Delfick App

A framework to simplify and remove duplication when creating a new application. It is opinionated in nature and aims to be declarative.

Getting Started

The most basic example of usage would look something like:

#!/usr/bin/env python
from delfick_app import App

class MyApp(object):
    def start(self, cli_args):
        print "hello world"

class Main(App):
    def execute(self, args_obj, args_dict, extra_args, logging_handler):
        """Start your app!"""

main = Main.main
if __name__ == "__main__":

This will give you a usage that looks like:

$ ./ [–verbose|–silent|–debug]

Where –verbose and –debug show more logs and –silent silences all the logs.

Your logs will be colourful and your mainline will catch and print any DelfickError exceptions nicely to the terminal.

Advanced Usage

from my_app import MyApp, VERSION

from delfick_app import App
import logging

class Main(App):

    # Setting both VERSION and boto_useragent_name
    # Will change boto's useragent to include {name}/{VERSION}
    # Not setting them means boto's useragent is unchanged
    boto_useragent_name = "myapp"

    # Cli options for configuration special cli options
    cli_categories = ['app']
    cli_description = "My amazing app"
    cli_environment_defaults = {"CONFIG_LOCATION": ("--config", './config.yml')}
    cli_positional_replacements = [('--task', 'list_tasks'), '--environment']

    def execute(self, args_obj, args_dict, extra_args, logging_handler):
        # Optionally set the logging theme between 'light' and 'dark'
        self.setup_logging_theme(logging_handler, colors="dark")

        # Do what is necessary to start the app
        app = MyApp()

    def setup_other_logging(self, args, verbose=False, silent=False, debug=False):
        logging.getLogger("boto").setLevel([logging.CRITICAL, logging.ERROR][verbose or debug])

    def specify_other_args(self, parser, defaults):
            , help = "The task to execute"
            , **defaults['--task']

            , help = "the environment to use"
            , **defaults["--environment"]

            , help = "The configuration to use"
            , **defaults["--config"]

main = Main.main
if __name__ == '__main__':

With the above configuration, the following three usages are equivalent:

$ ./ some_task dev --config ./config.yml

$ ./ --task some_task --environment dev --config ./config.yml

$ APP_CONFIG=./config.yml ./ some_task dev


Just use pip:

$ pip install delfick_app


0.9.7 - 25 August 2018
  • Adding –json-console-logs option which will do logs as json lines to the console
No change log kept before this point


Run the following:

$ mkvirtualenv delfick_app
$ workon delfick_app
$ pip install -e .
$ pip install -e ".[tests]"

To install delfick_app and it’s dependencies.

Then to run the tests:

$ ./