climatecontrol 0.2.6

Python library for loading app configurations from files and/or namespaced environment variables

CLIMATECONTROL

CLIMATECONTROL controls your apps configuration environment. It is a Python library for loading app configurations from files and/or namespaced environment variables.

Install

pip install climatecontrol

Note that versions 0.2.4 and below will probably not work with python 3.5.2 and below. Default 3.5 branch should work fine though.

Usage

Set some environment variables in your shell

export MY_APP_SECTION1_SUBSECTION1=test1
export MY_APP_SECTION2_SUBSECTION2=test2
export MY_APP_SECTION2_SUBSECTION3=test3

Then use them in your python modules:

from climatecontrol.settings_parser import Settings
settings_map = Settings(prefix='MY_APP')
print(dict(settings_map))

{
    'section1': {
        'subsection1': 'test1'
    },
    'section2': {
        'subsection2': 'test2',
        'subsection3': 'test3'
    }
}

In case you want to update your settings or your environment variables have changed and you want to reload them, the update method will reload your settings:

import os
os.environ['MY_APP_SECTION2_NEW_ENV_VAR'] = 'new_env_data'
settings_map.update()
print(dict(settings_map))

{
    'section1': {
        'subsection1': 'test1'
    },
    'section2': {
        'subsection2': 'test2',
        'subsection3': 'test3',
        'new_env_var': 'new_env_data'
    }
}

Now you’ve noticed that you want more complex configurations and have settings variables with underscores all over the place. For this situation you can escape the section - splitting mechanism by using the splitting character twice in your env variables:

settings_map = Settings(prefix='MY_APP', max_depth=3)
print(dict(settings_map))

{
    'section1': {
        'subsection1': 'test1'
    },
    'section2': {
        'subsection2': 'test2',
        'subsection3': 'test3',
        'new': {
            'env': {
                'var': 'new_env_data'
            }
        }
    }
}

# That was ugly... we wanted something else
del os.environ['MY_APP_SECTION2_NEW_ENV_VAR']

# Notice the __ in the variable:
os.environ['MY_APP_SECTION2_NEW_ENV__VAR'] = 'new_env_data'

# Now let's look again
settings_map.update()
print(dict(settings_map))

{
    'section1': {
        'subsection1': 'test1'
    },
    'section2': {
        'subsection2': 'test2',
        'subsection3': 'test3',
        'new': {
            'env_var': 'new_env_data'
        }
    }
}

Settings file support

If you don’t want to use an environment variable for every single setting and want to put your settings in a single file instead you can to this as well. Settings files need to be in toml format right now.

export MY_APP_SETTINGS_FILE=./my_settings_file.toml

The file could look like this:

[section1]
subsection1 = "test1"

[section2]
subsection2 = "test2"
subsection3 = "test3"

Command line support using click

The click library is a great tool for creating command line applications. If you don’t want to have to use an environment to set your configuration file. Write your command line application like this:

import click

@click.command()
@settings_map.click_settings_file_option()
def cli():
   print(dict(settings_parser))

save it to a file like “cli.py” and then call it after installing click:

pip install click
python cli.py --settings ./my_settings_file.toml

whithout needing to set any env vars.