (-0.001601) | 0.048087 / 0.004250 (0.043837) | 0.041448 / 0.037052 (0.004396) | 0.279110 / 0.258489 (0.020621) | 0.303660 / 0.293841 (0.009819) | 0.029767 / 0.128546 (-0.098779) | 0.010799 / 0.075646 (-0.064848) | 0.058650 / 0.419271 (-0.360622) | 0.033088 / 0.043533 (-0.010445) | 0.274456 / 0.255139 (0.019317) | 0.290206 / 0.283200 (0.007007) | 0.017259 / 0.141683 (-0.124424) | 1.176501 / 1.452155 (-0.275654) | 1.197552 / 1.492716 (-0.295165) |

### Benchmark: benchmark_getitem\_100B.json

| metric | get_batch_of\_1024\_random_rows | get_batch_of\_1024\_rows | get_first_row | get_last_row |
|--------|---|---|---|---|
| new / old (diff) | 0.092865 / 0.018006 (0.074859) | 0.302437 / 0.000490 (0.301947) | 0.000209 / 0.000200 (0.000009) | 0.000048 / 0.000054 (-0.000006) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.021211 / 0.037411 (-0.016200) | 0.068858 / 0.014526 (0.054332) | 0.081783 / 0.176557 (-0.094773) | 0.120472 / 0.737135 (-0.616663) | 0.083900 / 0.296338 (-0.212438) |

### Benchmark: benchmark_iterating.json

| metric | read 5000 | read 50000 | read_batch 50000 10 | read_batch 50000 100 | read_batch 50000 1000 | read_formatted numpy 5000 | read_formatted pandas 5000 | read_formatted tensorflow 5000 | read_formatted torch 5000 | read_formatted_batch numpy 5000 10 | read_formatted_batch numpy 5000 1000 | shuffled read 5000 | shuffled read 50000 | shuffled read_batch 50000 10 | shuffled read_batch 50000 100 | shuffled read_batch 50000 1000 | shuffled read_formatted numpy 5000 | shuffled read_formatted_batch numpy 5000 10 | shuffled read_formatted_batch numpy 5000 1000 |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.295157 / 0.215209 (0.079948) | 2.910979 / 2.077655 (0.833324) | 1.575772 / 1.504120 (0.071652) | 1.456955 / 1.541195 (-0.084239) | 1.468982 / 1.468490 (0.000492) | 0.560309 / 4.584777 (-4.024468) | 2.460171 / 3.745712 (-1.285541) | 2.805713 / 5.269862 (-2.464149) | 1.754074 / 4.565676 (-2.811603) | 0.063333 / 0.424275 (-0.360942) | 0.004940 / 0.007607 (-0.002667) | 0.346141 / 0.226044 (0.120097) | 3.463431 / 2.268929 (1.194502) | 1.929135 / 55.444624 (-53.515490) | 1.660191 / 6.876477 (-5.216286) | 1.668327 / 2.142072 (-0.473746) | 0.644183 / 4.805227 (-4.161044) | 0.115738 / 6.500664 (-6.384926) | 0.041347 / 0.075469 (-0.034122) |

### Benchmark: benchmark_map_filter.json

| metric | filter | map fast-tokenizer batched | map identity | map identity batched | map no-op batched | map no-op batched numpy | map no-op batched pandas | map no-op batched pytorch | map no-op batched tensorflow |
|--------|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.961565 / 1.841788 (-0.880222) | 12.232589 / 8.074308 (4.158281) | 10.778774 / 10.191392 (0.587382) | 0.132709 / 0.680424 (-0.547715) | 0.015964 / 0.534201 (-0.518237) | 0.286944 / 0.579283 (-0.292340) | 0.279740 / 0.434364 (-0.154624) | 0.333024 / 0.540337 (-0.207314) | 0.438819 / 1.386936 (-0.948117) |

</details>
</details>

![](https://cml.dev/watermark.png#51002cb0325772adaf46d6f3ce01d41c01b51079 "CML watermark")


The docs for this PR live [here](https://moon-ci-docs.huggingface.co/docs/datasets/pr_6458). All of your documentation changes will be reflected on that endpoint.

<details>
<summary>Show benchmarks</summary>

PyArrow==8.0.0

<details>
<summary>Show updated benchmarks!</summary>

### Benchmark: benchmark_array_xd.json

| metric | read_batch_formatted_as_numpy after write_array2d | read_batch_formatted_as_numpy after write_flattened_sequence | read_batch_formatted_as_numpy after write_nested_sequence | read_batch_unformated after write_array2d | read_batch_unformated after write_flattened_sequence | read_batch_unformated after write_nested_sequence | read_col_formatted_as_numpy after write_array2d | read_col_formatted_as_numpy after write_flattened_sequence | read_col_formatted_as_numpy after write_nested_sequence | read_col_unformated after write_array2d | read_col_unformated after write_flattened_sequence | read_col_unformated after write_nested_sequence | read_formatted_as_numpy after write_array2d | read_formatted_as_numpy after write_flattened_sequence | read_formatted_as_numpy after write_nested_sequence | read_unformated after write_array2d | read_unformated after write_flattened_sequence | read_unformated after write_nested_sequence | write_array2d | write_flattened_sequence | write_nested_sequence |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.005317 / 0.011353 (-0.006036) | 0.003936 / 0.011008 (-0.007072) | 0.063122 / 0.038508 (0.024614) | 0.061274 / 0.023109 (0.038165) | 0.251764 / 0.275898 (-0.024134) | 0.274849 / 0.323480 (-0.048631) | 0.004059 / 0.007986 (-0.003927) | 0.002874 / 0.004328 (-0.001455) | 0.048716 / 0.004250 (0.044465) | 0.038281 / 0.037052 (0.001228) | 0.265224 / 0.258489 (0.006735) | 0.285962 / 0.293841 (-0.007878) | 0.028522 / 0.128546 (-0.100024) | 0.011150 / 0.075646 (-0.064496) | 0.208362 / 0.419271 (-0.210910) | 0.038900 / 0.043533 (-0.004633) | 0.254113 / 0.255139 (-0.001026) | 0.276721 / 0.283200 (-0.006478) | 0.018372 / 0.141683 (-0.123311) | 1.121336 / 1.452155 (-0.330818) | 1.189548 / 1.492716 (-0.303168) |

### Benchmark: benchmark_getitem\_100B.json

| metric | get_batch_of\_1024\_random_rows | get_batch_of\_1024\_rows | get_first_row | get_last_row |
|--------|---|---|---|---|
| new / old (diff) | 0.097633 / 0.018006 (0.079627) | 0.304443 / 0.000490 (0.303953) | 0.000218 / 0.000200 (0.000018) | 0.000054 / 0.000054 (-0.000001) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.021757 / 0.037411 (-0.015654) | 0.061978 / 0.014526 (0.047453) | 0.076296 / 0.176557 (-0.100260) | 0.122320 / 0.737135 (-0.614816) | 0.076738 / 0.296338 (-0.219601) |

### Benchmark: benchmark_iterating.json

| metric | read 5000 | read 50000 | read_batch 50000 10 | read_batch 50000 100 | read_batch 50000 1000 | read_formatted numpy 5000 | read_formatted pandas 5000 | read_formatted tensorflow 5000 | read_formatted torch 5000 | read_formatted_batch numpy 5000 10 | read_formatted_batch numpy 5000 1000 | shuffled read 5000 | shuffled read 50000 | shuffled read_batch 50000 10 | shuffled read_batch 50000 100 | shuffled read_batch 50000 1000 | shuffled read_formatted numpy 5000 | shuffled read_formatted_batch numpy 5000 10 | shuffled read_formatted_batch numpy 5000 1000 |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.284328 / 0.215209 (0.069119) | 2.793071 / 2.077655 (0.715417) | 1.504768 / 1.504120 (0.000648) | 1.386083 / 1.541195 (-0.155111) | 1.457593 / 1.468490 (-0.010897) | 0.575887 / 4.584777 (-4.008890) | 2.419396 / 3.745712 (-1.326316) | 2.931305 / 5.269862 (-2.338556) | 1.840759 / 4.565676 (-2.724917) | 0.063801 / 0.424275 (-0.360474) | 0.004966 / 0.007607 (-0.002641) | 0.341612 / 0.226044 (0.115568) | 3.402842 / 2.268929 (1.133913) | 1.860521 / 55.444624 (-53.584103) | 1.603156 / 6.876477 (-5.273321) | 1.665835 / 2.142072 (-0.476237) | 0.655299 / 4.805227 (-4.149929) | 0.124527 / 6.500664 (-6.376137) | 0.044021 / 0.075469 (-0.031449) |

### Benchmark: benchmark_map_filter.json

| metric | filter | map fast-tokenizer batched | map identity | map identity batched | map no-op batched | map no-op batched numpy | map no-op batched pandas | map no-op batched pytorch | map no-op batched tensorflow |
|--------|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.972068 / 1.841788 (-0.869720) | 12.393202 / 8.074308 (4.318894) | 10.420876 / 10.191392 (0.229484) | 0.140684 / 0.680424 (-0.539740) | 0.014442 / 0.534201 (-0.519759) | 0.288182 / 0.579283 (-0.291101) | 0.265029 / 0.434364 (-0.169334) | 0.327133 / 0.540337 (-0.213204) | 0.443403 / 1.386936 (-0.943533) |

</details>
PyArrow==latest

<details>
<summary>Show updated benchmarks!</summary>

### Benchmark: benchmark_array_xd.json

| metric | read_batch_formatted_as_numpy after write_array2d | read_batch_formatted_as_numpy after write_flattened_sequence | read_batch_formatted_as_numpy after write_nested_sequence | read_batch_unformated after write_array2d | read_batch_unformated after write_flattened_sequence | read_batch_unformated after write_nested_sequence | read_col_formatted_as_numpy after write_array2d | read_col_formatted_as_numpy after write_flattened_sequence | read_col_formatted_as_numpy after write_nested_sequence | read_col_unformated after write_array2d | read_col_unformated after write_flattened_sequence | read_col_unformated after write_nested_sequence | read_formatted_as_numpy after write_array2d | read_formatted_as_numpy after write_flattened_sequence | read_formatted_as_numpy after write_nested_sequence | read_unformated after write_array2d | read_unformated after write_flattened_sequence | read_unformated after write_nested_sequence | write_array2d | write_flattened_sequence | write_nested_sequence |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.005559 / 0.011353 (-0.005794) | 0.004046 / 0.011008 (-0.006962) | 0.048991 / 0.038508 (0.010483) | 0.059576 / 0.023109 (0.036467) | 0.273596 / 0.275898 (-0.002302) | 0.296658 / 0.323480 (-0.026822) | 0.004089 / 0.007986 (-0.003897) | 0.002777 / 0.004328 (-0.001551) | 0.048216 / 0.004250 (0.043966) | 0.043200 / 0.037052 (0.006148) | 0.276815 / 0.258489 (0.018326) | 0.300570 / 0.293841 (0.006729) | 0.030250 / 0.128546 (-0.098296) | 0.011322 / 0.075646 (-0.064324) | 0.057843 / 0.419271 (-0.361429) | 0.033366 / 0.043533 (-0.010167) | 0.275636 / 0.255139 (0.020497) | 0.293750 / 0.283200 (0.010550) | 0.018551 / 0.141683 (-0.123132) | 1.160919 / 1.452155 (-0.291236) | 1.214519 / 1.492716 (-0.278197) |

### Benchmark: benchmark_getitem\_100B.json

| metric | get_batch_of\_1024\_random_rows | get_batch_of\_1024\_rows | get_first_row | get_last_row |
|--------|---|---|---|---|
| new / old (diff) | 0.100074 / 0.018006 (0.082068) | 0.308434 / 0.000490 (0.307944) | 0.000232 / 0.000200 (0.000032) | 0.000044 / 0.000054 (-0.000010) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.022600 / 0.037411 (-0.014811) | 0.070506 / 0.014526 (0.055980) | 0.081185 / 0.176557 (-0.095371) | 0.120688 / 0.737135 (-0.616448) | 0.082897 / 0.296338 (-0.213441) |

