Fixed issue with read_json and partially missing MI names
State: closed

- [X] closes #19130
- [X] tests added / passed
- [X] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`
- [ ] whatsnew entry


Labels:
name: Indexing
description: Related to indexing on series/frames, not to indexes themselves
name: IO JSON
description: read_json, to_json, json_normalize
name: MultiIndex

Comments:
# [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/19177?src=pr&el=h1) Report
> Merging [#19177](https://codecov.io/gh/pandas-dev/pandas/pull/19177?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/8347ff8c9d8876fa46f73dbc48919a672caef1d2?src=pr&el=desc) will **decrease** coverage by `<.01%`.
> The diff coverage is `100%`.

[![Impacted file tree graph](https://codecov.io/gh/pandas-dev/pandas/pull/19177/graphs/tree.svg?token=eZ4WkYLtcO&width=650&src=pr&height=150)](https://codecov.io/gh/pandas-dev/pandas/pull/19177?src=pr&el=tree)

```diff
@@            Coverage Diff             @@
##           master   #19177      +/-   ##
==========================================
- Coverage   91.53%   91.52%   -0.01%     
==========================================
  Files         147      148       +1     
  Lines       48797    48784      -13     
==========================================
- Hits        44664    44648      -16     
- Misses       4133     4136       +3
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `89.89% <100%> (-0.01%)` | :arrow_down: |
| #single | `41.6% <10%> (ø)` | :arrow_up: |

| [Impacted Files](https://codecov.io/gh/pandas-dev/pandas/pull/19177?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [pandas/io/json/json.py](https://codecov.io/gh/pandas-dev/pandas/pull/19177/diff?src=pr&el=tree#diff-cGFuZGFzL2lvL2pzb24vanNvbi5weQ==) | `92.6% <ø> (ø)` | :arrow_up: |
| [pandas/io/json/table\_schema.py](https://codecov.io/gh/pandas-dev/pandas/pull/19177/diff?src=pr&el=tree#diff-cGFuZGFzL2lvL2pzb24vdGFibGVfc2NoZW1hLnB5) | `98.29% <100%> (+0.09%)` | :arrow_up: |
| [pandas/core/dtypes/cast.py](https://codecov.io/gh/pandas-dev/pandas/pull/19177/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvZHR5cGVzL2Nhc3QucHk=) | `88.42% <0%> (-0.24%)` | :arrow_down: |
| [pandas/core/ops.py](https://codecov.io/gh/pandas-dev/pandas/pull/19177/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvb3BzLnB5) | `91.89% <0%> (-0.18%)` | :arrow_down: |
| [pandas/core/indexes/interval.py](https://codecov.io/gh/pandas-dev/pandas/pull/19177/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvaW5kZXhlcy9pbnRlcnZhbC5weQ==) | `92.19% <0%> (-0.11%)` | :arrow_down: |
| [pandas/core/internals.py](https://codecov.io/gh/pandas-dev/pandas/pull/19177/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvaW50ZXJuYWxzLnB5) | `94.42% <0%> (-0.07%)` | :arrow_down: |
| [pandas/tseries/offsets.py](https://codecov.io/gh/pandas-dev/pandas/pull/19177/diff?src=pr&el=tree#diff-cGFuZGFzL3RzZXJpZXMvb2Zmc2V0cy5weQ==) | `97.06% <0%> (-0.03%)` | :arrow_down: |
| [pandas/core/frame.py](https://codecov.io/gh/pandas-dev/pandas/pull/19177/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvZnJhbWUucHk=) | `97.62% <0%> (ø)` | :arrow_up: |
| [pandas/core/reshape/reshape.py](https://codecov.io/gh/pandas-dev/pandas/pull/19177/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvcmVzaGFwZS9yZXNoYXBlLnB5) | `100% <0%> (ø)` | :arrow_up: |
| [pandas/tools/hashing.py](https://codecov.io/gh/pandas-dev/pandas/pull/19177/diff?src=pr&el=tree#diff-cGFuZGFzL3Rvb2xzL2hhc2hpbmcucHk=) | `100% <0%> (ø)` | |
| ... and [1 more](https://codecov.io/gh/pandas-dev/pandas/pull/19177/diff?src=pr&el=tree-more) | |

------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/19177?src=pr&el=continue).
> **Legend** - [Click here to learn more](https://docs.codecov.io/docs/codecov-delta)
> `Δ = absolute <relative> (impact)`, `ø = not affected`, `? = missing data`
> Powered by [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/19177?src=pr&el=footer). Last update [8347ff8...1306b0e](https://codecov.io/gh/pandas-dev/pandas/pull/19177?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).

# [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/19177?src=pr&el=h1) Report
> Merging [#19177](https://codecov.io/gh/pandas-dev/pandas/pull/19177?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/787ab5556f23d2e10b798d2e58e66789d79fd4d5?src=pr&el=desc) will **decrease** coverage by `0.02%`.
> The diff coverage is `100%`.

[![Impacted file tree graph](https://codecov.io/gh/pandas-dev/pandas/pull/19177/graphs/tree.svg?src=pr&token=eZ4WkYLtcO&width=650&height=150)](https://codecov.io/gh/pandas-dev/pandas/pull/19177?src=pr&el=tree)

```diff
@@            Coverage Diff             @@
##           master   #19177      +/-   ##
==========================================
- Coverage   91.55%   91.53%   -0.03%     
==========================================
  Files         147      147              
  Lines       48812    48818       +6     
==========================================
- Hits        44690    44684       -6     
- Misses       4122     4134      +12
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `89.9% <100%> (-0.03%)` | :arrow_down: |
| #single | `41.7% <10%> (-0.01%)` | :arrow_down: |

| [Impacted Files](https://codecov.io/gh/pandas-dev/pandas/pull/19177?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [pandas/io/json/json.py](https://codecov.io/gh/pandas-dev/pandas/pull/19177/diff?src=pr&el=tree#diff-cGFuZGFzL2lvL2pzb24vanNvbi5weQ==) | `92.6% <ø> (ø)` | :arrow_up: |
| [pandas/io/json/table\_schema.py](https://codecov.io/gh/pandas-dev/pandas/pull/19177/diff?src=pr&el=tree#diff-cGFuZGFzL2lvL2pzb24vdGFibGVfc2NoZW1hLnB5) | `98.29% <100%> (+0.09%)` | :arrow_up: |
| [pandas/plotting/\_converter.py](https://codecov.io/gh/pandas-dev/pandas/pull/19177/diff?src=pr&el=tree#diff-cGFuZGFzL3Bsb3R0aW5nL19jb252ZXJ0ZXIucHk=) | `65.22% <0%> (-1.74%)` | :arrow_down: |

------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/19177?src=pr&el=continue).
> **Legend** - [Click here to learn more](https://docs.codecov.io/docs/codecov-delta)
> `Δ = absolute <relative> (impact)`, `ø = not affected`, `? = missing data`
> Powered by [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/19177?src=pr&el=footer). Last update [787ab55...3c9ff1d](https://codecov.io/gh/pandas-dev/pandas/pull/19177?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).

lgtm. just asking the question above.
thanks @WillAyd 

@TomAugspurger will open a new issue to discuss