Fix JSON builder when missing keys in first row 
NONE
_The documentation is not available anymore as the PR was closed or merged._
2023-04-19T14:37:09Z
https://github.com/huggingface/datasets/pull/5772#issuecomment-1514853819
https://api.github.com/repos/huggingface/datasets/issues/5772
IC_kwDODunzps5aStW7
https://api.github.com/repos/huggingface/datasets/issues/comments/1514853819/reactions
2023-04-21T06:38:47Z
https://api.github.com/repos/huggingface/datasets/issues/comments/1514853819
https://avatars.githubusercontent.com/u/99929124?v=4
https://api.github.com/users/HuggingFaceDocBuilderDev/events{/privacy}
https://api.github.com/users/HuggingFaceDocBuilderDev/followers
https://api.github.com/users/HuggingFaceDocBuilderDev/following{/other_user}
https://api.github.com/users/HuggingFaceDocBuilderDev/gists{/gist_id}
https://github.com/HuggingFaceDocBuilderDev
HuggingFaceDocBuilderDev
U_kgDOBfTMJA
https://api.github.com/users/HuggingFaceDocBuilderDev/orgs
https://api.github.com/users/HuggingFaceDocBuilderDev/received_events
https://api.github.com/users/HuggingFaceDocBuilderDev/repos
https://api.github.com/users/HuggingFaceDocBuilderDev/starred{/owner}{/repo}
https://api.github.com/users/HuggingFaceDocBuilderDev/subscriptions
User
https://api.github.com/users/HuggingFaceDocBuilderDev
public
NONE
<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) | 0.009262 / 0.011353 (-0.002091) | 0.006157 / 0.011008 (-0.004851) | 0.125960 / 0.038508 (0.087451) | 0.036213 / 0.023109 (0.013104) | 0.399331 / 0.275898 (0.123433) | 0.453597 / 0.323480 (0.130117) | 0.006990 / 0.007986 (-0.000995) | 0.007320 / 0.004328 (0.002991) | 0.100321 / 0.004250 (0.096070) | 0.048870 / 0.037052 (0.011818) | 0.396284 / 0.258489 (0.137795) | 0.475619 / 0.293841 (0.181778) | 0.052329 / 0.128546 (-0.076217) | 0.019564 / 0.075646 (-0.056083) | 0.430942 / 0.419271 (0.011670) | 0.063224 / 0.043533 (0.019692) | 0.391717 / 0.255139 (0.136578) | 0.448342 / 0.283200 (0.165142) | 0.114055 / 0.141683 (-0.027628) | 1.793204 / 1.452155 (0.341049) | 1.895151 / 1.492716 (0.402435) |

### 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) | 0.283699 / 0.018006 (0.265693) | 0.597194 / 0.000490 (0.596704) | 0.007143 / 0.000200 (0.006944) | 0.000602 / 0.000054 (0.000548) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.034761 / 0.037411 (-0.002651) | 0.124555 / 0.014526 (0.110030) | 0.149126 / 0.176557 (-0.027430) | 0.220335 / 0.737135 (-0.516801) | 0.153109 / 0.296338 (-0.143229) |

### 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) | 0.620210 / 0.215209 (0.405001) | 6.229937 / 2.077655 (4.152282) | 2.615203 / 1.504120 (1.111083) | 2.239337 / 1.541195 (0.698143) | 2.262138 / 1.468490 (0.793648) | 1.196498 / 4.584777 (-3.388279) | 5.609932 / 3.745712 (1.864220) | 3.031347 / 5.269862 (-2.238515) | 2.025530 / 4.565676 (-2.540146) | 0.139828 / 0.424275 (-0.284447) | 0.015476 / 0.007607 (0.007869) | 0.768964 / 0.226044 (0.542920) | 7.728677 / 2.268929 (5.459748) | 3.336407 / 55.444624 (-52.108217) | 2.700055 / 6.876477 (-4.176422) | 2.765223 / 2.142072 (0.623151) | 1.409073 / 4.805227 (-3.396155) | 0.246849 / 6.500664 (-6.253815) | 0.081231 / 0.075469 (0.005762) |

### 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) | 1.593836 / 1.841788 (-0.247952) | 18.020525 / 8.074308 (9.946216) | 21.766822 / 10.191392 (11.575430) | 0.258615 / 0.680424 (-0.421809) | 0.026895 / 0.534201 (-0.507306) | 0.529823 / 0.579283 (-0.049460) | 0.623470 / 0.434364 (0.189106) | 0.628171 / 0.540337 (0.087833) | 0.745249 / 1.386936 (-0.641687) |