### Benchmark: benchmark_iterating.json

| metric | read 5000 | read 50000 | read_batch 50000 10 | read_batch 50000 100 | read_batch 50000 1000 | read_formatted numpy 5000 | read_formatted pandas 5000 | read_formatted tensorflow 5000 | read_formatted torch 5000 | read_formatted_batch numpy 5000 10 | read_formatted_batch numpy 5000 1000 | shuffled read 5000 | shuffled read 50000 | shuffled read_batch 50000 10 | shuffled read_batch 50000 100 | shuffled read_batch 50000 1000 | shuffled read_formatted numpy 5000 | shuffled read_formatted_batch numpy 5000 10 | shuffled read_formatted_batch numpy 5000 1000 |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.306661 / 0.215209 (0.091452) | 2.989656 / 2.077655 (0.912001) | 1.618868 / 1.504120 (0.114749) | 1.485045 / 1.541195 (-0.056149) | 1.549359 / 1.468490 (0.080869) | 0.593596 / 4.584777 (-3.991181) | 2.466215 / 3.745712 (-1.279497) | 2.956570 / 5.269862 (-2.313292) | 1.823160 / 4.565676 (-2.742516) | 0.063442 / 0.424275 (-0.360833) | 0.004928 / 0.007607 (-0.002679) | 0.358464 / 0.226044 (0.132419) | 3.566345 / 2.268929 (1.297417) | 2.006784 / 55.444624 (-53.437840) | 1.687091 / 6.876477 (-5.189386) | 1.729464 / 2.142072 (-0.412609) | 0.655656 / 4.805227 (-4.149572) | 0.119044 / 6.500664 (-6.381620) | 0.042782 / 0.075469 (-0.032687) |

### Benchmark: benchmark_map_filter.json

| metric | filter | map fast-tokenizer batched | map identity | map identity batched | map no-op batched | map no-op batched numpy | map no-op batched pandas | map no-op batched pytorch | map no-op batched tensorflow |
|--------|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.974937 / 1.841788 (-0.866850) | 12.992888 / 8.074308 (4.918580) | 10.893713 / 10.191392 (0.702321) | 0.133853 / 0.680424 (-0.546570) | 0.016055 / 0.534201 (-0.518145) | 0.289342 / 0.579283 (-0.289941) | 0.286094 / 0.434364 (-0.148270) | 0.328670 / 0.540337 (-0.211667) | 0.444605 / 1.386936 (-0.942331) |

</details>
</details>

![](https://cml.dev/watermark.png#5a5bb38bcc71ea21f2d7304aab374fdb81ded463 "CML watermark")


<details>
<summary>Show benchmarks</summary>

PyArrow==8.0.0

<details>
<summary>Show updated benchmarks!</summary>

### Benchmark: benchmark_array_xd.json

| metric | read_batch_formatted_as_numpy after write_array2d | read_batch_formatted_as_numpy after write_flattened_sequence | read_batch_formatted_as_numpy after write_nested_sequence | read_batch_unformated after write_array2d | read_batch_unformated after write_flattened_sequence | read_batch_unformated after write_nested_sequence | read_col_formatted_as_numpy after write_array2d | read_col_formatted_as_numpy after write_flattened_sequence | read_col_formatted_as_numpy after write_nested_sequence | read_col_unformated after write_array2d | read_col_unformated after write_flattened_sequence | read_col_unformated after write_nested_sequence | read_formatted_as_numpy after write_array2d | read_formatted_as_numpy after write_flattened_sequence | read_formatted_as_numpy after write_nested_sequence | read_unformated after write_array2d | read_unformated after write_flattened_sequence | read_unformated after write_nested_sequence | write_array2d | write_flattened_sequence | write_nested_sequence |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.005705 / 0.011353 (-0.005648) | 0.003519 / 0.011008 (-0.007489) | 0.062009 / 0.038508 (0.023501) | 0.053481 / 0.023109 (0.030372) | 0.262669 / 0.275898 (-0.013229) | 0.280290 / 0.323480 (-0.043189) | 0.002957 / 0.007986 (-0.005029) | 0.002587 / 0.004328 (-0.001741) | 0.047876 / 0.004250 (0.043626) | 0.038868 / 0.037052 (0.001815) | 0.267854 / 0.258489 (0.009365) | 0.290430 / 0.293841 (-0.003411) | 0.028120 / 0.128546 (-0.100427) | 0.011042 / 0.075646 (-0.064605) | 0.206113 / 0.419271 (-0.213158) | 0.036039 / 0.043533 (-0.007494) | 0.257715 / 0.255139 (0.002576) | 0.281279 / 0.283200 (-0.001921) | 0.019790 / 0.141683 (-0.121893) | 1.114472 / 1.452155 (-0.337683) | 1.192219 / 1.492716 (-0.300497) |

### Benchmark: benchmark_getitem\_100B.json

| metric | get_batch_of\_1024\_random_rows | get_batch_of\_1024\_rows | get_first_row | get_last_row |
|--------|---|---|---|---|
| new / old (diff) | 0.091049 / 0.018006 (0.073043) | 0.300846 / 0.000490 (0.300356) | 0.000208 / 0.000200 (0.000008) | 0.000051 / 0.000054 (-0.000004) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.018569 / 0.037411 (-0.018843) | 0.060075 / 0.014526 (0.045549) | 0.073877 / 0.176557 (-0.102680) | 0.120337 / 0.737135 (-0.616799) | 0.075454 / 0.296338 (-0.220884) |

### Benchmark: benchmark_iterating.json

| metric | read 5000 | read 50000 | read_batch 50000 10 | read_batch 50000 100 | read_batch 50000 1000 | read_formatted numpy 5000 | read_formatted pandas 5000 | read_formatted tensorflow 5000 | read_formatted torch 5000 | read_formatted_batch numpy 5000 10 | read_formatted_batch numpy 5000 1000 | shuffled read 5000 | shuffled read 50000 | shuffled read_batch 50000 10 | shuffled read_batch 50000 100 | shuffled read_batch 50000 1000 | shuffled read_formatted numpy 5000 | shuffled read_formatted_batch numpy 5000 10 | shuffled read_formatted_batch numpy 5000 1000 |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.290084 / 0.215209 (0.074875) | 2.805712 / 2.077655 (0.728057) | 1.459393 / 1.504120 (-0.044727) | 1.327356 / 1.541195 (-0.213838) | 1.384734 / 1.468490 (-0.083756) | 0.574532 / 4.584777 (-4.010245) | 2.419696 / 3.745712 (-1.326016) | 2.805449 / 5.269862 (-2.464412) | 1.764127 / 4.565676 (-2.801549) | 0.063256 / 0.424275 (-0.361020) | 0.004954 / 0.007607 (-0.002653) | 0.344246 / 0.226044 (0.118202) | 3.396050 / 2.268929 (1.127121) | 1.807621 / 55.444624 (-53.637004) | 1.536627 / 6.876477 (-5.339850) | 1.552450 / 2.142072 (-0.589623) | 0.651156 / 4.805227 (-4.154071) | 0.119358 / 6.500664 (-6.381306) | 0.042810 / 0.075469 (-0.032660) |

### Benchmark: benchmark_map_filter.json

| metric | filter | map fast-tokenizer batched | map identity | map identity batched | map no-op batched | map no-op batched numpy | map no-op batched pandas | map no-op batched pytorch | map no-op batched tensorflow |
|--------|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.930646 / 1.841788 (-0.911142) | 11.830454 / 8.074308 (3.756146) | 10.615315 / 10.191392 (0.423923) | 0.130617 / 0.680424 (-0.549807) | 0.014081 / 0.534201 (-0.520120) | 0.285027 / 0.579283 (-0.294256) | 0.267296 / 0.434364 (-0.167068) | 0.331478 / 0.540337 (-0.208859) | 0.442676 / 1.386936 (-0.944260) |

</details>
PyArrow==latest

<details>
<summary>Show updated benchmarks!</summary>

### Benchmark: benchmark_array_xd.json

| metric | read_batch_formatted_as_numpy after write_array2d | read_batch_formatted_as_numpy after write_flattened_sequence | read_batch_formatted_as_numpy after write_nested_sequence | read_batch_unformated after write_array2d | read_batch_unformated after write_flattened_sequence | read_batch_unformated after write_nested_sequence | read_col_formatted_as_numpy after write_array2d | read_col_formatted_as_numpy after write_flattened_sequence | read_col_formatted_as_numpy after write_nested_sequence | read_col_unformated after write_array2d | read_col_unformated after write_flattened_sequence | read_col_unformated after write_nested_sequence | read_formatted_as_numpy after write_array2d | read_formatted_as_numpy after write_flattened_sequence | read_formatted_as_numpy after write_nested_sequence | read_unformated after write_array2d | read_unformated after write_flattened_sequence | read_unformated after write_nested_sequence | write_array2d | write_flattened_sequence | write_nested_sequence |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.005340 / 0.011353 (-0.006013) | 0.003745 / 0.011008 (-0.007264) | 0.049011 / 0.038508 (0.010503) | 0.051342 / 0.023109 (0.028233) | 0.272482 / 0.275898 (-0.003416) | 0.292816 / 0.323480 (-0.030663) | 0.003977 / 0.007986 (-0.004008) | 0.002642 / 0.004328 (-0.001687) | 0.048213 / 0.004250 (0.043963) | 0.040341 / 0.037052 (0.003289) | 0.275176 / 0.258489 (0.016687) | 0.301098 / 0.293841 (0.007257) | 0.029052 / 0.128546 (-0.099495) | 0.010796 / 0.075646 (-0.064850) | 0.057654 / 0.419271 (-0.361618) | 0.032914 / 0.043533 (-0.010619) | 0.271235 / 0.255139 (0.016096) | 0.289883 / 0.283200 (0.006684) | 0.018548 / 0.141683 (-0.123135) | 1.134072 / 1.452155 (-0.318083) | 1.208228 / 1.492716 (-0.284488) |

### Benchmark: benchmark_getitem\_100B.json

| metric | get_batch_of\_1024\_random_rows | get_batch_of\_1024\_rows | get_first_row | get_last_row |
|--------|---|---|---|---|
| new / old (diff) | 0.094524 / 0.018006 (0.076518) | 0.310162 / 0.000490 (0.309672) | 0.000237 / 0.000200 (0.000037) | 0.000057 / 0.000054 (0.000003) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.021090 / 0.037411 (-0.016321) | 0.068351 / 0.014526 (0.053825) | 0.082370 / 0.176557 (-0.094186) | 0.121648 / 0.737135 (-0.615487) | 0.083433 / 0.296338 (-0.212906) |

### Benchmark: benchmark_iterating.json

| metric | read 5000 | read 50000 | read_batch 50000 10 | read_batch 50000 100 | read_batch 50000 1000 | read_formatted numpy 5000 | read_formatted pandas 5000 | read_formatted tensorflow 5000 | read_formatted torch 5000 | read_formatted_batch numpy 5000 10 | read_formatted_batch numpy 5000 1000 | shuffled read 5000 | shuffled read 50000 | shuffled read_batch 50000 10 | shuffled read_batch 50000 100 | shuffled read_batch 50000 1000 | shuffled read_formatted numpy 5000 | shuffled read_formatted_batch numpy 5000 10 | shuffled read_formatted_batch numpy 5000 1000 |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.294616 / 0.215209 (0.079407) | 2.894194 / 2.077655 (0.816539) | 1.619739 / 1.504120 (0.115619) | 1.492466 / 1.541195 (-0.048729) | 1.511662 / 1.468490 (0.043172) | 0.557179 / 4.584777 (-4.027597) | 2.400669 / 3.745712 (-1.345043) | 2.781363 / 5.269862 (-2.488499) | 1.769144 / 4.565676 (-2.796533) | 0.063996 / 0.424275 (-0.360279) | 0.004922 / 0.007607 (-0.002685) | 0.354483 / 0.226044 (0.128438) | 3.474795 / 2.268929 (1.205867) | 1.985743 / 55.444624 (-53.458881) | 1.693173 / 6.876477 (-5.183303) | 1.695857 / 2.142072 (-0.446216) | 0.654800 / 4.805227 (-4.150427) | 0.117316 / 6.500664 (-6.383348) | 0.040708 / 0.075469 (-0.034761) |

### Benchmark: benchmark_map_filter.json

| metric | filter | map fast-tokenizer batched | map identity | map identity batched | map no-op batched | map no-op batched numpy | map no-op batched pandas | map no-op batched pytorch | map no-op batched tensorflow |
|--------|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.977678 / 1.841788 (-0.864109) | 12.214098 / 8.074308 (4.139790) | 10.741857 / 10.191392 (0.550465) | 0.130308 / 0.680424 (-0.550116) | 0.015053 / 0.534201 (-0.519148) | 0.295496 / 0.579283 (-0.283787) | 0.276348 / 0.434364 (-0.158015) | 0.326568 / 0.540337 (-0.213769) | 0.441902 / 1.386936 (-0.945034) |

</details>
</details>

![](https://cml.dev/watermark.png#214a3e6dcb66e9c1a8ff586553e8eee0f1c70710 "CML watermark")


