Getting started

Installation

Install the library with pip:

$ pip install confit

A simple example

Confit only abstracts the boilerplate code related to configuration and leaves the rest of your code unchanged.

Here is an example:

script.py

import datetime
+ from confit import Cli, Registry, RegistryCollection

+ app = Cli(pretty_exceptions_show_locals=False)

+ class RegistryCollection(:
+     factory = Registry(("test_cli", "factory"), entry_points=True)

+ @registry.factory.register("submodel")
class SubModel:
    # Type hinting is optional but recommended to benefit for argument casting !
    def __init__(self, value: float, desc: str = ""):
        self.value = value
        self.desc = desc


+ @registry.factory.register("bigmodel")
class BigModel:
    def __init__(self, date: datetime.date, submodel: SubModel):
        self.date = date
        self.submodel = submodel


+ @app.command(name="script", registry=registry)
def func(modelA: BigModel, modelB: BigModel, other: int, seed: int):
    assert modelA.submodel is modelB.submodel
    assert modelA.date == datetime.date(2010, 10, 10)
    print("Other:", other)

+ if __name__ == "__main__":
+     app()

Create a new config file

INI syntaxYAML syntax

config.cfg

# CLI sections
[script]
modelA = ${modelA}
modelB = ${modelB}

# CLI common parameters
[modelA]
@factory = "bigmodel"
date = "2010-10-10"

[modelA.submodel]
@factory = "submodel"
value = 12

[modelB]
date = "2003-04-05"
submodel = ${modelA.submodel}

and run the following command from the terminal

$ python script.py --config config.cfg --seed 42

config.yaml

script:
  modelA: ${modelA}
  modelB: ${modelB}

modelA:
  "@factory": "bigmodel"
  date: "2010-10-10"

  submodel:
    "@factory": "submodel"
    value: 12

modelB:
  date: "2003-04-05"
  submodel: ${modelA.submodel}

and run the following command from the terminal

$ python script.py --config config.yaml --seed 42

Naming

To use the name of your config path (e.g. config-expe-2 if the configuration file is named config-expe-2.cfg in the configuration (after resolution), simply mention name = None under the section which title was provided at @app.command(name=<section-title>)

Multiple configurations

You can pass multiple configuration files by repeating the --config option. Configuration will be merged in order.

You can still call the function method from your code, but now also benefit from argument validation !

from script import func, BigModel, SubModel

# To seed before creating the models
from confit.utils.random import set_seed

seed = 42
set_seed(seed)

submodel = SubModel(value=12)
# BigModel will cast date strings as datetime.date objects
modelA = BigModel(date="2003-02-01", submodel=submodel)
modelB = BigModel(date="2003-04-05", submodel=submodel)
func(
    modelA=modelA,
    modelB=modelA,
    seed=seed,
)