python-config-parser

python-config-parser

python-config-parser lets you create runtime configuration objects using json or yaml files.

MAIN FEATURES

• Declarative configurations without using .ini files
• Access using OOP or subscriptable, which means that you can iterate the config object items
• Runtime validation using schema
• Automatic environment variables interpolation
• Automatic parser selecting using config file extension

HOW TO INSTALL

Use pip to install it.

pip install python-config-parser

HOW TO USE

By default, the config file will look for any of the following config files in the config directory: config.json/config.yaml/config.yml. You can change the config directory and or config file according to your preference (assuming your current directory).

from pyconfigparser import configparser

configparser.get_config(CONFIG_SCHEMA, config_dir='your_config_dir_path', file_name='your_config_file_name')

Schema validation

You may or not use schema validation. If you want to use it, it will validate and apply rules to the whole config object before returning it. If you choose to not use it, it won't validate the config object before returning it, and it may generate runtime access inconsistencies. How to use schema

from schema import Use, And

SCHEMA_CONFIG = {
    'core': {
        'logging': {
            'format': And(Use(str), lambda string: len(string) > 0),
            'date_fmt': And(Use(str), lambda string: len(string) > 0),
            'random_env_variable': str
        },
        'allowed_clients': [{
                'ip': str, # <- Here you can use regex to validate the ip format
                'timeout': int
            }
        ]
    }
}

The config.yml file

core:
  random_env_variable: ${RANDOM_ENV_VARIABLE}
  logging:
    format: "[%(asctime)s][%(levelname)s]: %(message)s"
    date_fmt: "%d-%b-%y %H:%M:%S"
  allowed_clients:
  - ip: 192.168.0.10
    timeout: 60
  - ip: 192.168.0.11
    timeout: 100

A json config file would be something like:

{
  "core": {
    "random_env_variable": "${RANDOM_ENV_VARIABLE}",
    "logging": {
      "format": "[%(asctime)s][%(levelname)s]: %(message)s",
      "date_fmt": "%d-%b-%y %H:%M:%S"
    },
    "allowed_clients": [
      {
        "ip": "192.168.0.10",
        "timeout": 60
      },
      {
        "ip": "192.168.0.11",
        "timeout": 100
      }
    ]
  }
}

The config instance

from pyconfigparser import configparser, ConfigError
import logging

try:
    config = configparser.get_config(SCHEMA_CONFIG)  # <- Here I'm using that SCHEMA_CONFIG we've already declared
except ConfigError as e:
    print(e)
    exit()

# to access your config you just need to:

fmt = config.core.logging.format #at this point I'm already using the config variables
date_fmt = config['core']['logging']['date_fmt'] # here subscriptable access

logging.getLogger(__name__)

logging.basicConfig(
    format=fmt,
    datefmt=date_fmt,
    level=logging.INFO
)

# the list of object example:

for client in config.core.allowed_clients:
    print(client.ip)
    print(client.timeout)
    
# You can also iterate objects, but instead of giving the property it'll give you the property's name
# And then you can access the values by subscriptale access
for logging_section_attr_key in config.core.logging:
    print(config.core.logging[logging_section_attr_key])

# Accessing the environment variable already resolved
print(config.random_env_variable)

Assuming you've already created the first Config's instance this instance will be cached inside Config class, so after this first creation you just need to re-invoke Config.get_config() without any argument

from pyconfigparser import configparser

config = configparser.get_config()

You can also disable this caching behavior

from pyconfigparser import configparser

configparser.hold_an_instance = False

Environment Variables Interpolation

If the process does not find a value already set to your env variables It will raise a ConfigError. But you can disable this behavior, and the parser will set None to these unresolved env vars

from pyconfigparser import configparser

configparser.ignore_unset_env_vars = True
config = configparser.get_config()

CONTRIBUTE

Fork https://github.com/BrunoSilvaAndrade/python-config-parser/ , create commit and pull request to develop.