ENH: sort=bool keyword argument for index.difference
- [ ] closes #17839
- [ ] tests added / passed
- [ ] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`
- [ ] whatsnew entry

# [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/17878?src=pr&el=h1) Report
> Merging [#17878](https://codecov.io/gh/pandas-dev/pandas/pull/17878?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/aed9b921394efb13ed1b7870508e8638db951101?src=pr&el=desc) will **increase** coverage by `<.01%`.
> The diff coverage is `84.61%`.

[![Impacted file tree graph](https://codecov.io/gh/pandas-dev/pandas/pull/17878/graphs/tree.svg?src=pr&token=eZ4WkYLtcO&height=150&width=650)](https://codecov.io/gh/pandas-dev/pandas/pull/17878?src=pr&el=tree)

```diff
@@            Coverage Diff             @@
##           master   #17878      +/-   ##
==========================================
+ Coverage   91.23%   91.24%   +<.01%     
==========================================
  Files         163      163              
  Lines       50102    50106       +4     
==========================================
+ Hits        45712    45719       +7     
+ Misses       4390     4387       -3
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `89.05% <84.61%> (+0.02%)` | :arrow_up: |
| #single | `40.31% <46.15%> (-0.06%)` | :arrow_down: |

| [Impacted Files](https://codecov.io/gh/pandas-dev/pandas/pull/17878?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [pandas/core/indexes/base.py](https://codecov.io/gh/pandas-dev/pandas/pull/17878?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvaW5kZXhlcy9iYXNlLnB5) | `96.42% <84.61%> (ø)` | :arrow_up: |
| [pandas/io/gbq.py](https://codecov.io/gh/pandas-dev/pandas/pull/17878?src=pr&el=tree#diff-cGFuZGFzL2lvL2dicS5weQ==) | `25% <0%> (-58.34%)` | :arrow_down: |
| [pandas/core/frame.py](https://codecov.io/gh/pandas-dev/pandas/pull/17878?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvZnJhbWUucHk=) | `97.75% <0%> (-0.1%)` | :arrow_down: |
| [pandas/plotting/\_converter.py](https://codecov.io/gh/pandas-dev/pandas/pull/17878?src=pr&el=tree#diff-cGFuZGFzL3Bsb3R0aW5nL19jb252ZXJ0ZXIucHk=) | `65.2% <0%> (+1.81%)` | :arrow_up: |

------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/17878?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/17878?src=pr&el=footer). Last update [aed9b92...f11a40e](https://codecov.io/gh/pandas-dev/pandas/pull/17878?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/17878?src=pr&el=h1) Report
> Merging [#17878](https://codecov.io/gh/pandas-dev/pandas/pull/17878?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/aed9b921394efb13ed1b7870508e8638db951101?src=pr&el=desc) will **increase** coverage by `0.01%`.
> The diff coverage is `84.61%`.

[![Impacted file tree graph](https://codecov.io/gh/pandas-dev/pandas/pull/17878/graphs/tree.svg?height=150&token=eZ4WkYLtcO&width=650&src=pr)](https://codecov.io/gh/pandas-dev/pandas/pull/17878?src=pr&el=tree)

```diff
@@            Coverage Diff             @@
##           master   #17878      +/-   ##
==========================================
+ Coverage   91.23%   91.24%   +0.01%     
==========================================
  Files         163      163              
  Lines       50102    50111       +9     
==========================================
+ Hits        45712    45726      +14     
+ Misses       4390     4385       -5
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `89.06% <84.61%> (+0.02%)` | :arrow_up: |
| #single | `40.31% <46.15%> (-0.06%)` | :arrow_down: |

| [Impacted Files](https://codecov.io/gh/pandas-dev/pandas/pull/17878?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [pandas/core/indexes/base.py](https://codecov.io/gh/pandas-dev/pandas/pull/17878?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvaW5kZXhlcy9iYXNlLnB5) | `96.42% <84.61%> (ø)` | :arrow_up: |
| [pandas/io/gbq.py](https://codecov.io/gh/pandas-dev/pandas/pull/17878?src=pr&el=tree#diff-cGFuZGFzL2lvL2dicS5weQ==) | `25% <0%> (-58.34%)` | :arrow_down: |
| [pandas/core/common.py](https://codecov.io/gh/pandas-dev/pandas/pull/17878?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvY29tbW9uLnB5) | `91.18% <0%> (-1.63%)` | :arrow_down: |
| [pandas/core/frame.py](https://codecov.io/gh/pandas-dev/pandas/pull/17878?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvZnJhbWUucHk=) | `97.75% <0%> (-0.1%)` | :arrow_down: |
| [pandas/core/reshape/pivot.py](https://codecov.io/gh/pandas-dev/pandas/pull/17878?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvcmVzaGFwZS9waXZvdC5weQ==) | `96.35% <0%> (-0.03%)` | :arrow_down: |
| [pandas/core/series.py](https://codecov.io/gh/pandas-dev/pandas/pull/17878?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvc2VyaWVzLnB5) | `94.99% <0%> (ø)` | :arrow_up: |
| [pandas/core/dtypes/dtypes.py](https://codecov.io/gh/pandas-dev/pandas/pull/17878?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvZHR5cGVzL2R0eXBlcy5weQ==) | `95.14% <0%> (ø)` | :arrow_up: |
| [pandas/core/reshape/concat.py](https://codecov.io/gh/pandas-dev/pandas/pull/17878?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvcmVzaGFwZS9jb25jYXQucHk=) | `97.58% <0%> (ø)` | :arrow_up: |
| [pandas/core/groupby.py](https://codecov.io/gh/pandas-dev/pandas/pull/17878?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvZ3JvdXBieS5weQ==) | `92.03% <0%> (+0.05%)` | :arrow_up: |
| [pandas/core/generic.py](https://codecov.io/gh/pandas-dev/pandas/pull/17878?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvZ2VuZXJpYy5weQ==) | `92.53% <0%> (+0.33%)` | :arrow_up: |
| ... and [1 more](https://codecov.io/gh/pandas-dev/pandas/pull/17878?src=pr&el=tree-more) | |

------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/17878?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/17878?src=pr&el=footer). Last update [aed9b92...5039133](https://codecov.io/gh/pandas-dev/pandas/pull/17878?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).
 Hello @Giftlin! Thanks for updating the PR.





Cheers ! There are no PEP8 issues in this Pull Request. :beers: 

##### Comment last updated on October 18, 2017 at 10:23 Hours UTC can you rebase and update according to comments @jreback Can I take over this issue? @Licht-T : Feel free to write your own patch and submit as a separate PR.