</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) | 0.008624 / 0.011353 (-0.002729) | 0.006317 / 0.011008 (-0.004691) | 0.097315 / 0.038508 (0.058807) | 0.035217 / 0.023109 (0.012108) | 0.440197 / 0.275898 (0.164299) | 0.473863 / 0.323480 (0.150383) | 0.006722 / 0.007986 (-0.001264) | 0.006444 / 0.004328 (0.002116) | 0.102056 / 0.004250 (0.097806) | 0.047142 / 0.037052 (0.010089) | 0.452476 / 0.258489 (0.193986) | 0.487619 / 0.293841 (0.193778) | 0.052456 / 0.128546 (-0.076090) | 0.018735 / 0.075646 (-0.056911) | 0.114656 / 0.419271 (-0.304616) | 0.062577 / 0.043533 (0.019044) | 0.444471 / 0.255139 (0.189332) | 0.494264 / 0.283200 (0.211065) | 0.117112 / 0.141683 (-0.024571) | 1.848965 / 1.452155 (0.396810) | 1.984008 / 1.492716 (0.491292) |

### 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) | 0.290494 / 0.018006 (0.272488) | 0.588415 / 0.000490 (0.587925) | 0.000459 / 0.000200 (0.000259) | 0.000080 / 0.000054 (0.000026) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.032873 / 0.037411 (-0.004538) | 0.131139 / 0.014526 (0.116614) | 0.140268 / 0.176557 (-0.036289) | 0.204561 / 0.737135 (-0.532574) | 0.147443 / 0.296338 (-0.148895) |

### 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) | 0.636899 / 0.215209 (0.421690) | 6.236139 / 2.077655 (4.158484) | 2.801468 / 1.504120 (1.297348) | 2.398808 / 1.541195 (0.857613) | 2.493150 / 1.468490 (1.024659) | 1.228845 / 4.584777 (-3.355932) | 5.675874 / 3.745712 (1.930162) | 3.084939 / 5.269862 (-2.184922) | 2.061310 / 4.565676 (-2.504367) | 0.142285 / 0.424275 (-0.281990) | 0.014972 / 0.007607 (0.007365) | 0.786599 / 0.226044 (0.560555) | 7.876036 / 2.268929 (5.607107) | 3.476136 / 55.444624 (-51.968489) | 2.847922 / 6.876477 (-4.028555) | 3.040326 / 2.142072 (0.898253) | 1.448538 / 4.805227 (-3.356690) | 0.257230 / 6.500664 (-6.243434) | 0.085137 / 0.075469 (0.009668) |

### 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) | 1.668173 / 1.841788 (-0.173615) | 18.668520 / 8.074308 (10.594212) | 20.535542 / 10.191392 (10.344150) | 0.244580 / 0.680424 (-0.435844) | 0.026364 / 0.534201 (-0.507837) | 0.531753 / 0.579283 (-0.047530) | 0.616578 / 0.434364 (0.182214) | 0.618906 / 0.540337 (0.078569) | 0.738785 / 1.386936 (-0.648151) |

</details>
</details>

![](https://cml.dev/watermark.png#f7265cafa3103d77d6d52aa897088faefcd96659 "CML watermark")

2023-04-21T06:45:12Z
https://github.com/huggingface/datasets/pull/5772#issuecomment-1517344864
https://api.github.com/repos/huggingface/datasets/issues/5772
IC_kwDODunzps5acNhg
https://api.github.com/repos/huggingface/datasets/issues/comments/1517344864/reactions
2023-04-21T06:45:12Z
https://api.github.com/repos/huggingface/datasets/issues/comments/1517344864
https://avatars.githubusercontent.com/in/15368?v=4
https://api.github.com/users/github-actions%5Bbot%5D/events{/privacy}
https://api.github.com/users/github-actions%5Bbot%5D/followers
https://api.github.com/users/github-actions%5Bbot%5D/following{/other_user}
https://api.github.com/users/github-actions%5Bbot%5D/gists{/gist_id}
https://github.com/apps/github-actions
github-actions[bot]
MDM6Qm90NDE4OTgyODI=
https://api.github.com/users/github-actions%5Bbot%5D/orgs
https://api.github.com/users/github-actions%5Bbot%5D/received_events
https://api.github.com/users/github-actions%5Bbot%5D/repos
https://api.github.com/users/github-actions%5Bbot%5D/starred{/owner}{/repo}
https://api.github.com/users/github-actions%5Bbot%5D/subscriptions
Bot
https://api.github.com/users/github-actions%5Bbot%5D
public
Until now, the JSON builder only considered the keys present in the first element of the list:
- Either explicitly: by passing index 0 in `dataset[0].keys()`
- Or implicitly: `pa.Table.from_pylist(dataset)`, where "schema (default None): If not passed, will be inferred from the first row of the mapping values"

This PR fixes the bug by considering the union of the keys present in all the rows.


Fix #5726.