Title: Improve logging
State: closed

Adds the StreamHandler (as `hfh` and `transformers` do) to the library's logger to log INFO messages and logs the messages about "loading a cached result" (and some other warnings) as INFO

(Also removes the `leave=False` arg in the progress bars to be consistent with `hfh` and `transformers` - progress bars serve as an indicator that a result is not cached, so it makes more sense not to delete them)

Fix #2832, fix https://github.com/huggingface/datasets/issues/1948, fix https://github.com/huggingface/datasets/issues/5444

Comments: _The documentation is not available anymore as the PR was closed or merged._<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) | 0.007782 / 0.011353 (-0.003571) | 0.004451 / 0.011008 (-0.006557) | 0.099928 / 0.038508 (0.061420) | 0.081534 / 0.023109 (0.058425) | 0.379382 / 0.275898 (0.103484) | 0.410652 / 0.323480 (0.087172) | 0.005967 / 0.007986 (-0.002019) | 0.003702 / 0.004328 (-0.000627) | 0.076359 / 0.004250 (0.072109) | 0.066721 / 0.037052 (0.029669) | 0.383595 / 0.258489 (0.125106) | 0.423854 / 0.293841 (0.130013) | 0.032796 / 0.128546 (-0.095750) | 0.009728 / 0.075646 (-0.065918) | 0.344347 / 0.419271 (-0.074925) | 0.056320 / 0.043533 (0.012788) | 0.379974 / 0.255139 (0.124835) | 0.401294 / 0.283200 (0.118094) | 0.024110 / 0.141683 (-0.117572) | 1.804194 / 1.452155 (0.352039) | 1.860240 / 1.492716 (0.367523) |

### 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) | 0.233803 / 0.018006 (0.215797) | 0.506893 / 0.000490 (0.506404) | 0.003894 / 0.000200 (0.003694) | 0.000090 / 0.000054 (0.000035) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.033328 / 0.037411 (-0.004083) | 0.098661 / 0.014526 (0.084136) | 0.114971 / 0.176557 (-0.061586) | 0.186815 / 0.737135 (-0.550321) | 0.115490 / 0.296338 (-0.180848) |

### 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) | 0.422590 / 0.215209 (0.207381) | 4.277189 / 2.077655 (2.199535) | 2.095565 / 1.504120 (0.591445) | 2.040825 / 1.541195 (0.499630) | 2.162562 / 1.468490 (0.694072) | 0.578602 / 4.584777 (-4.006175) | 4.203474 / 3.745712 (0.457762) | 6.674595 / 5.269862 (1.404734) | 3.913251 / 4.565676 (-0.652426) | 0.067777 / 0.424275 (-0.356498) | 0.008716 / 0.007607 (0.001109) | 0.548704 / 0.226044 (0.322660) | 5.162120 / 2.268929 (2.893192) | 2.600250 / 55.444624 (-52.844374) | 2.232730 / 6.876477 (-4.643747) | 2.485617 / 2.142072 (0.343544) | 0.650872 / 4.805227 (-4.154355) | 0.148022 / 6.500664 (-6.352642) | 0.064795 / 0.075469 (-0.010674) |

### 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) | 1.399439 / 1.841788 (-0.442349) | 22.438959 / 8.074308 (14.364651) | 16.447831 / 10.191392 (6.256439) | 0.202003 / 0.680424 (-0.478421) | 0.026200 / 0.534201 (-0.508001) | 0.472966 / 0.579283 (-0.106317) | 0.491621 / 0.434364 (0.057257) | 0.551580 / 0.540337 (0.011242) | 0.751420 / 1.386936 (-0.635516) |

</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) | 0.007241 / 0.011353 (-0.004112) | 0.004434 / 0.011008 (-0.006574) | 0.075872 / 0.038508 (0.037364) | 0.080094 / 0.023109 (0.056985) | 0.459244 / 0.275898 (0.183346) | 0.492482 / 0.323480 (0.169002) | 0.005791 / 0.007986 (-0.002194) | 0.003657 / 0.004328 (-0.000671) | 0.075214 / 0.004250 (0.070964) | 0.064208 / 0.037052 (0.027156) | 0.464195 / 0.258489 (0.205706) | 0.497809 / 0.293841 (0.203968) | 0.036301 / 0.128546 (-0.092245) | 0.009855 / 0.075646 (-0.065791) | 0.080826 / 0.419271 (-0.338445) | 0.056700 / 0.043533 (0.013167) | 0.452850 / 0.255139 (0.197711) | 0.490738 / 0.283200 (0.207538) | 0.024145 / 0.141683 (-0.117538) | 1.689911 / 1.452155 (0.237757) | 1.789803 / 1.492716 (0.297087) |

### 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) | 0.247741 / 0.018006 (0.229735) | 0.486769 / 0.000490 (0.486279) | 0.000418 / 0.000200 (0.000218) | 0.000060 / 0.000054 (0.000005) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.036317 / 0.037411 (-0.001094) | 0.104943 / 0.014526 (0.090417) | 0.120972 / 0.176557 (-0.055585) | 0.188461 / 0.737135 (-0.548674) | 0.120926 / 0.296338 (-0.175412) |

### 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) | 0.465788 / 0.215209 (0.250579) | 4.662369 / 2.077655 (2.584714) | 2.442241 / 1.504120 (0.938121) | 2.266328 / 1.541195 (0.725133) | 2.438998 / 1.468490 (0.970508) | 0.531384 / 4.584777 (-4.053393) | 4.125286 / 3.745712 (0.379574) | 3.920912 / 5.269862 (-1.348950) | 2.292149 / 4.565676 (-2.273528) | 0.070146 / 0.424275 (-0.354129) | 0.008887 / 0.007607 (0.001280) | 0.598181 / 0.226044 (0.372137) | 5.726454 / 2.268929 (3.457526) | 3.081836 / 55.444624 (-52.362788) | 2.683508 / 6.876477 (-4.192969) | 2.587350 / 2.142072 (0.445278) | 0.604736 / 4.805227 (-4.200491) | 0.141303 / 6.500664 (-6.359362) | 0.065020 / 0.075469 (-0.010449) |

