Dynamic entries in a settings module

Question

I'm writing a package that imports audio files, processes them, plots them etc., for research purposes. At each stage of the pipeline, settings are pulled from a settings module as shown below.

I want to be able to update a global setting like MODEL_NAME and have it update in any dicts containing it too.

settings.py

MODEL_NAME = 'Test1'
DAT_DIR = 'dir1/dir2/'
PROCESSING = {
    "key1":{
        "subkey2":0,
        "subkey3":1
    },
    "key2":{
        "subkey3":MODEL_NAME
    }
}

run.py

import settings as s
wavs = import_wavs(s.DAT_DIR)
proc_wavs = proc_wavs(wavs,s.PROCESSING)

Some of the settings dicts I would like to contain MODEL_NAME, which works fine. The problem arises when I want to change MODEL_NAME during runtime. So if I do:

import settings as s
wavs = import_wavs(s.DAT_DIR)
s.MODEL_NAME='test1'
proc_wavs1 = proc_wavs(wavs,s.PROCESSING)
s.MODEL_NAME='test2'
proc_wavs2 = proc_wavs(wavs,s.PROCESSING)

But obviously both the calls so s.PROCESSING will contain the MODEL_NAME originally assigned in the settings file. What is the best way to have it update?

Possible solutions I've thought of:

• Store the variables as a mutable type, then update it e.g.:

  s.MODEL_NAME[0] = ["test1"]
  # do processing things
  s.MODEL_NAME[0] = ["test2"]
  

• Define each setting category as a function instead, so it is rerun on each call e.g.:

  MODEL_NAME = 'test1' ..
  
  def PROCESSING():
     return {
         "key1":{
             "subkey2":0,
             "subkey3":1
         },
         "key2":{
             "subkey3":MODEL_NAME
         }
     }
  

  Then

  s.MODEL_NAME='test1'
  proc_wavs1 = proc_wavs(wavs,s.PROCESSING())
  s.MODEL_NAME='test2'
  proc_wavs1 = proc_wavs(wavs,s.PROCESSING())
  

  I thought this would work great, but then it's very difficult to change any entries of the functions during runtime eg if I wanted to update the value of subkey2 and run something else.

Other thoughts maybe a class with an update method or something, does anyone have any better ideas?

Answer 1

You want to configure generic and specific settings structured in dictionaries for functions that perform waves analysis.

Start by defining a settings class, like :

class Settings :

  data_directory = 'path/to/waves'

  def __init__(self, model):         
     self.parameters= {
       "key1":{
           "subkey1":0,
           "subkey2":0
       },
       "key2":{
           "subkey1":model
       }
     }

# create a new class based on model1
s1 = Settings('model1')
# attribute values to specific keys
s1.parameters["key1"]["subkey1"] = 3.1415926
s1.parameters["key1"]["subkey2"] = 42
# an other based on model2
s2 = Settings('model2')
s2.parameters["key1"]["subkey1"] = 360
s2.parameters["key1"]["subkey2"] = 1,618033989
# load the audio
wavs = openWaves(Settings.data_directory)
# process with the given parameters
results1 = processWaves(wavs,s1)
results2 = processWaves(wavs,s2)