TST: GH18498 - Split test_pytables into sub-modules
- [x] closes #18498 
- [x] tests moved / passed
- [x] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`
- [ ] whatsnew entry

Moved test classes for pytables into sub-modules.
Moved hdf test data files needed into sub-module.

I did not change any tests, just broke up the classes into separate modules.
Hello @mikebarkas! Thanks for updating the PR.

 - In the file [`pandas/tests/io/pytables/common.py`](https://github.com/pandas-dev/pandas/blob/5052897495dc4b5a1e6dc45c2c716f93696d475e/pandas/tests/io/pytables/common.py), following are the PEP8 issues :

> [Line 67:9](https://github.com/pandas-dev/pandas/blob/5052897495dc4b5a1e6dc45c2c716f93696d475e/pandas/tests/io/pytables/common.py#L67): [E722](https://duckduckgo.com/?q=pep8%20E722) do not use bare except'
> [Line 75:5](https://github.com/pandas-dev/pandas/blob/5052897495dc4b5a1e6dc45c2c716f93696d475e/pandas/tests/io/pytables/common.py#L75): [E722](https://duckduckgo.com/?q=pep8%20E722) do not use bare except'
> [Line 84:5](https://github.com/pandas-dev/pandas/blob/5052897495dc4b5a1e6dc45c2c716f93696d475e/pandas/tests/io/pytables/common.py#L84): [E722](https://duckduckgo.com/?q=pep8%20E722) do not use bare except'

































##### Comment last updated on April 29, 2018 at 17:58 Hours UTC PEP8 issue for `common.py` 
`do not use bare except` This is in existing code.
This issue is for moving the tests and not changing test.  # [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/19735?src=pr&el=h1) Report
> Merging [#19735](https://codecov.io/gh/pandas-dev/pandas/pull/19735?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/cdfce2b0ad99f7faad57cc5247cf33aab5725bed?src=pr&el=desc) will **decrease** coverage by `0.24%`.
> The diff coverage is `n/a`.

[![Impacted file tree graph](https://codecov.io/gh/pandas-dev/pandas/pull/19735/graphs/tree.svg?token=eZ4WkYLtcO&width=650&height=150&src=pr)](https://codecov.io/gh/pandas-dev/pandas/pull/19735?src=pr&el=tree)

```diff
@@            Coverage Diff             @@
##           master   #19735      +/-   ##
==========================================
- Coverage   91.82%   91.58%   -0.25%     
==========================================
  Files         152      150       -2     
  Lines       49248    48908     -340     
==========================================
- Hits        45222    44790     -432     
- Misses       4026     4118      +92
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `91.56% <ø> (+1.35%)` | :arrow_up: |
| #single | `32.81% <ø> (-9.09%)` | :arrow_down: |

| [Impacted Files](https://codecov.io/gh/pandas-dev/pandas/pull/19735?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [pandas/tseries/plotting.py](https://codecov.io/gh/pandas-dev/pandas/pull/19735/diff?src=pr&el=tree#diff-cGFuZGFzL3RzZXJpZXMvcGxvdHRpbmcucHk=) | `0% <0%> (-100%)` | :arrow_down: |
| [pandas/core/dtypes/base.py](https://codecov.io/gh/pandas-dev/pandas/pull/19735/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvZHR5cGVzL2Jhc2UucHk=) | `47.61% <0%> (-44.28%)` | :arrow_down: |
| [pandas/plotting/\_compat.py](https://codecov.io/gh/pandas-dev/pandas/pull/19735/diff?src=pr&el=tree#diff-cGFuZGFzL3Bsb3R0aW5nL19jb21wYXQucHk=) | `62% <0%> (-28.91%)` | :arrow_down: |
| [pandas/core/arrays/base.py](https://codecov.io/gh/pandas-dev/pandas/pull/19735/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvYXJyYXlzL2Jhc2UucHk=) | `60% <0%> (-24.15%)` | :arrow_down: |
| [pandas/io/s3.py](https://codecov.io/gh/pandas-dev/pandas/pull/19735/diff?src=pr&el=tree#diff-cGFuZGFzL2lvL3MzLnB5) | `72.72% <0%> (-13.64%)` | :arrow_down: |
| [pandas/core/missing.py](https://codecov.io/gh/pandas-dev/pandas/pull/19735/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvbWlzc2luZy5weQ==) | `85.9% <0%> (-5.75%)` | :arrow_down: |
| [pandas/plotting/\_timeseries.py](https://codecov.io/gh/pandas-dev/pandas/pull/19735/diff?src=pr&el=tree#diff-cGFuZGFzL3Bsb3R0aW5nL190aW1lc2VyaWVzLnB5) | `60.82% <0%> (-4.49%)` | :arrow_down: |
| [pandas/io/formats/console.py](https://codecov.io/gh/pandas-dev/pandas/pull/19735/diff?src=pr&el=tree#diff-cGFuZGFzL2lvL2Zvcm1hdHMvY29uc29sZS5weQ==) | `66.66% <0%> (-3.04%)` | :arrow_down: |
| [pandas/io/html.py](https://codecov.io/gh/pandas-dev/pandas/pull/19735/diff?src=pr&el=tree#diff-cGFuZGFzL2lvL2h0bWwucHk=) | `85.98% <0%> (-2.81%)` | :arrow_down: |
| [pandas/io/formats/format.py](https://codecov.io/gh/pandas-dev/pandas/pull/19735/diff?src=pr&el=tree#diff-cGFuZGFzL2lvL2Zvcm1hdHMvZm9ybWF0LnB5) | `96.25% <0%> (-2%)` | :arrow_down: |
| ... and [58 more](https://codecov.io/gh/pandas-dev/pandas/pull/19735/diff?src=pr&el=tree-more) | |

------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/19735?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/19735?src=pr&el=footer). Last update [cdfce2b...5052897](https://codecov.io/gh/pandas-dev/pandas/pull/19735?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).
 @mikebarkas looks great!

oddly there is 1 less tests here (174 and 1 xfail) vs 175 and 1 xfail on master.

happy to have parameterization of any tests as well. My test build on my fork is failing because  `ImportError: No module named tables`
Looking into it.

I will look for the missing test. This is my missing test
```
def test_longpanel(self):
    pass
```

I will add it back into `test_panel` oh no need to add that back then Hi Mike, are you still working on this? Would be glad to help out or pick it up if you're too busy.  @alsobay I broke the build with latest changes, in a different part of the test suite. I have not had time to determine where and to fix it.

I am currently moving and have little free time. I would appreciate the help to get this PR finished. closing as stale, happy to take an updated PR of this