### 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) | 1.481850 / 1.841788 (-0.359938) | 22.259592 / 8.074308 (14.185284) | 16.304290 / 10.191392 (6.112898) | 0.173514 / 0.680424 (-0.506909) | 0.021590 / 0.534201 (-0.512611) | 0.471753 / 0.579283 (-0.107531) | 0.472132 / 0.434364 (0.037768) | 0.563344 / 0.540337 (0.023007) | 0.738509 / 1.386936 (-0.648427) |

</details>
</details>

![](https://cml.dev/watermark.png#1cb7ae56dbd814945a4982c63bf0e50859a7b93a "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) | 0.005910 / 0.011353 (-0.005443) | 0.004372 / 0.011008 (-0.006636) | 0.081583 / 0.038508 (0.043075) | 0.069598 / 0.023109 (0.046488) | 0.346360 / 0.275898 (0.070462) | 0.360733 / 0.323480 (0.037254) | 0.004725 / 0.007986 (-0.003261) | 0.003106 / 0.004328 (-0.001222) | 0.059916 / 0.004250 (0.055666) | 0.053242 / 0.037052 (0.016189) | 0.353551 / 0.258489 (0.095062) | 0.373052 / 0.293841 (0.079211) | 0.029036 / 0.128546 (-0.099510) | 0.007894 / 0.075646 (-0.067753) | 0.284131 / 0.419271 (-0.135140) | 0.049348 / 0.043533 (0.005815) | 0.347409 / 0.255139 (0.092270) | 0.355029 / 0.283200 (0.071830) | 0.022511 / 0.141683 (-0.119171) | 1.454495 / 1.452155 (0.002340) | 1.439551 / 1.492716 (-0.053166) |

### 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) | 0.218889 / 0.018006 (0.200883) | 0.478734 / 0.000490 (0.478244) | 0.003758 / 0.000200 (0.003558) | 0.000083 / 0.000054 (0.000029) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.025759 / 0.037411 (-0.011653) | 0.082511 / 0.014526 (0.067985) | 0.087578 / 0.176557 (-0.088979) | 0.137760 / 0.737135 (-0.599375) | 0.093312 / 0.296338 (-0.203027) |

### 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) | 0.378963 / 0.215209 (0.163754) | 3.645846 / 2.077655 (1.568191) | 1.741135 / 1.504120 (0.237015) | 1.599166 / 1.541195 (0.057972) | 1.610817 / 1.468490 (0.142327) | 0.459209 / 4.584777 (-4.125568) | 3.484857 / 3.745712 (-0.260855) | 3.928109 / 5.269862 (-1.341752) | 2.419784 / 4.565676 (-2.145892) | 0.051987 / 0.424275 (-0.372288) | 0.006495 / 0.007607 (-0.001112) | 0.427311 / 0.226044 (0.201267) | 4.226378 / 2.268929 (1.957450) | 2.212331 / 55.444624 (-53.232293) | 1.916213 / 6.876477 (-4.960264) | 1.978809 / 2.142072 (-0.163263) | 0.547351 / 4.805227 (-4.257876) | 0.121110 / 6.500664 (-6.379554) | 0.054163 / 0.075469 (-0.021306) |

### 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) | 1.228594 / 1.841788 (-0.613193) | 19.410901 / 8.074308 (11.336593) | 13.014722 / 10.191392 (2.823330) | 0.156449 / 0.680424 (-0.523975) | 0.021032 / 0.534201 (-0.513169) | 0.403976 / 0.579283 (-0.175307) | 0.413885 / 0.434364 (-0.020479) | 0.470465 / 0.540337 (-0.069873) | 0.641322 / 1.386936 (-0.745614) |

</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) | 0.007210 / 0.011353 (-0.004143) | 0.003824 / 0.011008 (-0.007185) | 0.058227 / 0.038508 (0.019719) | 0.076211 / 0.023109 (0.053102) | 0.336626 / 0.275898 (0.060728) | 0.420542 / 0.323480 (0.097062) | 0.006178 / 0.007986 (-0.001808) | 0.003332 / 0.004328 (-0.000997) | 0.058073 / 0.004250 (0.053823) | 0.062485 / 0.037052 (0.025432) | 0.386175 / 0.258489 (0.127686) | 0.415659 / 0.293841 (0.121818) | 0.031264 / 0.128546 (-0.097282) | 0.007502 / 0.075646 (-0.068144) | 0.072079 / 0.419271 (-0.347192) | 0.055860 / 0.043533 (0.012327) | 0.343508 / 0.255139 (0.088369) | 0.437844 / 0.283200 (0.154645) | 0.032852 / 0.141683 (-0.108831) | 1.409241 / 1.452155 (-0.042913) | 1.623949 / 1.492716 (0.131233) |

### 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) | 0.207511 / 0.018006 (0.189504) | 0.464149 / 0.000490 (0.463660) | 0.003248 / 0.000200 (0.003048) | 0.000226 / 0.000054 (0.000172) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.030767 / 0.037411 (-0.006645) | 0.079169 / 0.014526 (0.064643) | 0.093111 / 0.176557 (-0.083445) | 0.153369 / 0.737135 (-0.583767) | 0.092939 / 0.296338 (-0.203400) |

### 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) | 0.375602 / 0.215209 (0.160392) | 3.968612 / 2.077655 (1.890957) | 2.081749 / 1.504120 (0.577629) | 1.899772 / 1.541195 (0.358577) | 1.847923 / 1.468490 (0.379433) | 0.442867 / 4.584777 (-4.141910) | 3.646664 / 3.745712 (-0.099048) | 5.870600 / 5.269862 (0.600739) | 3.356698 / 4.565676 (-1.208979) | 0.051422 / 0.424275 (-0.372853) | 0.006006 / 0.007607 (-0.001601) | 0.442439 / 0.226044 (0.216395) | 4.466256 / 2.268929 (2.197328) | 2.483832 / 55.444624 (-52.960792) | 2.105612 / 6.876477 (-4.770865) | 2.060650 / 2.142072 (-0.081422) | 0.531119 / 4.805227 (-4.274108) | 0.123436 / 6.500664 (-6.377228) | 0.059838 / 0.075469 (-0.015632) |

### 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) | 1.283042 / 1.841788 (-0.558746) | 19.688251 / 8.074308 (11.613943) | 13.346386 / 10.191392 (3.154994) | 0.197463 / 0.680424 (-0.482961) | 0.018484 / 0.534201 (-0.515717) | 0.391727 / 0.579283 (-0.187556) | 0.425061 / 0.434364 (-0.009303) | 0.448177 / 0.540337 (-0.092160) | 0.653694 / 1.386936 (-0.733242) |