<details>
<summary>Show benchmarks</summary>

PyArrow==8.0.0

<details>
<summary>Show updated benchmarks!</summary>

### Benchmark: benchmark_array_xd.json

| metric | read_batch_formatted_as_numpy after write_array2d | read_batch_formatted_as_numpy after write_flattened_sequence | read_batch_formatted_as_numpy after write_nested_sequence | read_batch_unformated after write_array2d | read_batch_unformated after write_flattened_sequence | read_batch_unformated after write_nested_sequence | read_col_formatted_as_numpy after write_array2d | read_col_formatted_as_numpy after write_flattened_sequence | read_col_formatted_as_numpy after write_nested_sequence | read_col_unformated after write_array2d | read_col_unformated after write_flattened_sequence | read_col_unformated after write_nested_sequence | read_formatted_as_numpy after write_array2d | read_formatted_as_numpy after write_flattened_sequence | read_formatted_as_numpy after write_nested_sequence | read_unformated after write_array2d | read_unformated after write_flattened_sequence | read_unformated after write_nested_sequence | write_array2d | write_flattened_sequence | write_nested_sequence |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.005218 / 0.011353 (-0.006135) | 0.003270 / 0.011008 (-0.007738) | 0.062380 / 0.038508 (0.023872) | 0.052896 / 0.023109 (0.029787) | 0.233060 / 0.275898 (-0.042838) | 0.259194 / 0.323480 (-0.064286) | 0.002880 / 0.007986 (-0.005106) | 0.002643 / 0.004328 (-0.001686) | 0.048084 / 0.004250 (0.043833) | 0.038807 / 0.037052 (0.001755) | 0.244925 / 0.258489 (-0.013564) | 0.269619 / 0.293841 (-0.024222) | 0.026901 / 0.128546 (-0.101646) | 0.010150 / 0.075646 (-0.065497) | 0.206854 / 0.419271 (-0.212417) | 0.035618 / 0.043533 (-0.007915) | 0.239577 / 0.255139 (-0.015562) | 0.259684 / 0.283200 (-0.023516) | 0.019823 / 0.141683 (-0.121860) | 1.074472 / 1.452155 (-0.377682) | 1.142911 / 1.492716 (-0.349805) |

### Benchmark: benchmark_getitem\_100B.json

| metric | get_batch_of\_1024\_random_rows | get_batch_of\_1024\_rows | get_first_row | get_last_row |
|--------|---|---|---|---|
| new / old (diff) | 0.092616 / 0.018006 (0.074610) | 0.301974 / 0.000490 (0.301485) | 0.000201 / 0.000200 (0.000002) | 0.000048 / 0.000054 (-0.000007) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.018864 / 0.037411 (-0.018548) | 0.061007 / 0.014526 (0.046481) | 0.073228 / 0.176557 (-0.103328) | 0.120719 / 0.737135 (-0.616416) | 0.075686 / 0.296338 (-0.220653) |

### Benchmark: benchmark_iterating.json

| metric | read 5000 | read 50000 | read_batch 50000 10 | read_batch 50000 100 | read_batch 50000 1000 | read_formatted numpy 5000 | read_formatted pandas 5000 | read_formatted tensorflow 5000 | read_formatted torch 5000 | read_formatted_batch numpy 5000 10 | read_formatted_batch numpy 5000 1000 | shuffled read 5000 | shuffled read 50000 | shuffled read_batch 50000 10 | shuffled read_batch 50000 100 | shuffled read_batch 50000 1000 | shuffled read_formatted numpy 5000 | shuffled read_formatted_batch numpy 5000 10 | shuffled read_formatted_batch numpy 5000 1000 |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.281404 / 0.215209 (0.066195) | 2.777671 / 2.077655 (0.700017) | 1.464689 / 1.504120 (-0.039431) | 1.345357 / 1.541195 (-0.195838) | 1.384273 / 1.468490 (-0.084217) | 0.560298 / 4.584777 (-4.024479) | 2.389877 / 3.745712 (-1.355835) | 2.755564 / 5.269862 (-2.514297) | 1.737754 / 4.565676 (-2.827922) | 0.063025 / 0.424275 (-0.361251) | 0.004975 / 0.007607 (-0.002632) | 0.346741 / 0.226044 (0.120697) | 3.321918 / 2.268929 (1.052989) | 1.815700 / 55.444624 (-53.628924) | 1.547333 / 6.876477 (-5.329144) | 1.564809 / 2.142072 (-0.577263) | 0.638645 / 4.805227 (-4.166582) | 0.118157 / 6.500664 (-6.382507) | 0.041605 / 0.075469 (-0.033864) |

### Benchmark: benchmark_map_filter.json

| metric | filter | map fast-tokenizer batched | map identity | map identity batched | map no-op batched | map no-op batched numpy | map no-op batched pandas | map no-op batched pytorch | map no-op batched tensorflow |
|--------|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.942515 / 1.841788 (-0.899273) | 11.400386 / 8.074308 (3.326078) | 10.208763 / 10.191392 (0.017370) | 0.138144 / 0.680424 (-0.542280) | 0.014354 / 0.534201 (-0.519847) | 0.288289 / 0.579283 (-0.290994) | 0.265973 / 0.434364 (-0.168391) | 0.327703 / 0.540337 (-0.212634) | 0.435474 / 1.386936 (-0.951462) |

</details>
PyArrow==latest

<details>
<summary>Show updated benchmarks!</summary>

### Benchmark: benchmark_array_xd.json

| metric | read_batch_formatted_as_numpy after write_array2d | read_batch_formatted_as_numpy after write_flattened_sequence | read_batch_formatted_as_numpy after write_nested_sequence | read_batch_unformated after write_array2d | read_batch_unformated after write_flattened_sequence | read_batch_unformated after write_nested_sequence | read_col_formatted_as_numpy after write_array2d | read_col_formatted_as_numpy after write_flattened_sequence | read_col_formatted_as_numpy after write_nested_sequence | read_col_unformated after write_array2d | read_col_unformated after write_flattened_sequence | read_col_unformated after write_nested_sequence | read_formatted_as_numpy after write_array2d | read_formatted_as_numpy after write_flattened_sequence | read_formatted_as_numpy after write_nested_sequence | read_unformated after write_array2d | read_unformated after write_flattened_sequence | read_unformated after write_nested_sequence | write_array2d | write_flattened_sequence | write_nested_sequence |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.005163 / 0.011353 (-0.006190) | 0.003307 / 0.011008 (-0.007701) | 0.048885 / 0.038508 (0.010377) | 0.049044 / 0.023109 (0.025935) | 0.261408 / 0.275898 (-0.014490) | 0.284625 / 0.323480 (-0.038855) | 0.003970 / 0.007986 (-0.004015) | 0.002754 / 0.004328 (-0.001575) | 0.048271 / 0.004250 (0.044021) | 0.039849 / 0.037052 (0.002797) | 0.266898 / 0.258489 (0.008409) | 0.291445 / 0.293841 (-0.002396) | 0.028477 / 0.128546 (-0.100069) | 0.010656 / 0.075646 (-0.064990) | 0.057732 / 0.419271 (-0.361539) | 0.033298 / 0.043533 (-0.010235) | 0.297773 / 0.255139 (0.042634) | 0.281894 / 0.283200 (-0.001305) | 0.018595 / 0.141683 (-0.123088) | 1.168849 / 1.452155 (-0.283306) | 1.183493 / 1.492716 (-0.309224) |

### Benchmark: benchmark_getitem\_100B.json

| metric | get_batch_of\_1024\_random_rows | get_batch_of\_1024\_rows | get_first_row | get_last_row |
|--------|---|---|---|---|
| new / old (diff) | 0.092683 / 0.018006 (0.074677) | 0.300387 / 0.000490 (0.299897) | 0.000221 / 0.000200 (0.000021) | 0.000052 / 0.000054 (-0.000003) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.021356 / 0.037411 (-0.016055) | 0.068095 / 0.014526 (0.053569) | 0.079806 / 0.176557 (-0.096750) | 0.118965 / 0.737135 (-0.618170) | 0.082066 / 0.296338 (-0.214273) |

### Benchmark: benchmark_iterating.json

| metric | read 5000 | read 50000 | read_batch 50000 10 | read_batch 50000 100 | read_batch 50000 1000 | read_formatted numpy 5000 | read_formatted pandas 5000 | read_formatted tensorflow 5000 | read_formatted torch 5000 | read_formatted_batch numpy 5000 10 | read_formatted_batch numpy 5000 1000 | shuffled read 5000 | shuffled read 50000 | shuffled read_batch 50000 10 | shuffled read_batch 50000 100 | shuffled read_batch 50000 1000 | shuffled read_formatted numpy 5000 | shuffled read_formatted_batch numpy 5000 10 | shuffled read_formatted_batch numpy 5000 1000 |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.293105 / 0.215209 (0.077896) | 2.842800 / 2.077655 (0.765146) | 1.572052 / 1.504120 (0.067932) | 1.450156 / 1.541195 (-0.091038) | 1.464227 / 1.468490 (-0.004263) | 0.561215 / 4.584777 (-4.023562) | 2.456117 / 3.745712 (-1.289596) | 2.739766 / 5.269862 (-2.530095) | 1.730354 / 4.565676 (-2.835323) | 0.062636 / 0.424275 (-0.361639) | 0.004933 / 0.007607 (-0.002674) | 0.345800 / 0.226044 (0.119756) | 3.415858 / 2.268929 (1.146929) | 1.937288 / 55.444624 (-53.507336) | 1.661975 / 6.876477 (-5.214502) | 1.660347 / 2.142072 (-0.481726) | 0.642780 / 4.805227 (-4.162448) | 0.116643 / 6.500664 (-6.384021) | 0.041282 / 0.075469 (-0.034187) |

### Benchmark: benchmark_map_filter.json

| metric | filter | map fast-tokenizer batched | map identity | map identity batched | map no-op batched | map no-op batched numpy | map no-op batched pandas | map no-op batched pytorch | map no-op batched tensorflow |
|--------|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.976629 / 1.841788 (-0.865159) | 11.900319 / 8.074308 (3.826011) | 10.574198 / 10.191392 (0.382806) | 0.129689 / 0.680424 (-0.550735) | 0.015390 / 0.534201 (-0.518811) | 0.286543 / 0.579283 (-0.292741) | 0.277676 / 0.434364 (-0.156688) | 0.325053 / 0.540337 (-0.215284) | 0.439663 / 1.386936 (-0.947274) |

</details>
</details>

![](https://cml.dev/watermark.png#b7a9674e17156ff10124632ba705125288de7442 "CML watermark")


<details>
<summary>Show benchmarks</summary>

PyArrow==8.0.0

<details>
<summary>Show updated benchmarks!</summary>

### Benchmark: benchmark_array_xd.json

| metric | read_batch_formatted_as_numpy after write_array2d | read_batch_formatted_as_numpy after write_flattened_sequence | read_batch_formatted_as_numpy after write_nested_sequence | read_batch_unformated after write_array2d | read_batch_unformated after write_flattened_sequence | read_batch_unformated after write_nested_sequence | read_col_formatted_as_numpy after write_array2d | read_col_formatted_as_numpy after write_flattened_sequence | read_col_formatted_as_numpy after write_nested_sequence | read_col_unformated after write_array2d | read_col_unformated after write_flattened_sequence | read_col_unformated after write_nested_sequence | read_formatted_as_numpy after write_array2d | read_formatted_as_numpy after write_flattened_sequence | read_formatted_as_numpy after write_nested_sequence | read_unformated after write_array2d | read_unformated after write_flattened_sequence | read_unformated after write_nested_sequence | write_array2d | write_flattened_sequence | write_nested_sequence |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.005382 / 0.011353 (-0.005971) | 0.003606 / 0.011008 (-0.007402) | 0.063234 / 0.038508 (0.024726) | 0.053738 / 0.023109 (0.030629) | 0.250405 / 0.275898 (-0.025493) | 0.272244 / 0.323480 (-0.051236) | 0.002896 / 0.007986 (-0.005090) | 0.002684 / 0.004328 (-0.001644) | 0.048394 / 0.004250 (0.044143) | 0.039017 / 0.037052 (0.001964) | 0.259554 / 0.258489 (0.001065) | 0.287215 / 0.293841 (-0.006626) | 0.028290 / 0.128546 (-0.100257) | 0.011482 / 0.075646 (-0.064164) | 0.214264 / 0.419271 (-0.205007) | 0.036257 / 0.043533 (-0.007276) | 0.252873 / 0.255139 (-0.002266) | 0.271269 / 0.283200 (-0.011931) | 0.017173 / 0.141683 (-0.124510) | 1.137474 / 1.452155 (-0.314681) | 1.161499 / 1.492716 (-0.331217) |

