Feature/config system

[giulioungaretti]

See #341 .

It's not 100% done yet, and I think that maybe we should allow live updating the configs.
But also maybe not :/
@MerlinSmiles @eendebakpt !

• nice error message
• only save user changed settings
• dot notation for configure object (+ docstrings???)
• sharing cofigs (f.ex. size of figures, but not path)
  • f.ex. head of experiment decides that files should have common naming so creates a config file with the defaults and voila all the students/researchers have it
• better names, config.json sucks

[AdriaanRol]

@giulioungaretti This looks pretty interesting, I'd definately be interested in using this.

I read through the readme of the config (didn't look at the acual code) but it was not clear how to use this. Do you think it would make sense to include use of the config in the example ipython notebook and also add an example of how to use it in the config readme?

I'm talking about a piece of code that can be executed or very explicit some file that needs to be present. Configs usually tend to be the things that I break :)

[giulioungaretti]

@AdriaanRol ah, I assumed the doc was enough, but maybe it's not.

[peendebak]

@giulioungaretti Config system looks good. It is a bit more complex that some of the default python systems (e.g. configparser), but then it also has some more functionality.

Maybe we should consider adding some convenience functions such as .get_float which would get a config value and convert it to float (or generate an error if conversion is not possible).

[giulioungaretti]

@peendebak json does not know the difference between float and int, if type is number then they are the same.
Python will get the float though.

[qcodes-bot]

Here is an overview of what got changed by this pull request:

Issues
======
- Added 2


Complexity increasing per file
==============================
- qcodes/tests/test_config.py  2
- qcodes/config/config.py  7


Clones added
============
- qcodes/tests/test_config.py  20

See the complete overview on Codacy

[giulioungaretti]

@AdriaanRol @AdriaanRol https://github.com/qdev-dk/Qcodes/blob/8057ec3b14369ae4366ef570366f1ee12b7dc476/docs/examples/Configuring_QCoDeS.ipynb
does this make it nicer to understand how to use it ?

[AdriaanRol]

@giulioungaretti I like the new config explanation notebook. It indeed explains how to make a new config file and how to use it 👍

I cannot say I am a fan of helper functions but that's a matter of personal preference and I'll acknowledge that I don't have to use those.

Other points where I think it can be improved is a good template settings file (you can abuse the default config file for that). If you want a good example of what I am talking about think the sublime config files.
I did find the default config file which is rather limited (only 2 options are so are set). And the other one could use improved comments.

Hope this helps.

[giulioungaretti]

@AdriaanRol sweet, there's not much to configure as of v0.1.
And surely you may want to not use the helper, but then you also need the validation files.
Which of course are not required, but it will warn you that you are doing it wrong.

[MerlinSmiles]

@giulioungaretti I took a look at the config system too, and I'm quite happy with it.

@AdriaanRol I do like the sublime way of config files too. Especially the comments. However, that is not standard json and if I recall correctly is kindof annoying to implement. (There is commentjson though)

Another thing I like about the sublime config is the file naming *.sublime-config it is very clear, and it does allow for several config files. I would like if we adopt something similar, then we could have different config files like plotting.qcodes-config, file_system.qcodes-config, setup.qcodes-config, merlin.qcodes-config and so on, that would allow for organizing, sharing, and enforcing (i.e. filenames) of configs, while still allowing for user specific changes.

In this PR the home config file is saved as ~/qcodesrc.json I would like if all the user qcodes files jump into a ~/.qcodes/ directory, in the case of several config files they would be organized in one place. Not sure what could be added there in the future, maybe templates for logbooks...

[giulioungaretti]

@MerlinSmiles it's a very cool idea, and I see the use of it! For now I think this is it, and we'll work out how to make it super shiny in the next versions!
@MerlinSmiles also, nothing stops you from hacking your way and have a custom location set in your env_variables, which you could also define in a notebook :P

[MerlinSmiles]

@giulioungaretti I was just thinking that those changes would break the current config in the future, so it might be useful to implement the pattern now, without the fancyness. But thats of course totally up to you.

Of course nothing stops me from hacking, I always edit in master thats so much easier 😍

[giulioungaretti]

@MerlinSmiles actually they won't break :D It's just a matter of implementing the priority and filenames :D

[MerlinSmiles]

@giulioungaretti another reason for a ~/.qcodes/ folder is the schema.json file, not sure why that nonunique file should sit directly in home, without any connection to qcodes...

[giulioungaretti]

@MerlinSmiles but are people familiar enough with hidden files/directories ?
But you are right, schema.json should be called qcodesrc_schema.json!

[MerlinSmiles]

@giulioungaretti I'm not sure about the hidden files/dirs, but it seems to be semi standard among package configs, no? At least I have some of those folders.

Actually trying to find info about that, its like a broken way of using unix apps on windows and %APPDATA%\qcodes\ would be the right place.
http://stackoverflow.com/questions/2243895/location-to-put-user-configuration-files-in-windows/2243910#2243910
Funny enough but %APPDATA% is hidden by default in windows, which has annoyed me for years :)

[MerlinSmiles]

also this suggests %APPDATA%, maybe that is also where logfiles should go at some point?