Continued ujson cleanups
State: closed

ref some of the comments by @jbrockmendel in #26212



Labels:
name: IO JSON
description: read_json, to_json, json_normalize
name: Clean

Comments:
# [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/26222?src=pr&el=h1) Report
> Merging [#26222](https://codecov.io/gh/pandas-dev/pandas/pull/26222?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/65466f04025474c3ee1bd2f4e49a1c5e24b76f7b?src=pr&el=desc) will **decrease** coverage by `<.01%`.
> The diff coverage is `n/a`.

[![Impacted file tree graph](https://codecov.io/gh/pandas-dev/pandas/pull/26222/graphs/tree.svg?width=650&token=eZ4WkYLtcO&height=150&src=pr)](https://codecov.io/gh/pandas-dev/pandas/pull/26222?src=pr&el=tree)

```diff
@@            Coverage Diff             @@
##           master   #26222      +/-   ##
==========================================
- Coverage   91.97%   91.97%   -0.01%     
==========================================
  Files         175      175              
  Lines       52379    52379              
==========================================
- Hits        48178    48174       -4     
- Misses       4201     4205       +4
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `90.52% <ø> (ø)` | :arrow_up: |
| #single | `40.7% <ø> (-0.15%)` | :arrow_down: |

| [Impacted Files](https://codecov.io/gh/pandas-dev/pandas/pull/26222?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [pandas/io/gbq.py](https://codecov.io/gh/pandas-dev/pandas/pull/26222/diff?src=pr&el=tree#diff-cGFuZGFzL2lvL2dicS5weQ==) | `78.94% <0%> (-10.53%)` | :arrow_down: |
| [pandas/core/frame.py](https://codecov.io/gh/pandas-dev/pandas/pull/26222/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvZnJhbWUucHk=) | `96.9% <0%> (-0.12%)` | :arrow_down: |

------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/26222?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/26222?src=pr&el=footer). Last update [65466f0...2f478f9](https://codecov.io/gh/pandas-dev/pandas/pull/26222?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/26222?src=pr&el=h1) Report
> Merging [#26222](https://codecov.io/gh/pandas-dev/pandas/pull/26222?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/65466f04025474c3ee1bd2f4e49a1c5e24b76f7b?src=pr&el=desc) will **decrease** coverage by `<.01%`.
> The diff coverage is `n/a`.

[![Impacted file tree graph](https://codecov.io/gh/pandas-dev/pandas/pull/26222/graphs/tree.svg?width=650&token=eZ4WkYLtcO&height=150&src=pr)](https://codecov.io/gh/pandas-dev/pandas/pull/26222?src=pr&el=tree)

```diff
@@            Coverage Diff             @@
##           master   #26222      +/-   ##
==========================================
- Coverage   91.97%   91.97%   -0.01%     
==========================================
  Files         175      175              
  Lines       52379    52379              
==========================================
- Hits        48178    48174       -4     
- Misses       4201     4205       +4
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `90.52% <ø> (ø)` | :arrow_up: |
| #single | `40.7% <ø> (-0.15%)` | :arrow_down: |

| [Impacted Files](https://codecov.io/gh/pandas-dev/pandas/pull/26222?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [pandas/io/gbq.py](https://codecov.io/gh/pandas-dev/pandas/pull/26222/diff?src=pr&el=tree#diff-cGFuZGFzL2lvL2dicS5weQ==) | `78.94% <0%> (-10.53%)` | :arrow_down: |
| [pandas/core/frame.py](https://codecov.io/gh/pandas-dev/pandas/pull/26222/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvZnJhbWUucHk=) | `96.9% <0%> (-0.12%)` | :arrow_down: |

------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/26222?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/26222?src=pr&el=footer). Last update [65466f0...2f478f9](https://codecov.io/gh/pandas-dev/pandas/pull/26222?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).

All of the decimal tests are located here:

https://github.com/pandas-dev/pandas/blob/51980fe369f75e827143f21b6b26e0d6a86c8c78/pandas/tests/io/json/test_ujson.py#L62

They don't appear in anything user-facing but are covered in the encode/decode round tripping that this would effect.

If Decimal subclasses are a concern can also parametrize that test for Decimal and an arbitrary subclass. Let me know.
thanks @WillAyd