### Benchmark: benchmark_getitem\_100B.json

| metric | get_batch_of\_1024\_random_rows | get_batch_of\_1024\_rows | get_first_row | get_last_row |
|--------|---|---|---|---|
| new / old (diff) | 0.092424 / 0.018006 (0.074418) | 0.283703 / 0.000490 (0.283213) | 0.000209 / 0.000200 (0.000009) | 0.000044 / 0.000054 (-0.000010) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.018307 / 0.037411 (-0.019105) | 0.060780 / 0.014526 (0.046254) | 0.073984 / 0.176557 (-0.102573) | 0.120824 / 0.737135 (-0.616311) | 0.074724 / 0.296338 (-0.221615) |

### Benchmark: benchmark_iterating.json

| metric | read 5000 | read 50000 | read_batch 50000 10 | read_batch 50000 100 | read_batch 50000 1000 | read_formatted numpy 5000 | read_formatted pandas 5000 | read_formatted tensorflow 5000 | read_formatted torch 5000 | read_formatted_batch numpy 5000 10 | read_formatted_batch numpy 5000 1000 | shuffled read 5000 | shuffled read 50000 | shuffled read_batch 50000 10 | shuffled read_batch 50000 100 | shuffled read_batch 50000 1000 | shuffled read_formatted numpy 5000 | shuffled read_formatted_batch numpy 5000 10 | shuffled read_formatted_batch numpy 5000 1000 |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.297682 / 0.215209 (0.082473) | 2.853267 / 2.077655 (0.775612) | 1.567643 / 1.504120 (0.063523) | 1.437218 / 1.541195 (-0.103976) | 1.467187 / 1.468490 (-0.001304) | 0.560552 / 4.584777 (-4.024225) | 2.387848 / 3.745712 (-1.357864) | 2.718946 / 5.269862 (-2.550916) | 1.724107 / 4.565676 (-2.841570) | 0.061923 / 0.424275 (-0.362352) | 0.004828 / 0.007607 (-0.002779) | 0.353916 / 0.226044 (0.127871) | 3.404477 / 2.268929 (1.135548) | 1.906078 / 55.444624 (-53.538546) | 1.629686 / 6.876477 (-5.246791) | 1.640839 / 2.142072 (-0.501233) | 0.641082 / 4.805227 (-4.164145) | 0.118078 / 6.500664 (-6.382586) | 0.041881 / 0.075469 (-0.033588) |

### Benchmark: benchmark_map_filter.json

| metric | filter | map fast-tokenizer batched | map identity | map identity batched | map no-op batched | map no-op batched numpy | map no-op batched pandas | map no-op batched pytorch | map no-op batched tensorflow |
|--------|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.936062 / 1.841788 (-0.905726) | 11.397678 / 8.074308 (3.323370) | 10.385159 / 10.191392 (0.193766) | 0.127337 / 0.680424 (-0.553087) | 0.013562 / 0.534201 (-0.520639) | 0.290817 / 0.579283 (-0.288466) | 0.259377 / 0.434364 (-0.174987) | 0.324829 / 0.540337 (-0.215508) | 0.434344 / 1.386936 (-0.952592) |

</details>
PyArrow==latest

<details>
<summary>Show updated benchmarks!</summary>

### Benchmark: benchmark_array_xd.json

| metric | read_batch_formatted_as_numpy after write_array2d | read_batch_formatted_as_numpy after write_flattened_sequence | read_batch_formatted_as_numpy after write_nested_sequence | read_batch_unformated after write_array2d | read_batch_unformated after write_flattened_sequence | read_batch_unformated after write_nested_sequence | read_col_formatted_as_numpy after write_array2d | read_col_formatted_as_numpy after write_flattened_sequence | read_col_formatted_as_numpy after write_nested_sequence | read_col_unformated after write_array2d | read_col_unformated after write_flattened_sequence | read_col_unformated after write_nested_sequence | read_formatted_as_numpy after write_array2d | read_formatted_as_numpy after write_flattened_sequence | read_formatted_as_numpy after write_nested_sequence | read_unformated after write_array2d | read_unformated after write_flattened_sequence | read_unformated after write_nested_sequence | write_array2d | write_flattened_sequence | write_nested_sequence |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.005134 / 0.011353 (-0.006219) | 0.003404 / 0.011008 (-0.007604) | 0.048281 / 0.038508 (0.009772) | 0.050952 / 0.023109 (0.027842) | 0.277553 / 0.275898 (0.001655) | 0.298855 / 0.323480 (-0.024625) | 0.003928 / 0.007986 (-0.004058) | 0.002642 / 0.004328 (-0.001687) | 0.047374 / 0.004250 (0.043123) | 0.039883 / 0.037052 (0.002831) | 0.279808 / 0.258489 (0.021318) | 0.301604 / 0.293841 (0.007763) | 0.028708 / 0.128546 (-0.099838) | 0.010949 / 0.075646 (-0.064697) | 0.057090 / 0.419271 (-0.362181) | 0.032438 / 0.043533 (-0.011095) | 0.274690 / 0.255139 (0.019551) | 0.290912 / 0.283200 (0.007712) | 0.017556 / 0.141683 (-0.124127) | 1.111091 / 1.452155 (-0.341064) | 1.166063 / 1.492716 (-0.326653) |

### Benchmark: benchmark_getitem\_100B.json

| metric | get_batch_of\_1024\_random_rows | get_batch_of\_1024\_rows | get_first_row | get_last_row |
|--------|---|---|---|---|
| new / old (diff) | 0.090557 / 0.018006 (0.072551) | 0.298661 / 0.000490 (0.298171) | 0.000228 / 0.000200 (0.000028) | 0.000045 / 0.000054 (-0.000009) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.021712 / 0.037411 (-0.015699) | 0.068682 / 0.014526 (0.054156) | 0.080108 / 0.176557 (-0.096449) | 0.119480 / 0.737135 (-0.617655) | 0.082703 / 0.296338 (-0.213636) |

### Benchmark: benchmark_iterating.json

| metric | read 5000 | read 50000 | read_batch 50000 10 | read_batch 50000 100 | read_batch 50000 1000 | read_formatted numpy 5000 | read_formatted pandas 5000 | read_formatted tensorflow 5000 | read_formatted torch 5000 | read_formatted_batch numpy 5000 10 | read_formatted_batch numpy 5000 1000 | shuffled read 5000 | shuffled read 50000 | shuffled read_batch 50000 10 | shuffled read_batch 50000 100 | shuffled read_batch 50000 1000 | shuffled read_formatted numpy 5000 | shuffled read_formatted_batch numpy 5000 10 | shuffled read_formatted_batch numpy 5000 1000 |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.294095 / 0.215209 (0.078886) | 2.884758 / 2.077655 (0.807103) | 1.598312 / 1.504120 (0.094192) | 1.480050 / 1.541195 (-0.061145) | 1.488611 / 1.468490 (0.020121) | 0.556052 / 4.584777 (-4.028724) | 2.435484 / 3.745712 (-1.310228) | 2.741592 / 5.269862 (-2.528270) | 1.706223 / 4.565676 (-2.859454) | 0.062214 / 0.424275 (-0.362061) | 0.004901 / 0.007607 (-0.002706) | 0.346301 / 0.226044 (0.120257) | 3.474516 / 2.268929 (1.205587) | 1.995205 / 55.444624 (-53.449419) | 1.726349 / 6.876477 (-5.150128) | 1.659600 / 2.142072 (-0.482472) | 0.643560 / 4.805227 (-4.161667) | 0.115222 / 6.500664 (-6.385442) | 0.041137 / 0.075469 (-0.034332) |

### Benchmark: benchmark_map_filter.json

| metric | filter | map fast-tokenizer batched | map identity | map identity batched | map no-op batched | map no-op batched numpy | map no-op batched pandas | map no-op batched pytorch | map no-op batched tensorflow |
|--------|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.974566 / 1.841788 (-0.867221) | 11.872479 / 8.074308 (3.798171) | 10.496919 / 10.191392 (0.305527) | 0.129087 / 0.680424 (-0.551337) | 0.014627 / 0.534201 (-0.519574) | 0.289070 / 0.579283 (-0.290213) | 0.269609 / 0.434364 (-0.164755) | 0.327785 / 0.540337 (-0.212553) | 0.444634 / 1.386936 (-0.942302) |

</details>
</details>

![](https://cml.dev/watermark.png#32e0960ea165a9481b1ff6eed31771475120cb38 "CML watermark")


<details>
<summary>Show benchmarks</summary>

PyArrow==8.0.0

<details>
<summary>Show updated benchmarks!</summary>

### Benchmark: benchmark_array_xd.json

| metric | read_batch_formatted_as_numpy after write_array2d | read_batch_formatted_as_numpy after write_flattened_sequence | read_batch_formatted_as_numpy after write_nested_sequence | read_batch_unformated after write_array2d | read_batch_unformated after write_flattened_sequence | read_batch_unformated after write_nested_sequence | read_col_formatted_as_numpy after write_array2d | read_col_formatted_as_numpy after write_flattened_sequence | read_col_formatted_as_numpy after write_nested_sequence | read_col_unformated after write_array2d | read_col_unformated after write_flattened_sequence | read_col_unformated after write_nested_sequence | read_formatted_as_numpy after write_array2d | read_formatted_as_numpy after write_flattened_sequence | read_formatted_as_numpy after write_nested_sequence | read_unformated after write_array2d | read_unformated after write_flattened_sequence | read_unformated after write_nested_sequence | write_array2d | write_flattened_sequence | write_nested_sequence |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.005080 / 0.011353 (-0.006273) | 0.003782 / 0.011008 (-0.007226) | 0.062816 / 0.038508 (0.024308) | 0.056338 / 0.023109 (0.033229) | 0.251317 / 0.275898 (-0.024581) | 0.269414 / 0.323480 (-0.054066) | 0.003984 / 0.007986 (-0.004001) | 0.002749 / 0.004328 (-0.001580) | 0.048126 / 0.004250 (0.043876) | 0.038516 / 0.037052 (0.001464) | 0.253809 / 0.258489 (-0.004680) | 0.283309 / 0.293841 (-0.010532) | 0.027015 / 0.128546 (-0.101531) | 0.010610 / 0.075646 (-0.065037) | 0.213024 / 0.419271 (-0.206247) | 0.035734 / 0.043533 (-0.007799) | 0.247909 / 0.255139 (-0.007230) | 0.263539 / 0.283200 (-0.019660) | 0.018408 / 0.141683 (-0.123275) | 1.104366 / 1.452155 (-0.347789) | 1.169668 / 1.492716 (-0.323048) |

### Benchmark: benchmark_getitem\_100B.json

| metric | get_batch_of\_1024\_random_rows | get_batch_of\_1024\_rows | get_first_row | get_last_row |
|--------|---|---|---|---|
| new / old (diff) | 0.114366 / 0.018006 (0.096360) | 0.317674 / 0.000490 (0.317184) | 0.000227 / 0.000200 (0.000027) | 0.000043 / 0.000054 (-0.000011) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.018955 / 0.037411 (-0.018457) | 0.060716 / 0.014526 (0.046190) | 0.072963 / 0.176557 (-0.103593) | 0.121671 / 0.737135 (-0.615464) | 0.073785 / 0.296338 (-0.222554) |

### Benchmark: benchmark_iterating.json

| metric | read 5000 | read 50000 | read_batch 50000 10 | read_batch 50000 100 | read_batch 50000 1000 | read_formatted numpy 5000 | read_formatted pandas 5000 | read_formatted tensorflow 5000 | read_formatted torch 5000 | read_formatted_batch numpy 5000 10 | read_formatted_batch numpy 5000 1000 | shuffled read 5000 | shuffled read 50000 | shuffled read_batch 50000 10 | shuffled read_batch 50000 100 | shuffled read_batch 50000 1000 | shuffled read_formatted numpy 5000 | shuffled read_formatted_batch numpy 5000 10 | shuffled read_formatted_batch numpy 5000 1000 |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.292349 / 0.215209 (0.077140) | 2.832049 / 2.077655 (0.754394) | 1.504488 / 1.504120 (0.000368) | 1.403418 / 1.541195 (-0.137777) | 1.449223 / 1.468490 (-0.019267) | 0.563846 / 4.584777 (-4.020931) | 2.376726 / 3.745712 (-1.368986) | 2.823304 / 5.269862 (-2.446558) | 1.774858 / 4.565676 (-2.790818) | 0.063229 / 0.424275 (-0.361046) | 0.004923 / 0.007607 (-0.002684) | 0.347240 / 0.226044 (0.121195) | 3.486563 / 2.268929 (1.217634) | 1.890516 / 55.444624 (-53.554109) | 1.570620 / 6.876477 (-5.305857) | 1.600842 / 2.142072 (-0.541231) | 0.644287 / 4.805227 (-4.160940) | 0.116931 / 6.500664 (-6.383733) | 0.042068 / 0.075469 (-0.033401) |

