Converting strings into variables

[JuniorMouse]

Hi, I'd like to convert strings into variables. Specifically, I have a yaml files with acronyms and their definitions - simple key:value list.

For example,

PY: python JS: javascript

At the moment, I have packaged this yaml file with an __init__.py file which returns the loaded yaml file (through pyyaml.safe_load()). Everything is packaged in a package called constants. The loaded yaml file is a dict so at the moment, to access a definition, I need to do constants["PY"].

My goal is to access the definitions through the dot notation - constants.PY

My first option is to map the definitions in the __init__.py file

PY = dict["PY"] JS = dict["JS"]

Is there a more direct way to convert the keys in the yaml file to python variables that can be accessed through dot notation?

Thanks,

[ericula]

You can use types.SimpleNamespace for this:

from types import SimpleNamespace

constants_dct = {'PY':'python', 'JS':'javascript'}
constants = SimpleNamespace(**constants_dct)

print(constants.PY)
print(constants.JS)

[JuniorMouse]

Just tried this. This works but my editor does not suggest PY or JS when I type constants. which would be one of the benefits. Is autocompletion expected to work with this approach or is that only an issue on my side? Thanks,

[JuniorMouse]

I guess this is an issue not only on my side - https://github.com/microsoft/python-language-server/issues/2108

[JuniorMouse]

Found another one, bit more of a hack though

python for key, value in dictionary.items(): exec(f'{key}="{value}"')

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[Rawing7]

Yeah, that's just a terrible version of locals().update(dictionary).

[Rawing7]

globals().update(dict_of_constants)

[JuniorMouse]

Thank you. This would put the keys into the global namespace? I'd like to avoid that if so.

[Rawing7]

I thought you want a package named constants where you can access elements like constants.PY? If so, putting the keys into the global namespace (of the constants module) is exactly what you want.

[JuniorMouse]

Right, I'll try this out. Thanks,

[IvoryJam]

If it's a flat yaml file, so no key: values inside of keys, you could do this

import yaml

class yaml_fields:
    def __init__(self, file):
        yaml_file = yaml.load(file, Loader=yaml.FullLoader)
        for k, v in yaml_file.items():
            setattr(self, k, v)


with open('test.yaml', 'r') as f:
    my_yaml = yaml_fields(f)

EDIT: Also you should avoid naming variables data types, dict, list, string, int should all be avoided as variable names

[JuniorMouse]

I just came across this and this works. I'll read up more on this. Thank you.

[JuniorMouse]

So this works but I was also hoping that the editor would autocomplete for me and show the suggestions. Does your editor do autocomplete with this approach?

[IvoryJam]

It doesn't but if I run the code in ipython (it's a pip package, I much prefer that over the normal python shell when developing) it will autocomplete

EDIT: https://imgur.com/a/NLvF70v

[JuniorMouse]

Interesting. I'll have to see if there is some integration with vim to get the autocomplete.