fix and test index division by zero
State: closed

Related: #19336, this implements the most important parts of the parametrization requested there.

- [ ] closes #xxxx
- [x] tests added / passed
- [ ] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`
- [ ] whatsnew entry


Labels:
name: Dtype Conversions
description: Unexpected or buggy dtype conversions
name: Numeric Operations
description: Arithmetic, Comparison, and Logical operations

Comments:
this needs a sub-section in whatsnew to show what has changed (e.g. Int and Range Index with / 0 and such)
# [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/19347?src=pr&el=h1) Report
> Merging [#19347](https://codecov.io/gh/pandas-dev/pandas/pull/19347?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/69cd5fbfd8b57033b0eb280ebc6dd502652f269c?src=pr&el=desc) will **decrease** coverage by `0.02%`.
> The diff coverage is `100%`.

[![Impacted file tree graph](https://codecov.io/gh/pandas-dev/pandas/pull/19347/graphs/tree.svg?token=eZ4WkYLtcO&src=pr&height=150&width=650)](https://codecov.io/gh/pandas-dev/pandas/pull/19347?src=pr&el=tree)

```diff
@@            Coverage Diff             @@
##           master   #19347      +/-   ##
==========================================
- Coverage   91.69%   91.67%   -0.03%     
==========================================
  Files         148      148              
  Lines       48561    48586      +25     
==========================================
+ Hits        44530    44543      +13     
- Misses       4031     4043      +12
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `90.04% <100%> (-0.02%)` | :arrow_down: |
| #single | `41.71% <22.5%> (-0.01%)` | :arrow_down: |

| [Impacted Files](https://codecov.io/gh/pandas-dev/pandas/pull/19347?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [pandas/core/indexes/range.py](https://codecov.io/gh/pandas-dev/pandas/pull/19347/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvaW5kZXhlcy9yYW5nZS5weQ==) | `95.65% <100%> (-0.06%)` | :arrow_down: |
| [pandas/core/indexes/base.py](https://codecov.io/gh/pandas-dev/pandas/pull/19347/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvaW5kZXhlcy9iYXNlLnB5) | `96.45% <100%> (ø)` | :arrow_up: |
| [pandas/core/missing.py](https://codecov.io/gh/pandas-dev/pandas/pull/19347/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvbWlzc2luZy5weQ==) | `85.9% <100%> (+1.11%)` | :arrow_up: |
| [pandas/plotting/\_converter.py](https://codecov.io/gh/pandas-dev/pandas/pull/19347/diff?src=pr&el=tree#diff-cGFuZGFzL3Bsb3R0aW5nL19jb252ZXJ0ZXIucHk=) | `65.22% <0%> (-1.74%)` | :arrow_down: |

------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/19347?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/19347?src=pr&el=footer). Last update [69cd5fb...be1e2e1](https://codecov.io/gh/pandas-dev/pandas/pull/19347?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).

> the point of conftest is to share.

... isn't that also the point of pandas.util.testing?  
> use getattr

Huh?
fastparquet errors on appveyor
Made `zeros` a fixture in test_numeric as requested, but that broke tests in test_range b/c of pytest magic.  Just pushed a commit that reverted to having `zeros` be a list in test_numeric namespace.
@jreback I think the fixtures are all as requested.  LMK.
thanks. a couple of comments for the future.