### Benchmark: benchmark_map_filter.json

| metric | filter | map fast-tokenizer batched | map identity | map identity batched | map no-op batched | map no-op batched numpy | map no-op batched pandas | map no-op batched pytorch | map no-op batched tensorflow |
|--------|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.935662 / 1.841788 (-0.906126) | 11.950247 / 8.074308 (3.875939) | 10.636225 / 10.191392 (0.444833) | 0.139137 / 0.680424 (-0.541287) | 0.014473 / 0.534201 (-0.519728) | 0.294213 / 0.579283 (-0.285070) | 0.273413 / 0.434364 (-0.160951) | 0.325930 / 0.540337 (-0.214407) | 0.444265 / 1.386936 (-0.942671) |

</details>
PyArrow==latest

<details>
<summary>Show updated benchmarks!</summary>

### Benchmark: benchmark_array_xd.json

| metric | read_batch_formatted_as_numpy after write_array2d | read_batch_formatted_as_numpy after write_flattened_sequence | read_batch_formatted_as_numpy after write_nested_sequence | read_batch_unformated after write_array2d | read_batch_unformated after write_flattened_sequence | read_batch_unformated after write_nested_sequence | read_col_formatted_as_numpy after write_array2d | read_col_formatted_as_numpy after write_flattened_sequence | read_col_formatted_as_numpy after write_nested_sequence | read_col_unformated after write_array2d | read_col_unformated after write_flattened_sequence | read_col_unformated after write_nested_sequence | read_formatted_as_numpy after write_array2d | read_formatted_as_numpy after write_flattened_sequence | read_formatted_as_numpy after write_nested_sequence | read_unformated after write_array2d | read_unformated after write_flattened_sequence | read_unformated after write_nested_sequence | write_array2d | write_flattened_sequence | write_nested_sequence |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.005448 / 0.011353 (-0.005904) | 0.003155 / 0.011008 (-0.007853) | 0.048626 / 0.038508 (0.010117) | 0.057427 / 0.023109 (0.034318) | 0.270412 / 0.275898 (-0.005486) | 0.290816 / 0.323480 (-0.032664) | 0.004744 / 0.007986 (-0.003241) | 0.002776 / 0.004328 (-0.001552) | 0.047953 / 0.004250 (0.043703) | 0.041126 / 0.037052 (0.004073) | 0.276046 / 0.258489 (0.017557) | 0.297548 / 0.293841 (0.003707) | 0.029308 / 0.128546 (-0.099238) | 0.010516 / 0.075646 (-0.065131) | 0.056982 / 0.419271 (-0.362290) | 0.032922 / 0.043533 (-0.010611) | 0.271342 / 0.255139 (0.016203) | 0.288963 / 0.283200 (0.005763) | 0.019048 / 0.141683 (-0.122635) | 1.130453 / 1.452155 (-0.321702) | 1.206462 / 1.492716 (-0.286254) |

### Benchmark: benchmark_getitem\_100B.json

| metric | get_batch_of\_1024\_random_rows | get_batch_of\_1024\_rows | get_first_row | get_last_row |
|--------|---|---|---|---|
| new / old (diff) | 0.099249 / 0.018006 (0.081242) | 0.312409 / 0.000490 (0.311919) | 0.000224 / 0.000200 (0.000024) | 0.000044 / 0.000054 (-0.000011) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.021992 / 0.037411 (-0.015419) | 0.068377 / 0.014526 (0.053851) | 0.080749 / 0.176557 (-0.095807) | 0.120534 / 0.737135 (-0.616602) | 0.082549 / 0.296338 (-0.213790) |

### Benchmark: benchmark_iterating.json

| metric | read 5000 | read 50000 | read_batch 50000 10 | read_batch 50000 100 | read_batch 50000 1000 | read_formatted numpy 5000 | read_formatted pandas 5000 | read_formatted tensorflow 5000 | read_formatted torch 5000 | read_formatted_batch numpy 5000 10 | read_formatted_batch numpy 5000 1000 | shuffled read 5000 | shuffled read 50000 | shuffled read_batch 50000 10 | shuffled read_batch 50000 100 | shuffled read_batch 50000 1000 | shuffled read_formatted numpy 5000 | shuffled read_formatted_batch numpy 5000 10 | shuffled read_formatted_batch numpy 5000 1000 |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.299634 / 0.215209 (0.084425) | 2.943496 / 2.077655 (0.865841) | 1.602842 / 1.504120 (0.098722) | 1.462140 / 1.541195 (-0.079055) | 1.511082 / 1.468490 (0.042592) | 0.574148 / 4.584777 (-4.010629) | 2.492158 / 3.745712 (-1.253554) | 2.921695 / 5.269862 (-2.348166) | 1.812416 / 4.565676 (-2.753260) | 0.064145 / 0.424275 (-0.360130) | 0.005133 / 0.007607 (-0.002475) | 0.357935 / 0.226044 (0.131891) | 3.543728 / 2.268929 (1.274800) | 1.948676 / 55.444624 (-53.495948) | 1.664960 / 6.876477 (-5.211517) | 1.678703 / 2.142072 (-0.463370) | 0.645867 / 4.805227 (-4.159360) | 0.117671 / 6.500664 (-6.382993) | 0.040887 / 0.075469 (-0.034582) |

### Benchmark: benchmark_map_filter.json

| metric | filter | map fast-tokenizer batched | map identity | map identity batched | map no-op batched | map no-op batched numpy | map no-op batched pandas | map no-op batched pytorch | map no-op batched tensorflow |
|--------|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.979127 / 1.841788 (-0.862661) | 12.363904 / 8.074308 (4.289596) | 10.673725 / 10.191392 (0.482333) | 0.143358 / 0.680424 (-0.537066) | 0.015375 / 0.534201 (-0.518825) | 0.287590 / 0.579283 (-0.291694) | 0.284742 / 0.434364 (-0.149622) | 0.326901 / 0.540337 (-0.213437) | 0.443962 / 1.386936 (-0.942974) |

</details>
</details>

![](https://cml.dev/watermark.png#68099ca55294bfc12a34781835dd73c533a764bd "CML watermark")


<details>
<summary>Show benchmarks</summary>

PyArrow==8.0.0

<details>
<summary>Show updated benchmarks!</summary>

### Benchmark: benchmark_array_xd.json

| metric | read_batch_formatted_as_numpy after write_array2d | read_batch_formatted_as_numpy after write_flattened_sequence | read_batch_formatted_as_numpy after write_nested_sequence | read_batch_unformated after write_array2d | read_batch_unformated after write_flattened_sequence | read_batch_unformated after write_nested_sequence | read_col_formatted_as_numpy after write_array2d | read_col_formatted_as_numpy after write_flattened_sequence | read_col_formatted_as_numpy after write_nested_sequence | read_col_unformated after write_array2d | read_col_unformated after write_flattened_sequence | read_col_unformated after write_nested_sequence | read_formatted_as_numpy after write_array2d | read_formatted_as_numpy after write_flattened_sequence | read_formatted_as_numpy after write_nested_sequence | read_unformated after write_array2d | read_unformated after write_flattened_sequence | read_unformated after write_nested_sequence | write_array2d | write_flattened_sequence | write_nested_sequence |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.004994 / 0.011353 (-0.006359) | 0.003368 / 0.011008 (-0.007640) | 0.062803 / 0.038508 (0.024295) | 0.050778 / 0.023109 (0.027669) | 0.255955 / 0.275898 (-0.019943) | 0.278215 / 0.323480 (-0.045265) | 0.003801 / 0.007986 (-0.004184) | 0.002703 / 0.004328 (-0.001626) | 0.048369 / 0.004250 (0.044119) | 0.037795 / 0.037052 (0.000743) | 0.255634 / 0.258489 (-0.002855) | 0.284226 / 0.293841 (-0.009615) | 0.027252 / 0.128546 (-0.101294) | 0.010686 / 0.075646 (-0.064961) | 0.206139 / 0.419271 (-0.213133) | 0.035543 / 0.043533 (-0.007990) | 0.257167 / 0.255139 (0.002028) | 0.277784 / 0.283200 (-0.005416) | 0.016938 / 0.141683 (-0.124745) | 1.108595 / 1.452155 (-0.343560) | 1.188542 / 1.492716 (-0.304175) |

### Benchmark: benchmark_getitem\_100B.json

| metric | get_batch_of\_1024\_random_rows | get_batch_of\_1024\_rows | get_first_row | get_last_row |
|--------|---|---|---|---|
| new / old (diff) | 0.090938 / 0.018006 (0.072932) | 0.298463 / 0.000490 (0.297973) | 0.000203 / 0.000200 (0.000003) | 0.000048 / 0.000054 (-0.000006) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.027762 / 0.037411 (-0.009649) | 0.060539 / 0.014526 (0.046014) | 0.075986 / 0.176557 (-0.100570) | 0.133851 / 0.737135 (-0.603285) | 0.074669 / 0.296338 (-0.221670) |

### Benchmark: benchmark_iterating.json

| metric | read 5000 | read 50000 | read_batch 50000 10 | read_batch 50000 100 | read_batch 50000 1000 | read_formatted numpy 5000 | read_formatted pandas 5000 | read_formatted tensorflow 5000 | read_formatted torch 5000 | read_formatted_batch numpy 5000 10 | read_formatted_batch numpy 5000 1000 | shuffled read 5000 | shuffled read 50000 | shuffled read_batch 50000 10 | shuffled read_batch 50000 100 | shuffled read_batch 50000 1000 | shuffled read_formatted numpy 5000 | shuffled read_formatted_batch numpy 5000 10 | shuffled read_formatted_batch numpy 5000 1000 |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.285614 / 0.215209 (0.070405) | 2.810529 / 2.077655 (0.732874) | 1.537092 / 1.504120 (0.032973) | 1.412211 / 1.541195 (-0.128983) | 1.446395 / 1.468490 (-0.022095) | 0.559008 / 4.584777 (-4.025769) | 2.343445 / 3.745712 (-1.402267) | 2.748113 / 5.269862 (-2.521748) | 1.733593 / 4.565676 (-2.832083) | 0.061720 / 0.424275 (-0.362555) | 0.004930 / 0.007607 (-0.002677) | 0.330646 / 0.226044 (0.104602) | 3.314999 / 2.268929 (1.046071) | 1.854527 / 55.444624 (-53.590098) | 1.605819 / 6.876477 (-5.270657) | 1.591406 / 2.142072 (-0.550667) | 0.624239 / 4.805227 (-4.180988) | 0.115352 / 6.500664 (-6.385312) | 0.041600 / 0.075469 (-0.033869) |

### Benchmark: benchmark_map_filter.json

| metric | filter | map fast-tokenizer batched | map identity | map identity batched | map no-op batched | map no-op batched numpy | map no-op batched pandas | map no-op batched pytorch | map no-op batched tensorflow |
|--------|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.933179 / 1.841788 (-0.908608) | 11.456372 / 8.074308 (3.382064) | 10.578042 / 10.191392 (0.386650) | 0.128045 / 0.680424 (-0.552379) | 0.014212 / 0.534201 (-0.519989) | 0.284795 / 0.579283 (-0.294488) | 0.266210 / 0.434364 (-0.168153) | 0.344468 / 0.540337 (-0.195869) | 0.434414 / 1.386936 (-0.952522) |