</details>
</details>

![](https://cml.dev/watermark.png#01604752fe89d290479fa406b1a24ac1f346826e "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) | 0.008966 / 0.011353 (-0.002387) | 0.005195 / 0.011008 (-0.005813) | 0.102879 / 0.038508 (0.064371) | 0.090902 / 0.023109 (0.067792) | 0.434397 / 0.275898 (0.158498) | 0.454013 / 0.323480 (0.130534) | 0.008507 / 0.007986 (0.000521) | 0.005000 / 0.004328 (0.000671) | 0.075789 / 0.004250 (0.071538) | 0.067608 / 0.037052 (0.030555) | 0.435091 / 0.258489 (0.176602) | 0.469411 / 0.293841 (0.175570) | 0.050859 / 0.128546 (-0.077687) | 0.013560 / 0.075646 (-0.062086) | 0.345473 / 0.419271 (-0.073799) | 0.094974 / 0.043533 (0.051441) | 0.429626 / 0.255139 (0.174487) | 0.434290 / 0.283200 (0.151090) | 0.052269 / 0.141683 (-0.089413) | 1.700549 / 1.452155 (0.248395) | 1.890693 / 1.492716 (0.397976) |

### 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) | 0.296618 / 0.018006 (0.278612) | 0.613908 / 0.000490 (0.613419) | 0.000484 / 0.000200 (0.000284) | 0.000086 / 0.000054 (0.000032) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.034346 / 0.037411 (-0.003065) | 0.096836 / 0.014526 (0.082310) | 0.113332 / 0.176557 (-0.063224) | 0.194464 / 0.737135 (-0.542671) | 0.111732 / 0.296338 (-0.184606) |

### 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) | 0.624954 / 0.215209 (0.409745) | 6.442193 / 2.077655 (4.364538) | 2.818331 / 1.504120 (1.314211) | 2.529607 / 1.541195 (0.988413) | 2.549026 / 1.468490 (1.080536) | 0.967367 / 4.584777 (-3.617410) | 5.446885 / 3.745712 (1.701173) | 6.259099 / 5.269862 (0.989237) | 3.652936 / 4.565676 (-0.912740) | 0.106420 / 0.424275 (-0.317855) | 0.011293 / 0.007607 (0.003686) | 0.772026 / 0.226044 (0.545982) | 7.823986 / 2.268929 (5.555057) | 3.725328 / 55.444624 (-51.719297) | 2.851489 / 6.876477 (-4.024988) | 3.013722 / 2.142072 (0.871649) | 1.045090 / 4.805227 (-3.760137) | 0.213174 / 6.500664 (-6.287490) | 0.077104 / 0.075469 (0.001635) |

### 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) | 1.657135 / 1.841788 (-0.184652) | 24.547604 / 8.074308 (16.473296) | 19.989533 / 10.191392 (9.798141) | 0.257139 / 0.680424 (-0.423285) | 0.028448 / 0.534201 (-0.505753) | 0.490801 / 0.579283 (-0.088482) | 0.628072 / 0.434364 (0.193708) | 0.584873 / 0.540337 (0.044536) | 0.825258 / 1.386936 (-0.561678) |

</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) | 0.009258 / 0.011353 (-0.002095) | 0.005660 / 0.011008 (-0.005348) | 0.080577 / 0.038508 (0.042069) | 0.095786 / 0.023109 (0.072676) | 0.473334 / 0.275898 (0.197436) | 0.527962 / 0.323480 (0.204482) | 0.006537 / 0.007986 (-0.001449) | 0.004411 / 0.004328 (0.000083) | 0.080702 / 0.004250 (0.076452) | 0.077020 / 0.037052 (0.039968) | 0.483205 / 0.258489 (0.224716) | 0.556916 / 0.293841 (0.263076) | 0.047670 / 0.128546 (-0.080877) | 0.016647 / 0.075646 (-0.058999) | 0.090653 / 0.419271 (-0.328619) | 0.062122 / 0.043533 (0.018589) | 0.498326 / 0.255139 (0.243187) | 0.546572 / 0.283200 (0.263372) | 0.037525 / 0.141683 (-0.104157) | 1.869520 / 1.452155 (0.417365) | 1.915335 / 1.492716 (0.422619) |

### 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) | 0.248287 / 0.018006 (0.230281) | 0.611440 / 0.000490 (0.610950) | 0.004102 / 0.000200 (0.003902) | 0.000132 / 0.000054 (0.000078) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.038228 / 0.037411 (0.000817) | 0.103510 / 0.014526 (0.088984) | 0.114337 / 0.176557 (-0.062219) | 0.189662 / 0.737135 (-0.547473) | 0.119078 / 0.296338 (-0.177260) |

### 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) | 0.606622 / 0.215209 (0.391413) | 6.053900 / 2.077655 (3.976246) | 2.857972 / 1.504120 (1.353852) | 2.549756 / 1.541195 (1.008561) | 2.584557 / 1.468490 (1.116067) | 0.930431 / 4.584777 (-3.654346) | 5.524077 / 3.745712 (1.778365) | 7.858406 / 5.269862 (2.588545) | 4.890697 / 4.565676 (0.325020) | 0.095356 / 0.424275 (-0.328919) | 0.008614 / 0.007607 (0.001007) | 0.774227 / 0.226044 (0.548182) | 7.470215 / 2.268929 (5.201287) | 3.784820 / 55.444624 (-51.659805) | 3.199364 / 6.876477 (-3.677113) | 3.212002 / 2.142072 (1.069929) | 1.054104 / 4.805227 (-3.751123) | 0.226044 / 6.500664 (-6.274620) | 0.092237 / 0.075469 (0.016768) |

### 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) | 1.801054 / 1.841788 (-0.040734) | 24.220404 / 8.074308 (16.146096) | 21.652936 / 10.191392 (11.461544) | 0.247004 / 0.680424 (-0.433420) | 0.029651 / 0.534201 (-0.504550) | 0.475702 / 0.579283 (-0.103581) | 0.621121 / 0.434364 (0.186757) | 0.570489 / 0.540337 (0.030151) | 0.768840 / 1.386936 (-0.618096) |

