BUG: TDI/PI comparison with zero-dim array
State: closed

- [x] closes #26689
- [x] tests added / passed
- [x] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`
- [x] whatsnew entry

The long-term solution to problems of this kind will be #23853.

Labels:
name: Bug
name: Timedelta
description: Timedelta data type
name: Period
description: Period data type

Comments:
# [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/26707?src=pr&el=h1) Report
> Merging [#26707](https://codecov.io/gh/pandas-dev/pandas/pull/26707?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/5b10e31fbf2707f354c2ffe287b434f10a8651d1?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/26707/graphs/tree.svg?width=650&token=eZ4WkYLtcO&height=150&src=pr)](https://codecov.io/gh/pandas-dev/pandas/pull/26707?src=pr&el=tree)

```diff
@@            Coverage Diff             @@
##           master   #26707      +/-   ##
==========================================
- Coverage   91.88%   91.88%   -0.01%     
==========================================
  Files         174      174              
  Lines       50699    50702       +3     
==========================================
- Hits        46587    46586       -1     
- Misses       4112     4116       +4
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `90.42% <100%> (ø)` | :arrow_up: |
| #single | `41.93% <66.66%> (-0.09%)` | :arrow_down: |

| [Impacted Files](https://codecov.io/gh/pandas-dev/pandas/pull/26707?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [pandas/core/arrays/period.py](https://codecov.io/gh/pandas-dev/pandas/pull/26707/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvYXJyYXlzL3BlcmlvZC5weQ==) | `98.54% <100%> (ø)` | :arrow_up: |
| [pandas/core/arrays/timedeltas.py](https://codecov.io/gh/pandas-dev/pandas/pull/26707/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvYXJyYXlzL3RpbWVkZWx0YXMucHk=) | `88.82% <100%> (+0.02%)` | :arrow_up: |
| [pandas/io/gbq.py](https://codecov.io/gh/pandas-dev/pandas/pull/26707/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/26707/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvZnJhbWUucHk=) | `97% <0%> (-0.12%)` | :arrow_down: |

------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/26707?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/26707?src=pr&el=footer). Last update [5b10e31...bab377d](https://codecov.io/gh/pandas-dev/pandas/pull/26707?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/26707?src=pr&el=h1) Report
> Merging [#26707](https://codecov.io/gh/pandas-dev/pandas/pull/26707?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/5b10e31fbf2707f354c2ffe287b434f10a8651d1?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/26707/graphs/tree.svg?width=650&token=eZ4WkYLtcO&height=150&src=pr)](https://codecov.io/gh/pandas-dev/pandas/pull/26707?src=pr&el=tree)

```diff
@@            Coverage Diff             @@
##           master   #26707      +/-   ##
==========================================
- Coverage   91.88%   91.88%   -0.01%     
==========================================
  Files         174      174              
  Lines       50699    50702       +3     
==========================================
- Hits        46587    46586       -1     
- Misses       4112     4116       +4
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `90.42% <100%> (ø)` | :arrow_up: |
| #single | `41.93% <66.66%> (-0.09%)` | :arrow_down: |

| [Impacted Files](https://codecov.io/gh/pandas-dev/pandas/pull/26707?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [pandas/core/arrays/period.py](https://codecov.io/gh/pandas-dev/pandas/pull/26707/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvYXJyYXlzL3BlcmlvZC5weQ==) | `98.54% <100%> (ø)` | :arrow_up: |
| [pandas/core/arrays/timedeltas.py](https://codecov.io/gh/pandas-dev/pandas/pull/26707/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvYXJyYXlzL3RpbWVkZWx0YXMucHk=) | `88.82% <100%> (+0.02%)` | :arrow_up: |
| [pandas/io/gbq.py](https://codecov.io/gh/pandas-dev/pandas/pull/26707/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/26707/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvZnJhbWUucHk=) | `97% <0%> (-0.12%)` | :arrow_down: |

------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/26707?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/26707?src=pr&el=footer). Last update [5b10e31...bab377d](https://codecov.io/gh/pandas-dev/pandas/pull/26707?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).

thanks @jbrockmendel nice to have your PRs again!