</details>
PyArrow==latest

<details>
<summary>Show updated benchmarks!</summary>

### Benchmark: benchmark_array_xd.json

| metric | read_batch_formatted_as_numpy after write_array2d | read_batch_formatted_as_numpy after write_flattened_sequence | read_batch_formatted_as_numpy after write_nested_sequence | read_batch_unformated after write_array2d | read_batch_unformated after write_flattened_sequence | read_batch_unformated after write_nested_sequence | read_col_formatted_as_numpy after write_array2d | read_col_formatted_as_numpy after write_flattened_sequence | read_col_formatted_as_numpy after write_nested_sequence | read_col_unformated after write_array2d | read_col_unformated after write_flattened_sequence | read_col_unformated after write_nested_sequence | read_formatted_as_numpy after write_array2d | read_formatted_as_numpy after write_flattened_sequence | read_formatted_as_numpy after write_nested_sequence | read_unformated after write_array2d | read_unformated after write_flattened_sequence | read_unformated after write_nested_sequence | write_array2d | write_flattened_sequence | write_nested_sequence |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.005142 / 0.011353 (-0.006211) | 0.003607 / 0.011008 (-0.007401) | 0.048770 / 0.038508 (0.010262) | 0.051147 / 0.023109 (0.028038) | 0.277329 / 0.275898 (0.001430) | 0.300863 / 0.323480 (-0.022617) | 0.004005 / 0.007986 (-0.003980) | 0.002624 / 0.004328 (-0.001705) | 0.047740 / 0.004250 (0.043489) | 0.040811 / 0.037052 (0.003759) | 0.280020 / 0.258489 (0.021531) | 0.303758 / 0.293841 (0.009918) | 0.028273 / 0.128546 (-0.100274) | 0.010379 / 0.075646 (-0.065267) | 0.057503 / 0.419271 (-0.361768) | 0.032717 / 0.043533 (-0.010816) | 0.277560 / 0.255139 (0.022421) | 0.300622 / 0.283200 (0.017422) | 0.018142 / 0.141683 (-0.123541) | 1.121890 / 1.452155 (-0.330265) | 1.251481 / 1.492716 (-0.241235) |

### Benchmark: benchmark_getitem\_100B.json

| metric | get_batch_of\_1024\_random_rows | get_batch_of\_1024\_rows | get_first_row | get_last_row |
|--------|---|---|---|---|
| new / old (diff) | 0.091523 / 0.018006 (0.073517) | 0.300173 / 0.000490 (0.299683) | 0.000216 / 0.000200 (0.000016) | 0.000051 / 0.000054 (-0.000004) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.026386 / 0.037411 (-0.011025) | 0.078710 / 0.014526 (0.064184) | 0.090594 / 0.176557 (-0.085962) | 0.130623 / 0.737135 (-0.606512) | 0.092637 / 0.296338 (-0.203701) |

### Benchmark: benchmark_iterating.json

| metric | read 5000 | read 50000 | read_batch 50000 10 | read_batch 50000 100 | read_batch 50000 1000 | read_formatted numpy 5000 | read_formatted pandas 5000 | read_formatted tensorflow 5000 | read_formatted torch 5000 | read_formatted_batch numpy 5000 10 | read_formatted_batch numpy 5000 1000 | shuffled read 5000 | shuffled read 50000 | shuffled read_batch 50000 10 | shuffled read_batch 50000 100 | shuffled read_batch 50000 1000 | shuffled read_formatted numpy 5000 | shuffled read_formatted_batch numpy 5000 10 | shuffled read_formatted_batch numpy 5000 1000 |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.299427 / 0.215209 (0.084218) | 2.929463 / 2.077655 (0.851808) | 1.608905 / 1.504120 (0.104785) | 1.490863 / 1.541195 (-0.050331) | 1.484286 / 1.468490 (0.015796) | 0.568208 / 4.584777 (-4.016569) | 2.447081 / 3.745712 (-1.298632) | 2.801287 / 5.269862 (-2.468574) | 1.744449 / 4.565676 (-2.821227) | 0.064222 / 0.424275 (-0.360053) | 0.004959 / 0.007607 (-0.002648) | 0.350207 / 0.226044 (0.124162) | 3.471944 / 2.268929 (1.203016) | 1.951715 / 55.444624 (-53.492909) | 1.668764 / 6.876477 (-5.207713) | 1.675322 / 2.142072 (-0.466751) | 0.642217 / 4.805227 (-4.163011) | 0.116776 / 6.500664 (-6.383888) | 0.040812 / 0.075469 (-0.034658) |

### Benchmark: benchmark_map_filter.json

| metric | filter | map fast-tokenizer batched | map identity | map identity batched | map no-op batched | map no-op batched numpy | map no-op batched pandas | map no-op batched pytorch | map no-op batched tensorflow |
|--------|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.996478 / 1.841788 (-0.845310) | 12.090647 / 8.074308 (4.016339) | 10.723688 / 10.191392 (0.532296) | 0.141770 / 0.680424 (-0.538653) | 0.015578 / 0.534201 (-0.518623) | 0.288236 / 0.579283 (-0.291047) | 0.278542 / 0.434364 (-0.155822) | 0.327411 / 0.540337 (-0.212927) | 0.450309 / 1.386936 (-0.936627) |

</details>
</details>

![](https://cml.dev/watermark.png#5dd4698f483d37afe243db0ffae774cbd34a4af4 "CML watermark")


<details>
<summary>Show benchmarks</summary>

PyArrow==8.0.0

<details>
<summary>Show updated benchmarks!</summary>

### Benchmark: benchmark_array_xd.json

| metric | read_batch_formatted_as_numpy after write_array2d | read_batch_formatted_as_numpy after write_flattened_sequence | read_batch_formatted_as_numpy after write_nested_sequence | read_batch_unformated after write_array2d | read_batch_unformated after write_flattened_sequence | read_batch_unformated after write_nested_sequence | read_col_formatted_as_numpy after write_array2d | read_col_formatted_as_numpy after write_flattened_sequence | read_col_formatted_as_numpy after write_nested_sequence | read_col_unformated after write_array2d | read_col_unformated after write_flattened_sequence | read_col_unformated after write_nested_sequence | read_formatted_as_numpy after write_array2d | read_formatted_as_numpy after write_flattened_sequence | read_formatted_as_numpy after write_nested_sequence | read_unformated after write_array2d | read_unformated after write_flattened_sequence | read_unformated after write_nested_sequence | write_array2d | write_flattened_sequence | write_nested_sequence |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.004967 / 0.011353 (-0.006385) | 0.003382 / 0.011008 (-0.007627) | 0.063436 / 0.038508 (0.024928) | 0.050769 / 0.023109 (0.027659) | 0.254214 / 0.275898 (-0.021684) | 0.272076 / 0.323480 (-0.051404) | 0.003815 / 0.007986 (-0.004170) | 0.002618 / 0.004328 (-0.001711) | 0.049021 / 0.004250 (0.044771) | 0.037329 / 0.037052 (0.000277) | 0.261112 / 0.258489 (0.002623) | 0.284133 / 0.293841 (-0.009708) | 0.026828 / 0.128546 (-0.101719) | 0.010757 / 0.075646 (-0.064889) | 0.208047 / 0.419271 (-0.211225) | 0.035061 / 0.043533 (-0.008472) | 0.250896 / 0.255139 (-0.004243) | 0.273038 / 0.283200 (-0.010162) | 0.016559 / 0.141683 (-0.125124) | 1.128899 / 1.452155 (-0.323255) | 1.188857 / 1.492716 (-0.303860) |

### Benchmark: benchmark_getitem\_100B.json

| metric | get_batch_of\_1024\_random_rows | get_batch_of\_1024\_rows | get_first_row | get_last_row |
|--------|---|---|---|---|
| new / old (diff) | 0.100121 / 0.018006 (0.082114) | 0.298427 / 0.000490 (0.297937) | 0.000218 / 0.000200 (0.000018) | 0.000043 / 0.000054 (-0.000012) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.018369 / 0.037411 (-0.019042) | 0.060425 / 0.014526 (0.045899) | 0.073501 / 0.176557 (-0.103055) | 0.120254 / 0.737135 (-0.616881) | 0.074889 / 0.296338 (-0.221450) |

### Benchmark: benchmark_iterating.json

| metric | read 5000 | read 50000 | read_batch 50000 10 | read_batch 50000 100 | read_batch 50000 1000 | read_formatted numpy 5000 | read_formatted pandas 5000 | read_formatted tensorflow 5000 | read_formatted torch 5000 | read_formatted_batch numpy 5000 10 | read_formatted_batch numpy 5000 1000 | shuffled read 5000 | shuffled read 50000 | shuffled read_batch 50000 10 | shuffled read_batch 50000 100 | shuffled read_batch 50000 1000 | shuffled read_formatted numpy 5000 | shuffled read_formatted_batch numpy 5000 10 | shuffled read_formatted_batch numpy 5000 1000 |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.287153 / 0.215209 (0.071944) | 2.797036 / 2.077655 (0.719382) | 1.446216 / 1.504120 (-0.057904) | 1.336015 / 1.541195 (-0.205179) | 1.369841 / 1.468490 (-0.098650) | 0.559424 / 4.584777 (-4.025353) | 2.361344 / 3.745712 (-1.384368) | 2.766619 / 5.269862 (-2.503243) | 1.747235 / 4.565676 (-2.818441) | 0.066243 / 0.424275 (-0.358032) | 0.004974 / 0.007607 (-0.002633) | 0.333565 / 0.226044 (0.107520) | 3.319877 / 2.268929 (1.050948) | 1.798024 / 55.444624 (-53.646601) | 1.495896 / 6.876477 (-5.380580) | 1.529243 / 2.142072 (-0.612830) | 0.636609 / 4.805227 (-4.168618) | 0.116151 / 6.500664 (-6.384514) | 0.041779 / 0.075469 (-0.033690) |

### Benchmark: benchmark_map_filter.json

| metric | filter | map fast-tokenizer batched | map identity | map identity batched | map no-op batched | map no-op batched numpy | map no-op batched pandas | map no-op batched pytorch | map no-op batched tensorflow |
|--------|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.952176 / 1.841788 (-0.889611) | 11.559160 / 8.074308 (3.484852) | 10.556771 / 10.191392 (0.365379) | 0.127118 / 0.680424 (-0.553306) | 0.014142 / 0.534201 (-0.520059) | 0.286585 / 0.579283 (-0.292698) | 0.260233 / 0.434364 (-0.174131) | 0.324012 / 0.540337 (-0.216326) | 0.435131 / 1.386936 (-0.951805) |

</details>
PyArrow==latest

<details>
<summary>Show updated benchmarks!</summary>

### Benchmark: benchmark_array_xd.json

| metric | read_batch_formatted_as_numpy after write_array2d | read_batch_formatted_as_numpy after write_flattened_sequence | read_batch_formatted_as_numpy after write_nested_sequence | read_batch_unformated after write_array2d | read_batch_unformated after write_flattened_sequence | read_batch_unformated after write_nested_sequence | read_col_formatted_as_numpy after write_array2d | read_col_formatted_as_numpy after write_flattened_sequence | read_col_formatted_as_numpy after write_nested_sequence | read_col_unformated after write_array2d | read_col_unformated after write_flattened_sequence | read_col_unformated after write_nested_sequence | read_formatted_as_numpy after write_array2d | read_formatted_as_numpy after write_flattened_sequence | read_formatted_as_numpy after write_nested_sequence | read_unformated after write_array2d | read_unformated after write_flattened_sequence | read_unformated after write_nested_sequence | write_array2d | write_flattened_sequence | write_nested_sequence |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.005171 / 0.011353 (-0.006182) | 0.003402 / 0.011008 (-0.007607) | 0.048826 / 0.038508 (0.010318) | 0.050455 / 0.023109 (0.027346) | 0.272120 / 0.275898 (-0.003778) | 0.290404 / 0.323480 (-0.033076) | 0.003986 / 0.007986 (-0.003999) | 0.002569 / 0.004328 (-0.001760) | 0.047845 / 0.004250 (0.043595) | 0.040203 / 0.037052 (0.003150) | 0.278263 / 0.258489 (0.019774) | 0.299255 / 0.293841 (0.005414) | 0.028643 / 0.128546 (-0.099903) | 0.010584 / 0.075646 (-0.065062) | 0.056921 / 0.419271 (-0.362351) | 0.032362 / 0.043533 (-0.011171) | 0.274010 / 0.255139 (0.018871) | 0.288601 / 0.283200 (0.005401) | 0.017856 / 0.141683 (-0.123827) | 1.154112 / 1.452155 (-0.298043) | 1.216288 / 1.492716 (-0.276428) |

### Benchmark: benchmark_getitem\_100B.json

| metric | get_batch_of\_1024\_random_rows | get_batch_of\_1024\_rows | get_first_row | get_last_row |
|--------|---|---|---|---|
| new / old (diff) | 0.091399 / 0.018006 (0.073392) | 0.299966 / 0.000490 (0.299477) | 0.000218 / 0.000200 (0.000018) | 0.000054 / 0.000054 (-0.000000) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.021728 / 0.037411 (-0.015683) | 0.068285 / 0.014526 (0.053759) | 0.081767 / 0.176557 (-0.094789) | 0.120000 / 0.737135 (-0.617135) | 0.082149 / 0.296338 (-0.214189) |

