#25790 Updating type hints to Python3 syntax in pandas/core/array
- [x] addresses the other half of #25790
- [x] pandas/tests/arrays/ tests passed
- [x] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`
# [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/25829?src=pr&el=h1) Report
> Merging [#25829](https://codecov.io/gh/pandas-dev/pandas/pull/25829?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/e31b4f46df6ab1182c16183f48df76fb4beaca0f?src=pr&el=desc) will **decrease** coverage by `<.01%`.
> The diff coverage is `97.36%`.

[![Impacted file tree graph](https://codecov.io/gh/pandas-dev/pandas/pull/25829/graphs/tree.svg?width=650&token=eZ4WkYLtcO&height=150&src=pr)](https://codecov.io/gh/pandas-dev/pandas/pull/25829?src=pr&el=tree)

```diff
@@            Coverage Diff             @@
##           master   #25829      +/-   ##
==========================================
- Coverage   91.27%   91.27%   -0.01%     
==========================================
  Files         173      173              
  Lines       53002    53017      +15     
==========================================
+ Hits        48376    48389      +13     
- Misses       4626     4628       +2
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `89.83% <97.36%> (ø)` | :arrow_up: |
| #single | `41.78% <97.36%> (+0.02%)` | :arrow_up: |

| [Impacted Files](https://codecov.io/gh/pandas-dev/pandas/pull/25829?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [pandas/core/arrays/base.py](https://codecov.io/gh/pandas-dev/pandas/pull/25829/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvYXJyYXlzL2Jhc2UucHk=) | `98.33% <100%> (+0.05%)` | :arrow_up: |
| [pandas/core/arrays/datetimelike.py](https://codecov.io/gh/pandas-dev/pandas/pull/25829/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvYXJyYXlzL2RhdGV0aW1lbGlrZS5weQ==) | `97.69% <100%> (+0.01%)` | :arrow_up: |
| [pandas/core/arrays/integer.py](https://codecov.io/gh/pandas-dev/pandas/pull/25829/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvYXJyYXlzL2ludGVnZXIucHk=) | `96.33% <100%> (+0.01%)` | :arrow_up: |
| [pandas/core/arrays/period.py](https://codecov.io/gh/pandas-dev/pandas/pull/25829/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvYXJyYXlzL3BlcmlvZC5weQ==) | `98.53% <100%> (ø)` | :arrow_up: |
| [pandas/core/arrays/sparse.py](https://codecov.io/gh/pandas-dev/pandas/pull/25829/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvYXJyYXlzL3NwYXJzZS5weQ==) | `92.19% <100%> (ø)` | :arrow_up: |
| [pandas/core/arrays/datetimes.py](https://codecov.io/gh/pandas-dev/pandas/pull/25829/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvYXJyYXlzL2RhdGV0aW1lcy5weQ==) | `97.8% <100%> (ø)` | :arrow_up: |
| [pandas/core/arrays/array\_.py](https://codecov.io/gh/pandas-dev/pandas/pull/25829/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvYXJyYXlzL2FycmF5Xy5weQ==) | `97.87% <75%> (-2.13%)` | :arrow_down: |
| [pandas/util/testing.py](https://codecov.io/gh/pandas-dev/pandas/pull/25829/diff?src=pr&el=tree#diff-cGFuZGFzL3V0aWwvdGVzdGluZy5weQ==) | `89.3% <0%> (-0.11%)` | :arrow_down: |

------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/25829?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/25829?src=pr&el=footer). Last update [e31b4f4...ea9c2b3](https://codecov.io/gh/pandas-dev/pandas/pull/25829?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/25829?src=pr&el=h1) Report
> Merging [#25829](https://codecov.io/gh/pandas-dev/pandas/pull/25829?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/882961df6025b800b899d351c243412e799accf4?src=pr&el=desc) will **increase** coverage by `0.02%`.
> The diff coverage is `100%`.

[![Impacted file tree graph](https://codecov.io/gh/pandas-dev/pandas/pull/25829/graphs/tree.svg?width=650&token=eZ4WkYLtcO&height=150&src=pr)](https://codecov.io/gh/pandas-dev/pandas/pull/25829?src=pr&el=tree)