</details>
</details>

![](https://cml.dev/watermark.png#b2fc21eda345643fb57d1d1167ebed9043310911 "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) | 0.009223 / 0.011353 (-0.002130) | 0.005750 / 0.011008 (-0.005258) | 0.105264 / 0.038508 (0.066756) | 0.088478 / 0.023109 (0.065369) | 0.461119 / 0.275898 (0.185221) | 0.481115 / 0.323480 (0.157636) | 0.006366 / 0.007986 (-0.001619) | 0.004515 / 0.004328 (0.000186) | 0.079296 / 0.004250 (0.075045) | 0.063483 / 0.037052 (0.026430) | 0.444490 / 0.258489 (0.186001) | 0.496474 / 0.293841 (0.202634) | 0.048568 / 0.128546 (-0.079978) | 0.013574 / 0.075646 (-0.062073) | 0.379213 / 0.419271 (-0.040059) | 0.086464 / 0.043533 (0.042932) | 0.437526 / 0.255139 (0.182387) | 0.447117 / 0.283200 (0.163917) | 0.049502 / 0.141683 (-0.092180) | 1.749146 / 1.452155 (0.296992) | 1.831082 / 1.492716 (0.338365) |

### 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) | 0.268205 / 0.018006 (0.250199) | 0.627406 / 0.000490 (0.626917) | 0.005439 / 0.000200 (0.005239) | 0.000128 / 0.000054 (0.000074) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.030564 / 0.037411 (-0.006848) | 0.096365 / 0.014526 (0.081840) | 0.117484 / 0.176557 (-0.059072) | 0.189104 / 0.737135 (-0.548032) | 0.118073 / 0.296338 (-0.178266) |

### 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) | 0.618229 / 0.215209 (0.403019) | 6.437853 / 2.077655 (4.360199) | 2.789946 / 1.504120 (1.285826) | 2.339245 / 1.541195 (0.798050) | 2.588779 / 1.468490 (1.120289) | 0.921008 / 4.584777 (-3.663769) | 5.402940 / 3.745712 (1.657227) | 4.818783 / 5.269862 (-0.451078) | 3.162259 / 4.565676 (-1.403417) | 0.108501 / 0.424275 (-0.315774) | 0.009384 / 0.007607 (0.001777) | 0.766811 / 0.226044 (0.540766) | 7.624629 / 2.268929 (5.355701) | 3.442420 / 55.444624 (-52.002204) | 2.759967 / 6.876477 (-4.116510) | 3.049644 / 2.142072 (0.907572) | 1.113308 / 4.805227 (-3.691919) | 0.223923 / 6.500664 (-6.276741) | 0.079156 / 0.075469 (0.003687) |

### 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) | 1.683318 / 1.841788 (-0.158470) | 25.062141 / 8.074308 (16.987833) | 21.777131 / 10.191392 (11.585739) | 0.266939 / 0.680424 (-0.413485) | 0.029670 / 0.534201 (-0.504531) | 0.476761 / 0.579283 (-0.102522) | 0.622080 / 0.434364 (0.187716) | 0.601781 / 0.540337 (0.061443) | 0.785126 / 1.386936 (-0.601811) |

</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) | 0.010198 / 0.011353 (-0.001155) | 0.005777 / 0.011008 (-0.005231) | 0.083003 / 0.038508 (0.044495) | 0.093411 / 0.023109 (0.070302) | 0.496178 / 0.275898 (0.220280) | 0.554670 / 0.323480 (0.231190) | 0.008351 / 0.007986 (0.000365) | 0.004678 / 0.004328 (0.000350) | 0.083631 / 0.004250 (0.079381) | 0.075538 / 0.037052 (0.038485) | 0.492410 / 0.258489 (0.233921) | 0.545209 / 0.293841 (0.251368) | 0.048365 / 0.128546 (-0.080181) | 0.014219 / 0.075646 (-0.061427) | 0.100749 / 0.419271 (-0.318523) | 0.063431 / 0.043533 (0.019898) | 0.511115 / 0.255139 (0.255976) | 0.532965 / 0.283200 (0.249765) | 0.037968 / 0.141683 (-0.103715) | 1.940268 / 1.452155 (0.488113) | 2.032934 / 1.492716 (0.540217) |

### 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) | 0.238179 / 0.018006 (0.220172) | 0.605767 / 0.000490 (0.605277) | 0.004033 / 0.000200 (0.003833) | 0.000125 / 0.000054 (0.000071) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.036436 / 0.037411 (-0.000975) | 0.108034 / 0.014526 (0.093509) | 0.118624 / 0.176557 (-0.057933) | 0.183079 / 0.737135 (-0.554056) | 0.121739 / 0.296338 (-0.174600) |

### 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) | 0.630538 / 0.215209 (0.415329) | 6.552184 / 2.077655 (4.474529) | 3.003412 / 1.504120 (1.499292) | 2.669026 / 1.541195 (1.127832) | 2.791109 / 1.468490 (1.322619) | 0.884003 / 4.584777 (-3.700774) | 5.538660 / 3.745712 (1.792947) | 5.126708 / 5.269862 (-0.143154) | 3.120825 / 4.565676 (-1.444852) | 0.101178 / 0.424275 (-0.323097) | 0.009027 / 0.007607 (0.001420) | 0.785914 / 0.226044 (0.559869) | 7.994720 / 2.268929 (5.725792) | 4.061996 / 55.444624 (-51.382629) | 3.263230 / 6.876477 (-3.613247) | 3.288622 / 2.142072 (1.146550) | 1.141867 / 4.805227 (-3.663360) | 0.255287 / 6.500664 (-6.245378) | 0.100637 / 0.075469 (0.025168) |

### 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) | 1.769821 / 1.841788 (-0.071967) | 24.994008 / 8.074308 (16.919700) | 21.765971 / 10.191392 (11.574579) | 0.268493 / 0.680424 (-0.411931) | 0.028047 / 0.534201 (-0.506154) | 0.489472 / 0.579283 (-0.089811) | 0.594809 / 0.434364 (0.160445) | 0.613578 / 0.540337 (0.073241) | 0.879360 / 1.386936 (-0.507576) |