### Benchmark: benchmark_iterating.json

| metric | read 5000 | read 50000 | read_batch 50000 10 | read_batch 50000 100 | read_batch 50000 1000 | read_formatted numpy 5000 | read_formatted pandas 5000 | read_formatted tensorflow 5000 | read_formatted torch 5000 | read_formatted_batch numpy 5000 10 | read_formatted_batch numpy 5000 1000 | shuffled read 5000 | shuffled read 50000 | shuffled read_batch 50000 10 | shuffled read_batch 50000 100 | shuffled read_batch 50000 1000 | shuffled read_formatted numpy 5000 | shuffled read_formatted_batch numpy 5000 10 | shuffled read_formatted_batch numpy 5000 1000 |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.289625 / 0.215209 (0.074416) | 2.835114 / 2.077655 (0.757460) | 1.583207 / 1.504120 (0.079087) | 1.465251 / 1.541195 (-0.075944) | 1.480691 / 1.468490 (0.012200) | 0.569103 / 4.584777 (-4.015674) | 2.416981 / 3.745712 (-1.328731) | 2.761746 / 5.269862 (-2.508115) | 1.720055 / 4.565676 (-2.845621) | 0.063349 / 0.424275 (-0.360926) | 0.004931 / 0.007607 (-0.002676) | 0.343658 / 0.226044 (0.117614) | 3.362996 / 2.268929 (1.094068) | 1.948088 / 55.444624 (-53.496536) | 1.659504 / 6.876477 (-5.216973) | 1.660359 / 2.142072 (-0.481713) | 0.647871 / 4.805227 (-4.157356) | 0.117395 / 6.500664 (-6.383269) | 0.041049 / 0.075469 (-0.034420) |

### Benchmark: benchmark_map_filter.json

| metric | filter | map fast-tokenizer batched | map identity | map identity batched | map no-op batched | map no-op batched numpy | map no-op batched pandas | map no-op batched pytorch | map no-op batched tensorflow |
|--------|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.953971 / 1.841788 (-0.887817) | 12.076998 / 8.074308 (4.002690) | 10.549021 / 10.191392 (0.357629) | 0.130026 / 0.680424 (-0.550398) | 0.015697 / 0.534201 (-0.518504) | 0.287125 / 0.579283 (-0.292158) | 0.298402 / 0.434364 (-0.135962) | 0.326005 / 0.540337 (-0.214332) | 0.444065 / 1.386936 (-0.942871) |

</details>
</details>

![](https://cml.dev/watermark.png#cf86d48792f585bf802bb2ff70e0d9c3a4de4bcf "CML watermark")


<details>
<summary>Show benchmarks</summary>

PyArrow==8.0.0

<details>
<summary>Show updated benchmarks!</summary>

### Benchmark: benchmark_array_xd.json

| metric | read_batch_formatted_as_numpy after write_array2d | read_batch_formatted_as_numpy after write_flattened_sequence | read_batch_formatted_as_numpy after write_nested_sequence | read_batch_unformated after write_array2d | read_batch_unformated after write_flattened_sequence | read_batch_unformated after write_nested_sequence | read_col_formatted_as_numpy after write_array2d | read_col_formatted_as_numpy after write_flattened_sequence | read_col_formatted_as_numpy after write_nested_sequence | read_col_unformated after write_array2d | read_col_unformated after write_flattened_sequence | read_col_unformated after write_nested_sequence | read_formatted_as_numpy after write_array2d | read_formatted_as_numpy after write_flattened_sequence | read_formatted_as_numpy after write_nested_sequence | read_unformated after write_array2d | read_unformated after write_flattened_sequence | read_unformated after write_nested_sequence | write_array2d | write_flattened_sequence | write_nested_sequence |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.005053 / 0.011353 (-0.006300) | 0.003537 / 0.011008 (-0.007472) | 0.062923 / 0.038508 (0.024415) | 0.053796 / 0.023109 (0.030687) | 0.242523 / 0.275898 (-0.033375) | 0.264014 / 0.323480 (-0.059466) | 0.002879 / 0.007986 (-0.005106) | 0.003273 / 0.004328 (-0.001055) | 0.048735 / 0.004250 (0.044484) | 0.037541 / 0.037052 (0.000488) | 0.248587 / 0.258489 (-0.009902) | 0.275531 / 0.293841 (-0.018310) | 0.027215 / 0.128546 (-0.101331) | 0.010466 / 0.075646 (-0.065180) | 0.206508 / 0.419271 (-0.212763) | 0.035606 / 0.043533 (-0.007927) | 0.251044 / 0.255139 (-0.004095) | 0.267183 / 0.283200 (-0.016016) | 0.018357 / 0.141683 (-0.123326) | 1.083513 / 1.452155 (-0.368642) | 1.152988 / 1.492716 (-0.339728) |

### Benchmark: benchmark_getitem\_100B.json

| metric | get_batch_of\_1024\_random_rows | get_batch_of\_1024\_rows | get_first_row | get_last_row |
|--------|---|---|---|---|
| new / old (diff) | 0.091749 / 0.018006 (0.073742) | 0.299946 / 0.000490 (0.299456) | 0.000212 / 0.000200 (0.000013) | 0.000042 / 0.000054 (-0.000013) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.018300 / 0.037411 (-0.019111) | 0.060691 / 0.014526 (0.046166) | 0.072998 / 0.176557 (-0.103559) | 0.120581 / 0.737135 (-0.616554) | 0.073912 / 0.296338 (-0.222427) |

### Benchmark: benchmark_iterating.json

| metric | read 5000 | read 50000 | read_batch 50000 10 | read_batch 50000 100 | read_batch 50000 1000 | read_formatted numpy 5000 | read_formatted pandas 5000 | read_formatted tensorflow 5000 | read_formatted torch 5000 | read_formatted_batch numpy 5000 10 | read_formatted_batch numpy 5000 1000 | shuffled read 5000 | shuffled read 50000 | shuffled read_batch 50000 10 | shuffled read_batch 50000 100 | shuffled read_batch 50000 1000 | shuffled read_formatted numpy 5000 | shuffled read_formatted_batch numpy 5000 10 | shuffled read_formatted_batch numpy 5000 1000 |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.277602 / 0.215209 (0.062393) | 2.719181 / 2.077655 (0.641526) | 1.450894 / 1.504120 (-0.053226) | 1.314344 / 1.541195 (-0.226851) | 1.351996 / 1.468490 (-0.116494) | 0.586231 / 4.584777 (-3.998546) | 2.349746 / 3.745712 (-1.395967) | 2.810060 / 5.269862 (-2.459802) | 1.761362 / 4.565676 (-2.804314) | 0.062535 / 0.424275 (-0.361740) | 0.004918 / 0.007607 (-0.002689) | 0.336091 / 0.226044 (0.110047) | 3.238139 / 2.268929 (0.969211) | 1.769734 / 55.444624 (-53.674890) | 1.505332 / 6.876477 (-5.371145) | 1.527875 / 2.142072 (-0.614198) | 0.640194 / 4.805227 (-4.165033) | 0.116567 / 6.500664 (-6.384097) | 0.042464 / 0.075469 (-0.033005) |

### Benchmark: benchmark_map_filter.json

| metric | filter | map fast-tokenizer batched | map identity | map identity batched | map no-op batched | map no-op batched numpy | map no-op batched pandas | map no-op batched pytorch | map no-op batched tensorflow |
|--------|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.930919 / 1.841788 (-0.910869) | 11.462498 / 8.074308 (3.388190) | 10.575359 / 10.191392 (0.383967) | 0.130567 / 0.680424 (-0.549857) | 0.014203 / 0.534201 (-0.519998) | 0.286944 / 0.579283 (-0.292339) | 0.264706 / 0.434364 (-0.169658) | 0.324820 / 0.540337 (-0.215517) | 0.434579 / 1.386936 (-0.952357) |

</details>
PyArrow==latest

<details>
<summary>Show updated benchmarks!</summary>

### Benchmark: benchmark_array_xd.json

| metric | read_batch_formatted_as_numpy after write_array2d | read_batch_formatted_as_numpy after write_flattened_sequence | read_batch_formatted_as_numpy after write_nested_sequence | read_batch_unformated after write_array2d | read_batch_unformated after write_flattened_sequence | read_batch_unformated after write_nested_sequence | read_col_formatted_as_numpy after write_array2d | read_col_formatted_as_numpy after write_flattened_sequence | read_col_formatted_as_numpy after write_nested_sequence | read_col_unformated after write_array2d | read_col_unformated after write_flattened_sequence | read_col_unformated after write_nested_sequence | read_formatted_as_numpy after write_array2d | read_formatted_as_numpy after write_flattened_sequence | read_formatted_as_numpy after write_nested_sequence | read_unformated after write_array2d | read_unformated after write_flattened_sequence | read_unformated after write_nested_sequence | write_array2d | write_flattened_sequence | write_nested_sequence |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.005164 / 0.011353 (-0.006189) | 0.003442 / 0.011008 (-0.007567) | 0.050146 / 0.038508 (0.011638) | 0.050800 / 0.023109 (0.027691) | 0.263405 / 0.275898 (-0.012493) | 0.284876 / 0.323480 (-0.038604) | 0.004011 / 0.007986 (-0.003975) | 0.002602 / 0.004328 (-0.001726) | 0.046742 / 0.004250 (0.042491) | 0.040393 / 0.037052 (0.003341) | 0.265052 / 0.258489 (0.006563) | 0.294217 / 0.293841 (0.000377) | 0.028429 / 0.128546 (-0.100118) | 0.010418 / 0.075646 (-0.065228) | 0.057285 / 0.419271 (-0.361987) | 0.032137 / 0.043533 (-0.011396) | 0.265867 / 0.255139 (0.010728) | 0.284764 / 0.283200 (0.001564) | 0.017448 / 0.141683 (-0.124235) | 1.172830 / 1.452155 (-0.279325) | 1.223982 / 1.492716 (-0.268735) |

### Benchmark: benchmark_getitem\_100B.json

| metric | get_batch_of\_1024\_random_rows | get_batch_of\_1024\_rows | get_first_row | get_last_row |
|--------|---|---|---|---|
| new / old (diff) | 0.091859 / 0.018006 (0.073853) | 0.285421 / 0.000490 (0.284931) | 0.000220 / 0.000200 (0.000020) | 0.000049 / 0.000054 (-0.000005) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.021620 / 0.037411 (-0.015792) | 0.069058 / 0.014526 (0.054532) | 0.082560 / 0.176557 (-0.093997) | 0.119511 / 0.737135 (-0.617624) | 0.082318 / 0.296338 (-0.214021) |

### Benchmark: benchmark_iterating.json

| metric | read 5000 | read 50000 | read_batch 50000 10 | read_batch 50000 100 | read_batch 50000 1000 | read_formatted numpy 5000 | read_formatted pandas 5000 | read_formatted tensorflow 5000 | read_formatted torch 5000 | read_formatted_batch numpy 5000 10 | read_formatted_batch numpy 5000 1000 | shuffled read 5000 | shuffled read 50000 | shuffled read_batch 50000 10 | shuffled read_batch 50000 100 | shuffled read_batch 50000 1000 | shuffled read_formatted numpy 5000 | shuffled read_formatted_batch numpy 5000 10 | shuffled read_formatted_batch numpy 5000 1000 |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.291499 / 0.215209 (0.076290) | 2.863352 / 2.077655 (0.785698) | 1.557242 / 1.504120 (0.053122) | 1.430170 / 1.541195 (-0.111024) | 1.432850 / 1.468490 (-0.035640) | 0.559716 / 4.584777 (-4.025061) | 2.385405 / 3.745712 (-1.360307) | 2.748938 / 5.269862 (-2.520924) | 1.740802 / 4.565676 (-2.824874) | 0.061811 / 0.424275 (-0.362465) | 0.005174 / 0.007607 (-0.002433) | 0.348687 / 0.226044 (0.122642) | 3.420120 / 2.268929 (1.151191) | 1.918278 / 55.444624 (-53.526346) | 1.631559 / 6.876477 (-5.244918) | 1.635850 / 2.142072 (-0.506222) | 0.644144 / 4.805227 (-4.161083) | 0.115823 / 6.500664 (-6.384841) | 0.041255 / 0.075469 (-0.034214) |

### Benchmark: benchmark_map_filter.json

| metric | filter | map fast-tokenizer batched | map identity | map identity batched | map no-op batched | map no-op batched numpy | map no-op batched pandas | map no-op batched pytorch | map no-op batched tensorflow |
|--------|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.960066 / 1.841788 (-0.881722) | 12.011372 / 8.074308 (3.937064) | 10.580532 / 10.191392 (0.389140) | 0.134763 / 0.680424 (-0.545661) | 0.017027 / 0.534201 (-0.517174) | 0.290484 / 0.579283 (-0.288799) | 0.285171 / 0.434364 (-0.149193) | 0.322453 / 0.540337 (-0.217884) | 0.438088 / 1.386936 (-0.948848) |

