Added a tutorial for pandas dataframes
 - [ ] closes #xxxx
 - [ ] tests added / passed
 - [ ] passes ``git diff upstream/master | flake8 --diff``
 - [ ] whatsnew entry

# [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/15295?src=pr&el=h1) Report
> Merging [#15295](https://codecov.io/gh/pandas-dev/pandas/pull/15295?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/df9fc4f17d342cc75b596918b1da1ecaaf0ae54f?src=pr&el=desc) will **increase** coverage by `<.01%`.


```diff
@@            Coverage Diff             @@
##           master   #15295      +/-   ##
==========================================
+ Coverage   86.32%   86.33%   +<.01%     
==========================================
  Files         139      139              
  Lines       51149    51149              
==========================================
+ Hits        44156    44157       +1     
+ Misses       6993     6992       -1
```


| [Impacted Files](https://codecov.io/gh/pandas-dev/pandas/pull/15295?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [pandas/core/common.py](https://codecov.io/gh/pandas-dev/pandas/compare/df9fc4f17d342cc75b596918b1da1ecaaf0ae54f...8305bc4fd3f543d02784ad858ff6e3a70b4f764e?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvY29tbW9uLnB5) | `91.36% <ø> (+0.33%)` | :white_check_mark: |

------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/15295?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/15295?src=pr&el=footer). Last update [df9fc4f...8305bc4](https://codecov.io/gh/pandas-dev/pandas/compare/df9fc4f17d342cc75b596918b1da1ecaaf0ae54f...8305bc4fd3f543d02784ad858ff6e3a70b4f764e?el=footer&src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments). thanks!