DOC: Updating str_pad docstring
Added Examples to docstring.
Added documentation to each part of docstring
# [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/22570?src=pr&el=h1) Report
> Merging [#22570](https://codecov.io/gh/pandas-dev/pandas/pull/22570?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/98fb53ca2d64658749e9f182b391002ef3500c1b?src=pr&el=desc) will **increase** coverage by `0.14%`.
> The diff coverage is `100%`.

[![Impacted file tree graph](https://codecov.io/gh/pandas-dev/pandas/pull/22570/graphs/tree.svg?width=650&token=eZ4WkYLtcO&height=150&src=pr)](https://codecov.io/gh/pandas-dev/pandas/pull/22570?src=pr&el=tree)

```diff
@@            Coverage Diff             @@
##           master   #22570      +/-   ##
==========================================
+ Coverage   92.04%   92.18%   +0.14%     
==========================================
  Files         169      169              
  Lines       50787    50810      +23     
==========================================
+ Hits        46745    46839      +94     
+ Misses       4042     3971      -71
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `90.6% <100%> (+0.14%)` | :arrow_up: |
| #single | `42.37% <0%> (+0.08%)` | :arrow_up: |

| [Impacted Files](https://codecov.io/gh/pandas-dev/pandas/pull/22570?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [pandas/core/strings.py](https://codecov.io/gh/pandas-dev/pandas/pull/22570/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvc3RyaW5ncy5weQ==) | `98.63% <100%> (-0.01%)` | :arrow_down: |
| [pandas/io/clipboard/clipboards.py](https://codecov.io/gh/pandas-dev/pandas/pull/22570/diff?src=pr&el=tree#diff-cGFuZGFzL2lvL2NsaXBib2FyZC9jbGlwYm9hcmRzLnB5) | `28.23% <0%> (-2.36%)` | :arrow_down: |
| [pandas/compat/\_\_init\_\_.py](https://codecov.io/gh/pandas-dev/pandas/pull/22570/diff?src=pr&el=tree#diff-cGFuZGFzL2NvbXBhdC9fX2luaXRfXy5weQ==) | `58.43% <0%> (-0.18%)` | :arrow_down: |
| [pandas/core/indexes/base.py](https://codecov.io/gh/pandas-dev/pandas/pull/22570/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvaW5kZXhlcy9iYXNlLnB5) | `96.39% <0%> (-0.06%)` | :arrow_down: |
| [pandas/core/dtypes/inference.py](https://codecov.io/gh/pandas-dev/pandas/pull/22570/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvZHR5cGVzL2luZmVyZW5jZS5weQ==) | `98.38% <0%> (-0.03%)` | :arrow_down: |
| [pandas/core/indexes/period.py](https://codecov.io/gh/pandas-dev/pandas/pull/22570/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvaW5kZXhlcy9wZXJpb2QucHk=) | `93.48% <0%> (-0.02%)` | :arrow_down: |
| [pandas/core/indexes/category.py](https://codecov.io/gh/pandas-dev/pandas/pull/22570/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvaW5kZXhlcy9jYXRlZ29yeS5weQ==) | `97.26% <0%> (-0.02%)` | :arrow_down: |
| [pandas/core/frame.py](https://codecov.io/gh/pandas-dev/pandas/pull/22570/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvZnJhbWUucHk=) | `97.2% <0%> (-0.01%)` | :arrow_down: |
| [pandas/core/indexes/accessors.py](https://codecov.io/gh/pandas-dev/pandas/pull/22570/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvaW5kZXhlcy9hY2Nlc3NvcnMucHk=) | `90.09% <0%> (ø)` | :arrow_up: |
| ... and [48 more](https://codecov.io/gh/pandas-dev/pandas/pull/22570/diff?src=pr&el=tree-more) | |

------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/22570?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/22570?src=pr&el=footer). Last update [98fb53c...c785311](https://codecov.io/gh/pandas-dev/pandas/pull/22570?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).
 Hello @JesperDramsch! Thanks for updating the PR.



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

##### Comment last updated on September 03, 2018 at 17:10 Hours UTC @datapythonista  @JesperDramsch do you have time to address the previous comments? > @JesperDramsch do you have time to address the previous comments?

I'll get to it this weekend, I think. I think I addressed all comments and validated it. @datapythonista  @JesperDramsch Pushed some last small changes. Thanks a lot for the PR!