DEPR: Series ndarray properties (strides, data, base, itemsize, flags)
- [x] closes #20419
- [ ] tests added / passed
- [ ] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`
- [ ] whatsnew entry

Hello @jorisvandenbossche! Thanks for updating the PR.























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

##### Comment last updated on April 24, 2018 at 12:42 Hours UTC # [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/20721?src=pr&el=h1) Report
> Merging [#20721](https://codecov.io/gh/pandas-dev/pandas/pull/20721?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/0ae7e9090cee6e10ebb4124a0b7f3b30811ccc53?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/20721/graphs/tree.svg?token=eZ4WkYLtcO&src=pr&height=150&width=650)](https://codecov.io/gh/pandas-dev/pandas/pull/20721?src=pr&el=tree)

```diff
@@            Coverage Diff             @@
##           master   #20721      +/-   ##
==========================================
- Coverage   91.85%   91.84%   -0.01%     
==========================================
  Files         153      153              
  Lines       49308    49316       +8     
==========================================
+ Hits        45290    45296       +6     
- Misses       4018     4020       +2
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `90.24% <100%> (-0.01%)` | :arrow_down: |
| #single | `41.89% <25%> (-0.01%)` | :arrow_down: |

| [Impacted Files](https://codecov.io/gh/pandas-dev/pandas/pull/20721?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [pandas/core/algorithms.py](https://codecov.io/gh/pandas-dev/pandas/pull/20721/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvYWxnb3JpdGhtcy5weQ==) | `94.37% <100%> (ø)` | :arrow_up: |
| [pandas/core/internals.py](https://codecov.io/gh/pandas-dev/pandas/pull/20721/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvaW50ZXJuYWxzLnB5) | `95.58% <100%> (ø)` | :arrow_up: |
| [pandas/core/base.py](https://codecov.io/gh/pandas-dev/pandas/pull/20721/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvYmFzZS5weQ==) | `96.83% <100%> (+0.03%)` | :arrow_up: |
| [pandas/core/indexes/category.py](https://codecov.io/gh/pandas-dev/pandas/pull/20721/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvaW5kZXhlcy9jYXRlZ29yeS5weQ==) | `97.03% <0%> (-0.27%)` | :arrow_down: |
| [pandas/core/arrays/categorical.py](https://codecov.io/gh/pandas-dev/pandas/pull/20721/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvYXJyYXlzL2NhdGVnb3JpY2FsLnB5) | `95.64% <0%> (-0.14%)` | :arrow_down: |

------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/20721?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/20721?src=pr&el=footer). Last update [0ae7e90...feb7caf](https://codecov.io/gh/pandas-dev/pandas/pull/20721?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).
 can you update Now that #20745 is merged, updated this. @jorisvandenbossche a couple new warnings I think: https://travis-ci.org/pandas-dev/pandas/jobs/369977719#L2762

```
pandas/tests/indexes/datetimes/test_datetimelike.py::TestDatetimeIndex::()::test_copy_name
  /Users/travis/build/pandas-dev/pandas/pandas/core/indexes/base.py:551: FutureWarning: DatetimeIndex.base is deprecated and will be removed in a future version
    orig = orig if orig.base is None else orig.base
pandas/tests/internals/test_internals.py::TestBlockManager::()::test_copy
  /Users/travis/build/pandas-dev/pandas/pandas/tests/internals/test_internals.py:469: FutureWarning: DatetimeIndex.base is deprecated and will be removed in a future version
    assert cp_blk.values.base is blk.values.base
  /Users/travis/build/pandas-dev/pandas/pandas/tests/internals/test_internals.py:477: FutureWarning: DatetimeIndex.base is deprecated and will be removed in a future version
    if cp_blk.values.base is not None and blk.values.base is not None:
  /Users/travis/build/pandas-dev/pandas/pandas/tests/internals/test_internals.py:478: FutureWarning: DatetimeIndex.base is deprecated and will be removed in a future version
    assert cp_blk.values.base is not blk.values.base
```

Can you see if they're easy to fix? lgtm, other than @TomAugspurger comments. lgtm. modulo any warnings fixes. note that I just pushed a CI fix for lint (on other PR) Thanks @jorisvandenbossche  I was doing scipy.fftpack.fft over a series and it showed error as
Attriute error: Series object has no attribute flags.

What should I use instead? And how to overcome it?