</details>
</details>

![](https://cml.dev/watermark.png#b85b1154aef2a9ab4d558f60d91623f2cc1583c4 "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) | 0.006003 / 0.011353 (-0.005350) | 0.003590 / 0.011008 (-0.007418) | 0.084657 / 0.038508 (0.046149) | 0.057884 / 0.023109 (0.034775) | 0.318347 / 0.275898 (0.042449) | 0.345976 / 0.323480 (0.022496) | 0.004706 / 0.007986 (-0.003279) | 0.002921 / 0.004328 (-0.001407) | 0.061850 / 0.004250 (0.057600) | 0.050558 / 0.037052 (0.013505) | 0.320877 / 0.258489 (0.062388) | 0.356062 / 0.293841 (0.062222) | 0.027511 / 0.128546 (-0.101035) | 0.007954 / 0.075646 (-0.067693) | 0.260290 / 0.419271 (-0.158981) | 0.051207 / 0.043533 (0.007674) | 0.334423 / 0.255139 (0.079284) | 0.338575 / 0.283200 (0.055375) | 0.022330 / 0.141683 (-0.119353) | 1.445446 / 1.452155 (-0.006709) | 1.500626 / 1.492716 (0.007910) |

### 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) | 0.192440 / 0.018006 (0.174433) | 0.428455 / 0.000490 (0.427965) | 0.000318 / 0.000200 (0.000118) | 0.000056 / 0.000054 (0.000002) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.022933 / 0.037411 (-0.014478) | 0.072795 / 0.014526 (0.058269) | 0.081149 / 0.176557 (-0.095407) | 0.142941 / 0.737135 (-0.594195) | 0.082410 / 0.296338 (-0.213928) |

### 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) | 0.405220 / 0.215209 (0.190011) | 4.048585 / 2.077655 (1.970931) | 2.027908 / 1.504120 (0.523788) | 1.887828 / 1.541195 (0.346633) | 2.131780 / 1.468490 (0.663290) | 0.502847 / 4.584777 (-4.081930) | 3.069498 / 3.745712 (-0.676215) | 4.094774 / 5.269862 (-1.175088) | 2.544004 / 4.565676 (-2.021673) | 0.059540 / 0.424275 (-0.364735) | 0.006501 / 0.007607 (-0.001106) | 0.477218 / 0.226044 (0.251173) | 4.764961 / 2.268929 (2.496032) | 2.434594 / 55.444624 (-53.010030) | 2.104833 / 6.876477 (-4.771644) | 2.263059 / 2.142072 (0.120987) | 0.591755 / 4.805227 (-4.213472) | 0.131167 / 6.500664 (-6.369497) | 0.061808 / 0.075469 (-0.013661) |

### 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) | 1.345364 / 1.841788 (-0.496424) | 18.122584 / 8.074308 (10.048276) | 13.318689 / 10.191392 (3.127297) | 0.144526 / 0.680424 (-0.535898) | 0.016997 / 0.534201 (-0.517204) | 0.336036 / 0.579283 (-0.243247) | 0.359532 / 0.434364 (-0.074832) | 0.386945 / 0.540337 (-0.153392) | 0.538659 / 1.386936 (-0.848277) |

</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) | 0.006088 / 0.011353 (-0.005265) | 0.003684 / 0.011008 (-0.007324) | 0.062340 / 0.038508 (0.023832) | 0.058461 / 0.023109 (0.035352) | 0.360134 / 0.275898 (0.084236) | 0.393298 / 0.323480 (0.069818) | 0.004664 / 0.007986 (-0.003322) | 0.002909 / 0.004328 (-0.001420) | 0.062668 / 0.004250 (0.058418) | 0.050145 / 0.037052 (0.013092) | 0.361897 / 0.258489 (0.103408) | 0.402008 / 0.293841 (0.108167) | 0.027491 / 0.128546 (-0.101055) | 0.008113 / 0.075646 (-0.067534) | 0.068114 / 0.419271 (-0.351157) | 0.043303 / 0.043533 (-0.000230) | 0.360569 / 0.255139 (0.105430) | 0.387144 / 0.283200 (0.103944) | 0.020194 / 0.141683 (-0.121489) | 1.418066 / 1.452155 (-0.034089) | 1.475640 / 1.492716 (-0.017076) |

### 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) | 0.200291 / 0.018006 (0.182285) | 0.432298 / 0.000490 (0.431809) | 0.003303 / 0.000200 (0.003103) | 0.000075 / 0.000054 (0.000020) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.027749 / 0.037411 (-0.009662) | 0.081890 / 0.014526 (0.067364) | 0.094319 / 0.176557 (-0.082238) | 0.148646 / 0.737135 (-0.588490) | 0.091830 / 0.296338 (-0.204509) |

### 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) | 0.433546 / 0.215209 (0.218337) | 4.326855 / 2.077655 (2.249200) | 2.230186 / 1.504120 (0.726066) | 2.052524 / 1.541195 (0.511329) | 2.117270 / 1.468490 (0.648779) | 0.500331 / 4.584777 (-4.084446) | 3.113662 / 3.745712 (-0.632050) | 2.931540 / 5.269862 (-2.338322) | 1.853615 / 4.565676 (-2.712062) | 0.058250 / 0.424275 (-0.366025) | 0.006546 / 0.007607 (-0.001061) | 0.508850 / 0.226044 (0.282806) | 5.081809 / 2.268929 (2.812880) | 2.687037 / 55.444624 (-52.757588) | 2.369317 / 6.876477 (-4.507160) | 2.383549 / 2.142072 (0.241477) | 0.587039 / 4.805227 (-4.218188) | 0.125858 / 6.500664 (-6.374806) | 0.062522 / 0.075469 (-0.012947) |

### 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) | 1.294929 / 1.841788 (-0.546858) | 18.056312 / 8.074308 (9.982004) | 13.755117 / 10.191392 (3.563725) | 0.132037 / 0.680424 (-0.548387) | 0.016866 / 0.534201 (-0.517335) | 0.339040 / 0.579283 (-0.240243) | 0.364371 / 0.434364 (-0.069993) | 0.399533 / 0.540337 (-0.140804) | 0.564524 / 1.386936 (-0.822412) |

</details>
</details>

![](https://cml.dev/watermark.png#64b811c13a7982015d7e078e3d693ce5359a05a2 "CML watermark")
@lhoestq This bar comes from: https://github.com/huggingface/datasets/blob/b8067c0262073891180869f700ebef5ac3dc5cce/src/datasets/builder.py#L1156-L1166

