How to convert a Dataset into an indexed dataset / association-of-associations given a column header?

Given a dataset as such


If "letter" is the header that is chosen, how do I convert it into an indexed dataset / association-of-associations?

i.e. How do I define f such that f[dataset_,columnHeader_] produces the following?

enter image description here

Please note GroupBy is close but fails as you are unable to use Part to work with the result to extract column data. eg:

data = {<|"letter" -> "a", "foo" -> 1, "bar" -> 2|>, <|"letter" -> "b", "foo" -> 3, "bar" -> 4|>, <|"letter" -> "c", "foo" -> 5, "bar" -> 6|>}; dataDS = Dataset[data]; dataDSg= GroupBy[dataDS, Key["letter"]]; dataDSg[All, "foo"] (* <- produces an error *) 

Where as data in the format of an association-of-association works fine

data2 = <|"a" -> <|"foo" -> 1, "bar" -> 2|>, "b" -> <|"foo" -> 3, "bar" -> 4|>, "c" -> <|"foo" -> 5, "bar" -> 6|>|>; data2DS = data2 // Dataset; data2DS [All, "foo"] (* <- returns a dataset with 1,3,5 *) 

How do I prevent the page from rendering the header seconds before the content?

Dealing with a rough issue here. Currently have no site optimization configured (that I am aware of) but for all pages on the site, the header loads a significant amount of time before the rest of the page content. This is causing a large issue with CLS on Google, as the page shifts when the body of the page is rendered. Is there any way that I can enforce them to load at the same time? This only became an issue recently.

Are there such thing as header files in unity/C#?

I am new to unity, and I love organizing. This is my issue: say I have two different scripts, Sword and Spear. Two of which share common stuff, such as an enum Size {Small, Medium, Large}, they also share the same class DamageAttributes, which contains information regarding their damage as well as methods to calculate them. This is my attempt to abstract my actual problem, what I would like to do is to declare the enum and the classes in a fashion similar to .h in C++, so I have a place where I know they will be, and I can put other stuff that will be shared into it as well. Is there a good way to implement this?

What do the symbols in the header of Hunter-Net Mean?

Hunter-Net is the messageboard/list serv archive that the Imbued use in Hunter: The Reckoning. The header to the site looks like this:

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What do the symbols (hunter code) in the header mean? The symbol on the right means "hope", but I can’t find the symbol on the left in any of the dozen or so Hunter books I own. It also doesn’t appear on the WhiteWolf fan wiki.

So what does it mean?

Do I really need to have header attributes in elements [closed]

I’m trying to make a website I’m working on meet accessibility requirements. I’ve checked it at which complains about all the <td> elements in my tables not having id and header attributes. The message from the checker was:

Check 245: Data table with more than one row/column of headers does not use id and headers attributes to identify cells. Repair: Add id and headers attributes to table cells so they identify the cells that relate to the headers. 

This implies that each <th> element should have an id attribute and each <td> should have a header attribute pointing to the relevant <th> elements. This method is described in

I have already specified a scope for all the header elements in accordance with so I wouldn’t have expected it to be necessary to include header tags in the <td> elements as well, especially since the notes in H63.html suggest that for simple tables that have the headers in the first row or column then it is sufficient to simply use the <th> elements without scope and only suggests that the extra id and header attributes required in H43.html should be used in more complex tables.

Here’s a simplified pruned down example of one of my tables:

<table> <caption>Full council Meetings in 2020</caption> <thead>     <tr>         <th scope="col">Meeting date</th>         <th scope="col">Agenda</th>         <th scope="col">Minutes</th>         <th scope="col">Attachments</th>     </tr> </thead> <tbody>     <tr>         <th scope="row">Jan 9th 2020</th>         <td><a href="">view</a></td>         <td><a href="">view</a></td>         <td>&nbsp;</td>     </tr>     <tr>         <th scope="row">Feb 13th 2020</th>         <td><a href="">view</a></td>         <td><a href="">view</a></td>         <td><a href="">view</a></td>     </tr> </tbody> </table> 

This leads me to wonder if the accessibility checker is being over pedantic?

I could easily add the header tags if needed but I’m reluctant to add extra bloat if it’s not needed.

header > img not selecting working

On my website, I can't select a particular image (in order to style it to width: 180px). Note that it is currently the right size because I was forced to use inline style, but I want it be controlled with CSS.

It is an img inside of a header parent, but:

header > img

doesn't select it. Neither does img#logo (an id I put on it).

Weirdly, this works perfectly both when directly opening the site from my C: drive and while opening it using my ampps local host, also on my…

header > img not selecting working