test_astype portion of #19627
parametrized as suggested
# [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/19637?src=pr&el=h1) Report
> Merging [#19637](https://codecov.io/gh/pandas-dev/pandas/pull/19637?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/13bd008edbbe0780600072d404fa989accb5e762?src=pr&el=desc) will **not change** coverage.
> The diff coverage is `n/a`.

[![Impacted file tree graph](https://codecov.io/gh/pandas-dev/pandas/pull/19637/graphs/tree.svg?token=eZ4WkYLtcO&width=650&height=150&src=pr)](https://codecov.io/gh/pandas-dev/pandas/pull/19637?src=pr&el=tree)

```diff
@@           Coverage Diff           @@
##           master   #19637   +/-   ##
=======================================
  Coverage   91.61%   91.61%           
=======================================
  Files         150      150           
  Lines       48807    48807           
=======================================
  Hits        44716    44716           
  Misses       4091     4091
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `89.99% <ø> (ø)` | :arrow_up: |
| #single | `41.73% <ø> (ø)` | :arrow_up: |


------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/19637?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/19637?src=pr&el=footer). Last update [13bd008...1a833b0](https://codecov.io/gh/pandas-dev/pandas/pull/19637?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).
 thanks!