DOC: Clean up of DataFrame.ewm
State: closed

- [ ] closes #31647
Though, I don't know what @MarcoGorelli meant in the 5'th issue.

Didn't know how to expand my previous Pull Request: #32212, as I have already deleted the files on my machine.

Here are the screenshots, @WillAyd:

![image](https://user-images.githubusercontent.com/12001304/75212620-caa16e00-5787-11ea-9bd9-532f557d3e33.png)

![image](https://user-images.githubusercontent.com/12001304/75213997-50271d00-578c-11ea-82e0-5f5b986ede6d.png)


In the first image a controversial change might be: log(0.5) -> -ln(2).
The Notes have been expanded with a simple example from the provided link.

Labels:

Comments:
Hello @sursu! Thanks for updating this PR. We checked the lines you've touched for [PEP 8](https://www.python.org/dev/peps/pep-0008) issues, and found:

* In the file [`pandas/core/window/ewm.py`](https://github.com/pandas-dev/pandas/blob/0b25053d058b967bcc6aa4affd1428031c21a93e/pandas/core/window/ewm.py):

> [Line 74:87](https://github.com/pandas-dev/pandas/blob/0b25053d058b967bcc6aa4affd1428031c21a93e/pandas/core/window/ewm.py#L74): [W291](https://duckduckgo.com/?q=pep8%20W291) trailing whitespace
> [Line 80:85](https://github.com/pandas-dev/pandas/blob/0b25053d058b967bcc6aa4affd1428031c21a93e/pandas/core/window/ewm.py#L80): [W291](https://duckduckgo.com/?q=pep8%20W291) trailing whitespace
> [Line 81:27](https://github.com/pandas-dev/pandas/blob/0b25053d058b967bcc6aa4affd1428031c21a93e/pandas/core/window/ewm.py#L81): [W291](https://duckduckgo.com/?q=pep8%20W291) trailing whitespace
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> [Line 85:88](https://github.com/pandas-dev/pandas/blob/0b25053d058b967bcc6aa4affd1428031c21a93e/pandas/core/window/ewm.py#L85): [W291](https://duckduckgo.com/?q=pep8%20W291) trailing whitespace
> [Line 88:1](https://github.com/pandas-dev/pandas/blob/0b25053d058b967bcc6aa4affd1428031c21a93e/pandas/core/window/ewm.py#L88): [E101](https://duckduckgo.com/?q=pep8%20E101) indentation contains mixed spaces and tabs
> [Line 88:1](https://github.com/pandas-dev/pandas/blob/0b25053d058b967bcc6aa4affd1428031c21a93e/pandas/core/window/ewm.py#L88): [W191](https://duckduckgo.com/?q=pep8%20W191) indentation contains tabs
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> [Line 89:71](https://github.com/pandas-dev/pandas/blob/0b25053d058b967bcc6aa4affd1428031c21a93e/pandas/core/window/ewm.py#L89): [W291](https://duckduckgo.com/?q=pep8%20W291) trailing whitespace
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> [Line 92:1](https://github.com/pandas-dev/pandas/blob/0b25053d058b967bcc6aa4affd1428031c21a93e/pandas/core/window/ewm.py#L92): [E101](https://duckduckgo.com/?q=pep8%20E101) indentation contains mixed spaces and tabs
> [Line 92:77](https://github.com/pandas-dev/pandas/blob/0b25053d058b967bcc6aa4affd1428031c21a93e/pandas/core/window/ewm.py#L92): [W291](https://duckduckgo.com/?q=pep8%20W291) trailing whitespace
> [Line 96:5](https://github.com/pandas-dev/pandas/blob/0b25053d058b967bcc6aa4affd1428031c21a93e/pandas/core/window/ewm.py#L96): [E101](https://duckduckgo.com/?q=pep8%20E101) indentation contains mixed spaces and tabs
> [Line 96:5](https://github.com/pandas-dev/pandas/blob/0b25053d058b967bcc6aa4affd1428031c21a93e/pandas/core/window/ewm.py#L96): [W191](https://duckduckgo.com/?q=pep8%20W191) indentation contains tabs
> [Line 97:5](https://github.com/pandas-dev/pandas/blob/0b25053d058b967bcc6aa4affd1428031c21a93e/pandas/core/window/ewm.py#L97): [E101](https://duckduckgo.com/?q=pep8%20E101) indentation contains mixed spaces and tabs
> [Line 97:5](https://github.com/pandas-dev/pandas/blob/0b25053d058b967bcc6aa4affd1428031c21a93e/pandas/core/window/ewm.py#L97): [W191](https://duckduckgo.com/?q=pep8%20W191) indentation contains tabs
> [Line 97:20](https://github.com/pandas-dev/pandas/blob/0b25053d058b967bcc6aa4affd1428031c21a93e/pandas/core/window/ewm.py#L97): [W291](https://duckduckgo.com/?q=pep8%20W291) trailing whitespace
> [Line 98:5](https://github.com/pandas-dev/pandas/blob/0b25053d058b967bcc6aa4affd1428031c21a93e/pandas/core/window/ewm.py#L98): [E101](https://duckduckgo.com/?q=pep8%20E101) indentation contains mixed spaces and tabs
> [Line 98:5](https://github.com/pandas-dev/pandas/blob/0b25053d058b967bcc6aa4affd1428031c21a93e/pandas/core/window/ewm.py#L98): [W191](https://duckduckgo.com/?q=pep8%20W191) indentation contains tabs
> [Line 99:5](https://github.com/pandas-dev/pandas/blob/0b25053d058b967bcc6aa4affd1428031c21a93e/pandas/core/window/ewm.py#L99): [E101](https://duckduckgo.com/?q=pep8%20E101) indentation contains mixed spaces and tabs
> [Line 99:5](https://github.com/pandas-dev/pandas/blob/0b25053d058b967bcc6aa4affd1428031c21a93e/pandas/core/window/ewm.py#L99): [W191](https://duckduckgo.com/?q=pep8%20W191) indentation contains tabs
> [Line 100:1](https://github.com/pandas-dev/pandas/blob/0b25053d058b967bcc6aa4affd1428031c21a93e/pandas/core/window/ewm.py#L100): [W293](https://duckduckgo.com/?q=pep8%20W293) blank line contains whitespace
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##### Comment last updated at 2020-02-25 04:03:39 UTC
> Didn't know how to expand my previous Pull Request: #32212, as I have already deleted the files on my machine.

Can you continue back in that PR? Comments are already filed therein so shouldn't open a new PR as it makes things more difficult to track

If you don't have on your machine just pull from your remote branch to restore