Do you prefer not showing it or, e.g.,  having `desc="Generating splits"`?No strong opinion. Since there is a "Generating" progress bar already, maybe it can be "Preparing splits" (ref to download_and_prepare)<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) | 0.006348 / 0.011353 (-0.005005) | 0.003721 / 0.011008 (-0.007287) | 0.084039 / 0.038508 (0.045531) | 0.067627 / 0.023109 (0.044517) | 0.308372 / 0.275898 (0.032474) | 0.335131 / 0.323480 (0.011652) | 0.005157 / 0.007986 (-0.002829) | 0.003266 / 0.004328 (-0.001062) | 0.065374 / 0.004250 (0.061124) | 0.055550 / 0.037052 (0.018498) | 0.314001 / 0.258489 (0.055512) | 0.350510 / 0.293841 (0.056669) | 0.030859 / 0.128546 (-0.097688) | 0.008286 / 0.075646 (-0.067361) | 0.287122 / 0.419271 (-0.132149) | 0.051494 / 0.043533 (0.007961) | 0.309868 / 0.255139 (0.054729) | 0.325845 / 0.283200 (0.042645) | 0.022622 / 0.141683 (-0.119061) | 1.468730 / 1.452155 (0.016575) | 1.547871 / 1.492716 (0.055155) |

### 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) | 0.202763 / 0.018006 (0.184757) | 0.456403 / 0.000490 (0.455914) | 0.003116 / 0.000200 (0.002916) | 0.000079 / 0.000054 (0.000024) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.027297 / 0.037411 (-0.010114) | 0.081204 / 0.014526 (0.066678) | 0.094274 / 0.176557 (-0.082282) | 0.154391 / 0.737135 (-0.582744) | 0.094312 / 0.296338 (-0.202026) |

### 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) | 0.387382 / 0.215209 (0.172173) | 3.865597 / 2.077655 (1.787943) | 1.855959 / 1.504120 (0.351839) | 1.685411 / 1.541195 (0.144216) | 1.732127 / 1.468490 (0.263637) | 0.482230 / 4.584777 (-4.102547) | 3.664947 / 3.745712 (-0.080765) | 5.114379 / 5.269862 (-0.155482) | 3.102803 / 4.565676 (-1.462873) | 0.056509 / 0.424275 (-0.367766) | 0.007230 / 0.007607 (-0.000377) | 0.456788 / 0.226044 (0.230744) | 4.575831 / 2.268929 (2.306902) | 2.335249 / 55.444624 (-53.109375) | 2.003805 / 6.876477 (-4.872672) | 2.141788 / 2.142072 (-0.000285) | 0.577501 / 4.805227 (-4.227726) | 0.130264 / 6.500664 (-6.370400) | 0.058889 / 0.075469 (-0.016580) |

### 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) | 1.252673 / 1.841788 (-0.589115) | 18.676897 / 8.074308 (10.602589) | 13.988101 / 10.191392 (3.796709) | 0.151376 / 0.680424 (-0.529048) | 0.018104 / 0.534201 (-0.516097) | 0.388413 / 0.579283 (-0.190870) | 0.414841 / 0.434364 (-0.019523) | 0.456078 / 0.540337 (-0.084259) | 0.641715 / 1.386936 (-0.745221) |

</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) | 0.006315 / 0.011353 (-0.005038) | 0.003847 / 0.011008 (-0.007162) | 0.063989 / 0.038508 (0.025481) | 0.068244 / 0.023109 (0.045135) | 0.416201 / 0.275898 (0.140303) | 0.438446 / 0.323480 (0.114966) | 0.005820 / 0.007986 (-0.002166) | 0.003165 / 0.004328 (-0.001163) | 0.064143 / 0.004250 (0.059892) | 0.056529 / 0.037052 (0.019477) | 0.414916 / 0.258489 (0.156427) | 0.450771 / 0.293841 (0.156930) | 0.030611 / 0.128546 (-0.097935) | 0.008289 / 0.075646 (-0.067357) | 0.070725 / 0.419271 (-0.348546) | 0.047998 / 0.043533 (0.004465) | 0.405609 / 0.255139 (0.150470) | 0.421895 / 0.283200 (0.138696) | 0.022135 / 0.141683 (-0.119548) | 1.444238 / 1.452155 (-0.007916) | 1.515823 / 1.492716 (0.023107) |

### 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) | 0.227043 / 0.018006 (0.209037) | 0.439732 / 0.000490 (0.439242) | 0.001267 / 0.000200 (0.001067) | 0.000070 / 0.000054 (0.000016) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.029082 / 0.037411 (-0.008329) | 0.086201 / 0.014526 (0.071675) | 0.098653 / 0.176557 (-0.077903) | 0.152574 / 0.737135 (-0.584561) | 0.100696 / 0.296338 (-0.195642) |

### 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) | 0.411243 / 0.215209 (0.196034) | 4.100170 / 2.077655 (2.022515) | 2.118310 / 1.504120 (0.614190) | 1.935646 / 1.541195 (0.394451) | 1.970798 / 1.468490 (0.502307) | 0.478635 / 4.584777 (-4.106142) | 3.589396 / 3.745712 (-0.156316) | 3.312462 / 5.269862 (-1.957399) | 1.963081 / 4.565676 (-2.602595) | 0.056392 / 0.424275 (-0.367883) | 0.007134 / 0.007607 (-0.000473) | 0.485131 / 0.226044 (0.259086) | 4.838946 / 2.268929 (2.570017) | 2.624550 / 55.444624 (-52.820075) | 2.223046 / 6.876477 (-4.653431) | 2.230642 / 2.142072 (0.088570) | 0.594892 / 4.805227 (-4.210335) | 0.130523 / 6.500664 (-6.370141) | 0.059585 / 0.075469 (-0.015884) |

### 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) | 1.329941 / 1.841788 (-0.511847) | 19.199057 / 8.074308 (11.124748) | 14.166009 / 10.191392 (3.974617) | 0.190595 / 0.680424 (-0.489829) | 0.018419 / 0.534201 (-0.515782) | 0.392031 / 0.579283 (-0.187252) | 0.409395 / 0.434364 (-0.024969) | 0.475930 / 0.540337 (-0.064408) | 0.654412 / 1.386936 (-0.732524) |