```diff
@@            Coverage Diff             @@
##           master   #25829      +/-   ##
==========================================
+ Coverage   91.53%   91.56%   +0.02%     
==========================================
  Files         175      175              
  Lines       52808    52789      -19     
==========================================
- Hits        48338    48335       -3     
+ Misses       4470     4454      -16
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `90.12% <100%> (+0.02%)` | :arrow_up: |
| #single | `41.83% <100%> (ø)` | :arrow_up: |

| [Impacted Files](https://codecov.io/gh/pandas-dev/pandas/pull/25829?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [pandas/core/arrays/datetimes.py](https://codecov.io/gh/pandas-dev/pandas/pull/25829/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvYXJyYXlzL2RhdGV0aW1lcy5weQ==) | `97.8% <ø> (ø)` | :arrow_up: |
| [pandas/core/arrays/base.py](https://codecov.io/gh/pandas-dev/pandas/pull/25829/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvYXJyYXlzL2Jhc2UucHk=) | `98.33% <100%> (+0.05%)` | :arrow_up: |
| [pandas/core/arrays/datetimelike.py](https://codecov.io/gh/pandas-dev/pandas/pull/25829/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvYXJyYXlzL2RhdGV0aW1lbGlrZS5weQ==) | `97.69% <100%> (+0.01%)` | :arrow_up: |
| [pandas/core/arrays/integer.py](https://codecov.io/gh/pandas-dev/pandas/pull/25829/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvYXJyYXlzL2ludGVnZXIucHk=) | `96.33% <100%> (+0.01%)` | :arrow_up: |
| [pandas/core/arrays/period.py](https://codecov.io/gh/pandas-dev/pandas/pull/25829/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvYXJyYXlzL3BlcmlvZC5weQ==) | `98.53% <100%> (ø)` | :arrow_up: |
| [pandas/core/arrays/sparse.py](https://codecov.io/gh/pandas-dev/pandas/pull/25829/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvYXJyYXlzL3NwYXJzZS5weQ==) | `92.18% <100%> (ø)` | :arrow_up: |
| [pandas/core/arrays/array\_.py](https://codecov.io/gh/pandas-dev/pandas/pull/25829/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvYXJyYXlzL2FycmF5Xy5weQ==) | `100% <100%> (ø)` | :arrow_up: |
| [pandas/compat/pickle\_compat.py](https://codecov.io/gh/pandas-dev/pandas/pull/25829/diff?src=pr&el=tree#diff-cGFuZGFzL2NvbXBhdC9waWNrbGVfY29tcGF0LnB5) | `69.51% <0%> (-6.1%)` | :arrow_down: |
| [pandas/plotting/\_compat.py](https://codecov.io/gh/pandas-dev/pandas/pull/25829/diff?src=pr&el=tree#diff-cGFuZGFzL3Bsb3R0aW5nL19jb21wYXQucHk=) | `83.33% <0%> (-3.34%)` | :arrow_down: |
| [pandas/compat/numpy/\_\_init\_\_.py](https://codecov.io/gh/pandas-dev/pandas/pull/25829/diff?src=pr&el=tree#diff-cGFuZGFzL2NvbXBhdC9udW1weS9fX2luaXRfXy5weQ==) | `93.1% <0%> (-0.23%)` | :arrow_down: |
| ... and [10 more](https://codecov.io/gh/pandas-dev/pandas/pull/25829/diff?src=pr&el=tree-more) | |

------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/25829?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/25829?src=pr&el=footer). Last update [882961d...23aba8a](https://codecov.io/gh/pandas-dev/pandas/pull/25829?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).
 lgtm. @WillAyd merge when ready nice job @gwrome - thanks for helping to kick off these typing initiatives