</details>
</details>

![](https://cml.dev/watermark.png#b3fc42882a2d84d7482c27063f1e19539e99b9d3 "CML watermark")


<details>
<summary>Show benchmarks</summary>

PyArrow==8.0.0

<details>
<summary>Show updated benchmarks!</summary>

### Benchmark: benchmark_array_xd.json

| metric | read_batch_formatted_as_numpy after write_array2d | read_batch_formatted_as_numpy after write_flattened_sequence | read_batch_formatted_as_numpy after write_nested_sequence | read_batch_unformated after write_array2d | read_batch_unformated after write_flattened_sequence | read_batch_unformated after write_nested_sequence | read_col_formatted_as_numpy after write_array2d | read_col_formatted_as_numpy after write_flattened_sequence | read_col_formatted_as_numpy after write_nested_sequence | read_col_unformated after write_array2d | read_col_unformated after write_flattened_sequence | read_col_unformated after write_nested_sequence | read_formatted_as_numpy after write_array2d | read_formatted_as_numpy after write_flattened_sequence | read_formatted_as_numpy after write_nested_sequence | read_unformated after write_array2d | read_unformated after write_flattened_sequence | read_unformated after write_nested_sequence | write_array2d | write_flattened_sequence | write_nested_sequence |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.005212 / 0.011353 (-0.006141) | 0.003440 / 0.011008 (-0.007568) | 0.063612 / 0.038508 (0.025104) | 0.049070 / 0.023109 (0.025961) | 0.269748 / 0.275898 (-0.006150) | 0.283270 / 0.323480 (-0.040210) | 0.002892 / 0.007986 (-0.005094) | 0.002693 / 0.004328 (-0.001635) | 0.049710 / 0.004250 (0.045459) | 0.036707 / 0.037052 (-0.000345) | 0.299035 / 0.258489 (0.040546) | 0.296443 / 0.293841 (0.002602) | 0.028095 / 0.128546 (-0.100451) | 0.010682 / 0.075646 (-0.064964) | 0.213914 / 0.419271 (-0.205358) | 0.036210 / 0.043533 (-0.007323) | 0.235720 / 0.255139 (-0.019419) | 0.252687 / 0.283200 (-0.030512) | 0.016985 / 0.141683 (-0.124698) | 1.099024 / 1.452155 (-0.353130) | 1.162970 / 1.492716 (-0.329746) |

### Benchmark: benchmark_getitem\_100B.json

| metric | get_batch_of\_1024\_random_rows | get_batch_of\_1024\_rows | get_first_row | get_last_row |
|--------|---|---|---|---|
| new / old (diff) | 0.093114 / 0.018006 (0.075108) | 0.305168 / 0.000490 (0.304678) | 0.000216 / 0.000200 (0.000016) | 0.000043 / 0.000054 (-0.000012) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.018370 / 0.037411 (-0.019041) | 0.060534 / 0.014526 (0.046008) | 0.073960 / 0.176557 (-0.102596) | 0.120325 / 0.737135 (-0.616810) | 0.073754 / 0.296338 (-0.222585) |

### Benchmark: benchmark_iterating.json

| metric | read 5000 | read 50000 | read_batch 50000 10 | read_batch 50000 100 | read_batch 50000 1000 | read_formatted numpy 5000 | read_formatted pandas 5000 | read_formatted tensorflow 5000 | read_formatted torch 5000 | read_formatted_batch numpy 5000 10 | read_formatted_batch numpy 5000 1000 | shuffled read 5000 | shuffled read 50000 | shuffled read_batch 50000 10 | shuffled read_batch 50000 100 | shuffled read_batch 50000 1000 | shuffled read_formatted numpy 5000 | shuffled read_formatted_batch numpy 5000 10 | shuffled read_formatted_batch numpy 5000 1000 |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.284244 / 0.215209 (0.069035) | 2.756854 / 2.077655 (0.679199) | 1.477304 / 1.504120 (-0.026816) | 1.374635 / 1.541195 (-0.166560) | 1.383284 / 1.468490 (-0.085206) | 0.564656 / 4.584777 (-4.020121) | 2.361719 / 3.745712 (-1.383993) | 2.794822 / 5.269862 (-2.475039) | 1.742981 / 4.565676 (-2.822696) | 0.063443 / 0.424275 (-0.360832) | 0.004952 / 0.007607 (-0.002655) | 0.342058 / 0.226044 (0.116014) | 3.351093 / 2.268929 (1.082164) | 1.857375 / 55.444624 (-53.587250) | 1.541680 / 6.876477 (-5.334797) | 1.580147 / 2.142072 (-0.561926) | 0.645216 / 4.805227 (-4.160012) | 0.118768 / 6.500664 (-6.381896) | 0.042115 / 0.075469 (-0.033354) |

### Benchmark: benchmark_map_filter.json

| metric | filter | map fast-tokenizer batched | map identity | map identity batched | map no-op batched | map no-op batched numpy | map no-op batched pandas | map no-op batched pytorch | map no-op batched tensorflow |
|--------|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.925845 / 1.841788 (-0.915943) | 11.444147 / 8.074308 (3.369839) | 10.291297 / 10.191392 (0.099905) | 0.128129 / 0.680424 (-0.552295) | 0.013774 / 0.534201 (-0.520427) | 0.289278 / 0.579283 (-0.290005) | 0.262353 / 0.434364 (-0.172011) | 0.328517 / 0.540337 (-0.211820) | 0.436050 / 1.386936 (-0.950886) |

</details>
PyArrow==latest

<details>
<summary>Show updated benchmarks!</summary>

### Benchmark: benchmark_array_xd.json

| metric | read_batch_formatted_as_numpy after write_array2d | read_batch_formatted_as_numpy after write_flattened_sequence | read_batch_formatted_as_numpy after write_nested_sequence | read_batch_unformated after write_array2d | read_batch_unformated after write_flattened_sequence | read_batch_unformated after write_nested_sequence | read_col_formatted_as_numpy after write_array2d | read_col_formatted_as_numpy after write_flattened_sequence | read_col_formatted_as_numpy after write_nested_sequence | read_col_unformated after write_array2d | read_col_unformated after write_flattened_sequence | read_col_unformated after write_nested_sequence | read_formatted_as_numpy after write_array2d | read_formatted_as_numpy after write_flattened_sequence | read_formatted_as_numpy after write_nested_sequence | read_unformated after write_array2d | read_unformated after write_flattened_sequence | read_unformated after write_nested_sequence | write_array2d | write_flattened_sequence | write_nested_sequence |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.005666 / 0.011353 (-0.005687) | 0.003691 / 0.011008 (-0.007318) | 0.049361 / 0.038508 (0.010853) | 0.054245 / 0.023109 (0.031136) | 0.274433 / 0.275898 (-0.001465) | 0.285648 / 0.323480 (-0.037832) | 0.004080 / 0.007986 (-0.003906) | 0.002666 / 0.004328 (-0.001663) | 0.047539 / 0.004250 (0.043288) | 0.041001 / 0.037052 (0.003948) | 0.296018 / 0.258489 (0.037529) | 0.294542 / 0.293841 (0.000701) | 0.030546 / 0.128546 (-0.098001) | 0.010556 / 0.075646 (-0.065090) | 0.058146 / 0.419271 (-0.361126) | 0.033407 / 0.043533 (-0.010126) | 0.263977 / 0.255139 (0.008838) | 0.286228 / 0.283200 (0.003028) | 0.018088 / 0.141683 (-0.123595) | 1.121295 / 1.452155 (-0.330860) | 1.182183 / 1.492716 (-0.310533) |

### Benchmark: benchmark_getitem\_100B.json

| metric | get_batch_of\_1024\_random_rows | get_batch_of\_1024\_rows | get_first_row | get_last_row |
|--------|---|---|---|---|
| new / old (diff) | 0.104540 / 0.018006 (0.086534) | 0.303494 / 0.000490 (0.303004) | 0.000222 / 0.000200 (0.000022) | 0.000044 / 0.000054 (-0.000010) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.021274 / 0.037411 (-0.016137) | 0.070146 / 0.014526 (0.055621) | 0.080343 / 0.176557 (-0.096213) | 0.120017 / 0.737135 (-0.617119) | 0.081303 / 0.296338 (-0.215036) |

### Benchmark: benchmark_iterating.json

| metric | read 5000 | read 50000 | read_batch 50000 10 | read_batch 50000 100 | read_batch 50000 1000 | read_formatted numpy 5000 | read_formatted pandas 5000 | read_formatted tensorflow 5000 | read_formatted torch 5000 | read_formatted_batch numpy 5000 10 | read_formatted_batch numpy 5000 1000 | shuffled read 5000 | shuffled read 50000 | shuffled read_batch 50000 10 | shuffled read_batch 50000 100 | shuffled read_batch 50000 1000 | shuffled read_formatted numpy 5000 | shuffled read_formatted_batch numpy 5000 10 | shuffled read_formatted_batch numpy 5000 1000 |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.294390 / 0.215209 (0.079181) | 2.883366 / 2.077655 (0.805711) | 1.564629 / 1.504120 (0.060509) | 1.432633 / 1.541195 (-0.108562) | 1.438786 / 1.468490 (-0.029704) | 0.569663 / 4.584777 (-4.015114) | 2.448691 / 3.745712 (-1.297021) | 2.817010 / 5.269862 (-2.452851) | 1.757274 / 4.565676 (-2.808402) | 0.064147 / 0.424275 (-0.360129) | 0.004910 / 0.007607 (-0.002697) | 0.344062 / 0.226044 (0.118018) | 3.394223 / 2.268929 (1.125294) | 1.927139 / 55.444624 (-53.517485) | 1.624983 / 6.876477 (-5.251494) | 1.629076 / 2.142072 (-0.512996) | 0.654239 / 4.805227 (-4.150988) | 0.117309 / 6.500664 (-6.383355) | 0.041067 / 0.075469 (-0.034402) |

### Benchmark: benchmark_map_filter.json

| metric | filter | map fast-tokenizer batched | map identity | map identity batched | map no-op batched | map no-op batched numpy | map no-op batched pandas | map no-op batched pytorch | map no-op batched tensorflow |
|--------|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.993184 / 1.841788 (-0.848604) | 11.969985 / 8.074308 (3.895677) | 10.363356 / 10.191392 (0.171964) | 0.130708 / 0.680424 (-0.549716) | 0.015577 / 0.534201 (-0.518624) | 0.289579 / 0.579283 (-0.289704) | 0.274875 / 0.434364 (-0.159488) | 0.326736 / 0.540337 (-0.213601) | 0.442770 / 1.386936 (-0.944166) |

</details>
</details>

![](https://cml.dev/watermark.png#796a47e388a5c5711a95bd649648608c18219ac5 "CML watermark")


Getting the same windows error as in my other PR. I couldn't reproduce on my windows machine though 🧐 

`DataFilesList` is a list so we expect to be able to get its length with zero cost, which wouldn't be the case if we make it lazy no ? 

But we don't call `len` on it, do we? And I couldn't find an instance of `DataFilesList` being used in GitHub's public repos.

`DataFilesDict` is used in some repositories in dataset scripts when people want to list files from a repo using glob patterns

Also making DataFilesList lazy would require to make the pickling more complex, since we don't want to resolve the data files when pickling. At the same time we want to get different hashes if the data files and origin metadata are different so revolving the patterns is needed in that case (we hash the data files when creating the config_id, used in the cache)

> `DataFilesDict` is used in some repositories in dataset scripts when people want to list files from a repo using glob patterns

Would be interesting to know how often these scripts call `len` or do random access on `DataFilesList`.

Still, I think we should opt for a solution that makes more sense for us. To avoid the breaking change, we can define a `BuilderConfig.data_files` property that resolves this iterable. 

> Also making DataFilesList lazy would require to make the pickling more complex, since we don't want to resolve the data files when pickling. At the same time we want to get different hashes if the data files and origin metadata are different so revolving the patterns is needed in that case (we hash the data files when creating the config_id, used in the cache)

The `BuilderConfig.data_files` property suggested above should address this, no? 

I think we should be more careful not to make our API needlessly complex because of the YAML README feature. And if this can't be avoided, we should probably refactor the builder API.

> The BuilderConfig.data_files property suggested above should address this, no?

That works indeed ! let me try something

Implementing lazy DataFilesList and .data_files brings more complexity (less readable, more bad side effects) so I think the current solution is the best one

I opened https://github.com/huggingface/datasets/pull/6493 to continue this and fix conflicts with https://github.com/huggingface/datasets/pull/6459