BUG/ENH - base argument no longer ignored in period resample
- [ ] closes #23882
- [ ] tests added / passed
- [ ] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`
- [ ] whatsnew entry

Hello @ArtinSarraf! Thanks for updating the PR.

 - There are no PEP8 issues in the file [`pandas/core/resample.py`](https://github.com/ArtinSarraf/pandas/blob/c14dbcea0071be8334511f22820c432e4be96280/pandas/core/resample.py) !

 - There are no PEP8 issues in the file [`pandas/tests/resample/test_period_index.py`](https://github.com/ArtinSarraf/pandas/blob/c14dbcea0071be8334511f22820c432e4be96280/pandas/tests/resample/test_period_index.py) !



##### Comment last updated on December 08, 2018 at 05:00 Hours UTC # [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/23941?src=pr&el=h1) Report
> Merging [#23941](https://codecov.io/gh/pandas-dev/pandas/pull/23941?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/c0371288ff125cad66bc8689ab425dd4cc11c64a?src=pr&el=desc) will **decrease** coverage by `<.01%`.
> The diff coverage is `91.3%`.

[![Impacted file tree graph](https://codecov.io/gh/pandas-dev/pandas/pull/23941/graphs/tree.svg?width=650&token=eZ4WkYLtcO&height=150&src=pr)](https://codecov.io/gh/pandas-dev/pandas/pull/23941?src=pr&el=tree)

```diff
@@            Coverage Diff             @@
##           master   #23941      +/-   ##
==========================================
- Coverage   92.22%   92.22%   -0.01%     
==========================================
  Files         162      162              
  Lines       51785    51805      +20     
==========================================
+ Hits        47758    47776      +18     
- Misses       4027     4029       +2
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `90.62% <91.3%> (-0.01%)` | :arrow_down: |
| #single | `42.99% <8.69%> (-0.02%)` | :arrow_down: |

| [Impacted Files](https://codecov.io/gh/pandas-dev/pandas/pull/23941?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [pandas/core/resample.py](https://codecov.io/gh/pandas-dev/pandas/pull/23941/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvcmVzYW1wbGUucHk=) | `96.58% <91.3%> (-0.24%)` | :arrow_down: |

------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/23941?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/23941?src=pr&el=footer). Last update [c037128...c234cac](https://codecov.io/gh/pandas-dev/pandas/pull/23941?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).
 @jreback - caught a bug in my original bin offset calculation. Previously it was only valid when the index started at the 0 base of the index's frequency. I've fixed that and added several test cases that previously would have failed. can you merge master @jreback - somehow my resample.py file wasn’t updating in my merges. It’s updated now and tests have run clean. I would make a new PR for #24127, specially since there is a test that needed changing which warrants discussion. It's better to limit the scope of this PR. @mroeschke - reverted the changes here and added a new PR.
https://github.com/pandas-dev/pandas/pull/24159 @jreback / @mroeschke - anything else to consider? thanks @ArtinSarraf 