</details>
</details>

![](https://cml.dev/watermark.png#42fdfbd567674d075c3a9148ec3c95221eb62cfe "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) | 0.007500 / 0.011353 (-0.003853) | 0.004328 / 0.011008 (-0.006681) | 0.086718 / 0.038508 (0.048209) | 0.098638 / 0.023109 (0.075529) | 0.335308 / 0.275898 (0.059409) | 0.369163 / 0.323480 (0.045683) | 0.005733 / 0.007986 (-0.002253) | 0.003738 / 0.004328 (-0.000590) | 0.066452 / 0.004250 (0.062202) | 0.066245 / 0.037052 (0.029192) | 0.337609 / 0.258489 (0.079120) | 0.388584 / 0.293841 (0.094744) | 0.031742 / 0.128546 (-0.096804) | 0.008721 / 0.075646 (-0.066925) | 0.290820 / 0.419271 (-0.128452) | 0.053323 / 0.043533 (0.009790) | 0.329192 / 0.255139 (0.074053) | 0.350560 / 0.283200 (0.067360) | 0.025402 / 0.141683 (-0.116281) | 1.476174 / 1.452155 (0.024020) | 1.578194 / 1.492716 (0.085478) |

### 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) | 0.256160 / 0.018006 (0.238154) | 0.560315 / 0.000490 (0.559825) | 0.005287 / 0.000200 (0.005088) | 0.000094 / 0.000054 (0.000040) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.029164 / 0.037411 (-0.008247) | 0.084881 / 0.014526 (0.070356) | 0.100979 / 0.176557 (-0.075577) | 0.156539 / 0.737135 (-0.580597) | 0.101510 / 0.296338 (-0.194828) |

### 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) | 0.381138 / 0.215209 (0.165929) | 3.791573 / 2.077655 (1.713918) | 1.841954 / 1.504120 (0.337834) | 1.672463 / 1.541195 (0.131268) | 1.785769 / 1.468490 (0.317279) | 0.483263 / 4.584777 (-4.101514) | 3.617391 / 3.745712 (-0.128322) | 5.607794 / 5.269862 (0.337933) | 3.359530 / 4.565676 (-1.206147) | 0.056826 / 0.424275 (-0.367449) | 0.007375 / 0.007607 (-0.000232) | 0.455853 / 0.226044 (0.229809) | 4.548965 / 2.268929 (2.280037) | 2.412716 / 55.444624 (-53.031908) | 1.991456 / 6.876477 (-4.885021) | 2.242851 / 2.142072 (0.100778) | 0.573070 / 4.805227 (-4.232157) | 0.134658 / 6.500664 (-6.366006) | 0.061539 / 0.075469 (-0.013930) |

### 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) | 1.278306 / 1.841788 (-0.563481) | 20.634317 / 8.074308 (12.560009) | 15.164246 / 10.191392 (4.972854) | 0.167487 / 0.680424 (-0.512937) | 0.019006 / 0.534201 (-0.515195) | 0.394617 / 0.579283 (-0.184666) | 0.423385 / 0.434364 (-0.010979) | 0.469968 / 0.540337 (-0.070370) | 0.630058 / 1.386936 (-0.756878) |

</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) | 0.006793 / 0.011353 (-0.004559) | 0.004260 / 0.011008 (-0.006748) | 0.065398 / 0.038508 (0.026890) | 0.077850 / 0.023109 (0.054741) | 0.371754 / 0.275898 (0.095855) | 0.400652 / 0.323480 (0.077172) | 0.005729 / 0.007986 (-0.002256) | 0.003660 / 0.004328 (-0.000669) | 0.065119 / 0.004250 (0.060869) | 0.060714 / 0.037052 (0.023661) | 0.384592 / 0.258489 (0.126103) | 0.412806 / 0.293841 (0.118965) | 0.031865 / 0.128546 (-0.096681) | 0.008807 / 0.075646 (-0.066839) | 0.071156 / 0.419271 (-0.348115) | 0.049571 / 0.043533 (0.006038) | 0.367381 / 0.255139 (0.112242) | 0.386713 / 0.283200 (0.103513) | 0.024838 / 0.141683 (-0.116845) | 1.492986 / 1.452155 (0.040831) | 1.559243 / 1.492716 (0.066526) |

### 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) | 0.269737 / 0.018006 (0.251730) | 0.565177 / 0.000490 (0.564687) | 0.000404 / 0.000200 (0.000204) | 0.000060 / 0.000054 (0.000006) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.031631 / 0.037411 (-0.005780) | 0.087289 / 0.014526 (0.072764) | 0.102798 / 0.176557 (-0.073759) | 0.158977 / 0.737135 (-0.578158) | 0.105495 / 0.296338 (-0.190843) |

### 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) | 0.425067 / 0.215209 (0.209858) | 4.243121 / 2.077655 (2.165466) | 2.234567 / 1.504120 (0.730447) | 2.070810 / 1.541195 (0.529615) | 2.176802 / 1.468490 (0.708312) | 0.484987 / 4.584777 (-4.099790) | 3.647000 / 3.745712 (-0.098712) | 3.574843 / 5.269862 (-1.695019) | 2.092581 / 4.565676 (-2.473095) | 0.057299 / 0.424275 (-0.366976) | 0.007480 / 0.007607 (-0.000128) | 0.507838 / 0.226044 (0.281794) | 5.076594 / 2.268929 (2.807666) | 2.718858 / 55.444624 (-52.725766) | 2.362793 / 6.876477 (-4.513684) | 2.451962 / 2.142072 (0.309890) | 0.581355 / 4.805227 (-4.223872) | 0.133723 / 6.500664 (-6.366941) | 0.061896 / 0.075469 (-0.013573) |

### 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) | 1.325814 / 1.841788 (-0.515974) | 20.614502 / 8.074308 (12.540194) | 14.769422 / 10.191392 (4.578029) | 0.193797 / 0.680424 (-0.486627) | 0.018379 / 0.534201 (-0.515822) | 0.394153 / 0.579283 (-0.185130) | 0.409585 / 0.434364 (-0.024779) | 0.479107 / 0.540337 (-0.061231) | 0.668397 / 1.386936 (-0.718539) |

