Making command-line args available to deeply-nested functions

[Loris Bennett]

George Fischhof <george at fischhof.hu> writes:

> George Fischhof <george at fischhof.hu> ezt írta (időpont: 2021. aug. 29., V,
> 21:27):
>
>>
>>
>> Loris Bennett <loris.bennett at fu-berlin.de> ezt írta (időpont: 2021. aug.
>> 26., Cs, 16:02):
>>
>>> George Fischhof <george at fischhof.hu> writes:
>>>
>>> [snip (79 lines)]
>>>
>>> >> > Hi,
>>> >> >
>>> >> > Also you can give a try to click and / or  typer packages.
>>> >> > Putting args into environment variables can be a solution too
>>> >> > All of these depends on several things: personal preferences,
>>> colleagues
>>> >> /
>>> >> > firm standards, the program, readability, variable accessibility (IDE
>>> >> > support, auto completition) (env vars not supported by IDEs as they
>>> are
>>> >> not
>>> >> > part of code)
>>> >>
>>> >> Thanks for the pointers, although I have only just got my head around
>>> >> argparse/configargparse, so click is something I might have a look at
>>> >> for future project.
>>> >>
>>> >> However, the question of how to parse the arguments is somewhat
>>> separate
>>> >> from that of how to pass (or not pass) the arguments around within a
>>> >> program.
>>>
>>> [snip (16 lines)]
>>> >
>>> > Hi,
>>> > I thought not just parsing, but the usage method: you add a decorator to
>>> > the function where you want to use the parameters. This way you do not
>>> have
>>> > to pass the value through the calling hierarchy.
>>> >
>>> > Note: typer is a newer package, it contains click and leverages command
>>> > line parsing even more.
>>>
>>> Do you have an example of how this is done?  From a cursory reading of
>>> the documentation, it didn't seem obvious to me how to do this, but then
>>> I don't have much understanding of how decorators work.
>>>
>>> Cheers,
>>>
>>> Loris
>>>
>>>
>>> --
>>> This signature is currently under construction.
>>> --
>>> https://mail.python.org/mailman/listinfo/python-list
>>
>>
>> Hi,
>>
>> will create a sample code on Monday - Tuesday
>>
>> BR,
>> George
>>
>
>
> Hi,
>
> here is the program ;-) (see below)
> typer does not uses decorators, to solve this problem they advice to use
> click's decorators, mixing typer and click.
> Practically I prefer not to mix them, also the parts for easiest way to do
> this just available in latest click, which is not supported in typer.
>
> So I created all the stuff in click, 8.x should be used
>
> BR,
> George
>
>
> import click
>
>
> # read command line parameters
> @click.command()
> @click.option('--level_1', help='Level 1')
> @click.option('--level_2', help='Level 2')
> def main(level_1, level_2):
>     # put command line parameters into global context
>     ctx = click.get_current_context()
>     ctx.meta['level_1'] = level_1
>     ctx.meta['level_2'] = level_2
>
>     level_1_function()
>
>
> # pass / inject level_1 parameter to this function
> @click.decorators.pass_meta_key('level_1')
> def level_1_function(level_1):
>     print(f'level 1 variable: {level_1}')
>     level_2_function()
>
>
> # pass / inject level_2 parameter to this function
> @click.decorators.pass_meta_key('level_2')
> def level_2_function(level_2):
>     print(f'level 2 variable: {level_2}')
>
>
> if __name__ == "__main__":
>     main()

Thanks for the example - that's very interesting.  However, after a bit
of reflection I think I am going to stick to explicit argument passing,
so that I can have more generic modules that can be used by other
programs.  I'll then just encapsulate the argument parsing in a single
function corresponding to the command line tool.

Cheers,

Loris

-- 
This signature is currently under construction.