Slicing an index with DateTime throws AttributeError: 'int' object has no attribute 'stop'
Fixes GH26944 AttributeError on partial multiindex timestamp slice

- [x] closes #26944
- [x] tests added / passed
- [x] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`
- [x] whatsnew entry

# [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/27127?src=pr&el=h1) Report
> Merging [#27127](https://codecov.io/gh/pandas-dev/pandas/pull/27127?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/b640530a788206fb445a7295fafdf9ed53b78567?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/27127/graphs/tree.svg?width=650&token=eZ4WkYLtcO&height=150&src=pr)](https://codecov.io/gh/pandas-dev/pandas/pull/27127?src=pr&el=tree)

```diff
@@            Coverage Diff             @@
##           master   #27127      +/-   ##
==========================================
- Coverage   91.87%   91.86%   -0.01%     
==========================================
  Files         180      180              
  Lines       50864    50866       +2     
==========================================
- Hits        46731    46729       -2     
- Misses       4133     4137       +4
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `90.51% <100%> (ø)` | :arrow_up: |
| #single | `41.87% <0%> (-0.09%)` | :arrow_down: |

| [Impacted Files](https://codecov.io/gh/pandas-dev/pandas/pull/27127?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [pandas/core/indexes/multi.py](https://codecov.io/gh/pandas-dev/pandas/pull/27127/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvaW5kZXhlcy9tdWx0aS5weQ==) | `94.86% <100%> (ø)` | :arrow_up: |
| [pandas/io/gbq.py](https://codecov.io/gh/pandas-dev/pandas/pull/27127/diff?src=pr&el=tree#diff-cGFuZGFzL2lvL2dicS5weQ==) | `88.88% <0%> (-11.12%)` | :arrow_down: |
| [pandas/core/frame.py](https://codecov.io/gh/pandas-dev/pandas/pull/27127/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvZnJhbWUucHk=) | `96.88% <0%> (-0.12%)` | :arrow_down: |

------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/27127?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/27127?src=pr&el=footer). Last update [b640530...ecc8d45](https://codecov.io/gh/pandas-dev/pandas/pull/27127?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/27127?src=pr&el=h1) Report
> Merging [#27127](https://codecov.io/gh/pandas-dev/pandas/pull/27127?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/b640530a788206fb445a7295fafdf9ed53b78567?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/27127/graphs/tree.svg?width=650&token=eZ4WkYLtcO&height=150&src=pr)](https://codecov.io/gh/pandas-dev/pandas/pull/27127?src=pr&el=tree)

```diff
@@            Coverage Diff             @@
##           master   #27127      +/-   ##
==========================================
- Coverage   91.87%   91.86%   -0.01%     
==========================================
  Files         180      180              
  Lines       50864    50819      -45     
==========================================
- Hits        46731    46687      -44     
+ Misses       4133     4132       -1
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `90.55% <100%> (+0.04%)` | :arrow_up: |
| #single | `41.92% <0%> (-0.04%)` | :arrow_down: |

| [Impacted Files](https://codecov.io/gh/pandas-dev/pandas/pull/27127?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [pandas/core/indexes/multi.py](https://codecov.io/gh/pandas-dev/pandas/pull/27127/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvaW5kZXhlcy9tdWx0aS5weQ==) | `94.86% <100%> (ø)` | :arrow_up: |
| [pandas/io/gbq.py](https://codecov.io/gh/pandas-dev/pandas/pull/27127/diff?src=pr&el=tree#diff-cGFuZGFzL2lvL2dicS5weQ==) | `88.88% <0%> (-11.12%)` | :arrow_down: |
| [pandas/core/panel.py](https://codecov.io/gh/pandas-dev/pandas/pull/27127/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvcGFuZWwucHk=) | `15.86% <0%> (-0.24%)` | :arrow_down: |
| [pandas/core/frame.py](https://codecov.io/gh/pandas-dev/pandas/pull/27127/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvZnJhbWUucHk=) | `96.87% <0%> (-0.14%)` | :arrow_down: |
| [pandas/core/internals/blocks.py](https://codecov.io/gh/pandas-dev/pandas/pull/27127/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvaW50ZXJuYWxzL2Jsb2Nrcy5weQ==) | `94.97% <0%> (-0.08%)` | :arrow_down: |
| [pandas/core/indexes/datetimes.py](https://codecov.io/gh/pandas-dev/pandas/pull/27127/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvaW5kZXhlcy9kYXRldGltZXMucHk=) | `94.16% <0%> (-0.07%)` | :arrow_down: |
| [pandas/core/arrays/categorical.py](https://codecov.io/gh/pandas-dev/pandas/pull/27127/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvYXJyYXlzL2NhdGVnb3JpY2FsLnB5) | `95.91% <0%> (-0.03%)` | :arrow_down: |
| [pandas/io/formats/csvs.py](https://codecov.io/gh/pandas-dev/pandas/pull/27127/diff?src=pr&el=tree#diff-cGFuZGFzL2lvL2Zvcm1hdHMvY3N2cy5weQ==) | `98.18% <0%> (-0.02%)` | :arrow_down: |
| [pandas/core/series.py](https://codecov.io/gh/pandas-dev/pandas/pull/27127/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvc2VyaWVzLnB5) | `92.35% <0%> (-0.01%)` | :arrow_down: |
| [pandas/io/html.py](https://codecov.io/gh/pandas-dev/pandas/pull/27127/diff?src=pr&el=tree#diff-cGFuZGFzL2lvL2h0bWwucHk=) | `94.24% <0%> (ø)` | :arrow_up: |
| ... and [5 more](https://codecov.io/gh/pandas-dev/pandas/pull/27127/diff?src=pr&el=tree-more) | |

------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/27127?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/27127?src=pr&el=footer). Last update [b640530...f8dfd84](https://codecov.io/gh/pandas-dev/pandas/pull/27127?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).
 Hello @soilstack! Thanks for updating this PR. We checked the lines you've touched for [PEP 8](https://www.python.org/dev/peps/pep-0008) issues, and found:





There are currently no PEP 8 issues detected in this Pull Request. Cheers! :beers: 

##### Comment last updated at 2019-07-01 15:42:06 UTC > Needs a test.

done oops accidentally closed Thanks!