</details>
</details>

![](https://cml.dev/watermark.png#b2d892237169bad5512c91cae453d257ebefc201 "CML watermark")
In the end, I decided to remove the progress bar to avoid having it displayed when loading a cached dataset.<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) | 0.006673 / 0.011353 (-0.004680) | 0.004162 / 0.011008 (-0.006846) | 0.084017 / 0.038508 (0.045509) | 0.079536 / 0.023109 (0.056426) | 0.313594 / 0.275898 (0.037695) | 0.349200 / 0.323480 (0.025720) | 0.005544 / 0.007986 (-0.002441) | 0.003472 / 0.004328 (-0.000857) | 0.064742 / 0.004250 (0.060491) | 0.056857 / 0.037052 (0.019805) | 0.318635 / 0.258489 (0.060146) | 0.354378 / 0.293841 (0.060537) | 0.030856 / 0.128546 (-0.097690) | 0.008759 / 0.075646 (-0.066887) | 0.287760 / 0.419271 (-0.131511) | 0.052307 / 0.043533 (0.008775) | 0.316396 / 0.255139 (0.061257) | 0.351408 / 0.283200 (0.068208) | 0.024914 / 0.141683 (-0.116769) | 1.484592 / 1.452155 (0.032437) | 1.560662 / 1.492716 (0.067945) |

### 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) | 0.280938 / 0.018006 (0.262932) | 0.580236 / 0.000490 (0.579747) | 0.003369 / 0.000200 (0.003169) | 0.000090 / 0.000054 (0.000036) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.028736 / 0.037411 (-0.008675) | 0.082916 / 0.014526 (0.068390) | 0.097761 / 0.176557 (-0.078796) | 0.153515 / 0.737135 (-0.583620) | 0.099282 / 0.296338 (-0.197057) |

### 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) | 0.401244 / 0.215209 (0.186035) | 4.019866 / 2.077655 (1.942211) | 2.029642 / 1.504120 (0.525522) | 1.849591 / 1.541195 (0.308396) | 1.946829 / 1.468490 (0.478339) | 0.479750 / 4.584777 (-4.105027) | 3.482822 / 3.745712 (-0.262890) | 3.955859 / 5.269862 (-1.314003) | 2.370747 / 4.565676 (-2.194930) | 0.056905 / 0.424275 (-0.367370) | 0.007319 / 0.007607 (-0.000288) | 0.485310 / 0.226044 (0.259266) | 4.858228 / 2.268929 (2.589299) | 2.500476 / 55.444624 (-52.944148) | 2.171156 / 6.876477 (-4.705320) | 2.427266 / 2.142072 (0.285194) | 0.570199 / 4.805227 (-4.235029) | 0.130855 / 6.500664 (-6.369809) | 0.060269 / 0.075469 (-0.015200) |

### 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) | 1.258044 / 1.841788 (-0.583743) | 20.218657 / 8.074308 (12.144349) | 13.597970 / 10.191392 (3.406578) | 0.167656 / 0.680424 (-0.512768) | 0.018137 / 0.534201 (-0.516064) | 0.395309 / 0.579283 (-0.183975) | 0.406325 / 0.434364 (-0.028039) | 0.467457 / 0.540337 (-0.072880) | 0.613636 / 1.386936 (-0.773300) |

</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) | 0.006846 / 0.011353 (-0.004507) | 0.004207 / 0.011008 (-0.006802) | 0.064525 / 0.038508 (0.026017) | 0.081329 / 0.023109 (0.058220) | 0.399838 / 0.275898 (0.123940) | 0.431305 / 0.323480 (0.107825) | 0.005859 / 0.007986 (-0.002127) | 0.003568 / 0.004328 (-0.000760) | 0.065262 / 0.004250 (0.061011) | 0.064796 / 0.037052 (0.027744) | 0.406858 / 0.258489 (0.148369) | 0.440971 / 0.293841 (0.147130) | 0.031421 / 0.128546 (-0.097125) | 0.008777 / 0.075646 (-0.066870) | 0.071418 / 0.419271 (-0.347853) | 0.049263 / 0.043533 (0.005730) | 0.384279 / 0.255139 (0.129140) | 0.410745 / 0.283200 (0.127546) | 0.024467 / 0.141683 (-0.117216) | 1.522379 / 1.452155 (0.070224) | 1.581636 / 1.492716 (0.088920) |

### 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) | 0.276161 / 0.018006 (0.258155) | 0.548842 / 0.000490 (0.548352) | 0.004523 / 0.000200 (0.004324) | 0.000098 / 0.000054 (0.000043) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.030747 / 0.037411 (-0.006664) | 0.087493 / 0.014526 (0.072967) | 0.106563 / 0.176557 (-0.069993) | 0.162949 / 0.737135 (-0.574186) | 0.105303 / 0.296338 (-0.191036) |

### 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) | 0.425854 / 0.215209 (0.210645) | 4.244797 / 2.077655 (2.167142) | 2.269006 / 1.504120 (0.764886) | 2.097428 / 1.541195 (0.556234) | 2.181038 / 1.468490 (0.712548) | 0.477286 / 4.584777 (-4.107491) | 3.591452 / 3.745712 (-0.154260) | 3.481281 / 5.269862 (-1.788580) | 2.066895 / 4.565676 (-2.498782) | 0.056576 / 0.424275 (-0.367699) | 0.007409 / 0.007607 (-0.000199) | 0.498411 / 0.226044 (0.272367) | 4.994873 / 2.268929 (2.725945) | 2.749148 / 55.444624 (-52.695476) | 2.378544 / 6.876477 (-4.497932) | 2.452859 / 2.142072 (0.310786) | 0.571340 / 4.805227 (-4.233887) | 0.132174 / 6.500664 (-6.368490) | 0.061507 / 0.075469 (-0.013962) |

### 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) | 1.370773 / 1.841788 (-0.471015) | 20.493342 / 8.074308 (12.419034) | 14.809886 / 10.191392 (4.618494) | 0.175730 / 0.680424 (-0.504693) | 0.018617 / 0.534201 (-0.515583) | 0.393808 / 0.579283 (-0.185476) | 0.416419 / 0.434364 (-0.017945) | 0.477183 / 0.540337 (-0.063155) | 0.668060 / 1.386936 (-0.718876) |

</details>
</details>

![](https://cml.dev/watermark.png#2de7a2a4af5d94b0f98a7a6db94e78984af40602 "CML watermark")
Nice one :)