volkanic 0.6.0

access config and CLI easily and elegantly

volkanic

Interface with config files and shell prompts easily and elegantly.

To install (add sudo if necessary)

python3 -m pip install volkanic

Python version requirement (plan)

0.5.0   Python 3.5+
0.6.0   Python 3.6+
0.7.0   Python 3.7+
0.8.0   Python 3.8+
0.9.0   Python 3.9+

GlobalInterface and config file

Example:

GlobalInterface is defined in example/environ.py as:

import volkanic


class GlobalInterface(volkanic.GlobalInterface):
    # you should always define `package_name`
    package_name = 'example'

Configuration file config.json5:

{
    "upstram_prefix": "http://127.0.0.1:9100",
    "sqlite": "/data/local/example/db.sqlite"
}

This config.json5 is at one of the follow locations:

• Under your project directory in a development enviornment
• ~/.example/config.json5
• /etc/example/config.json5
• /example/config.json5

Access config:

>>> from example.environ import GlobalInterface 
>>> gi = GlobalInterface()  # note that GlobalInterface is a sington class
>>> print(gi.conf)
{'upstram_prefix': 'http://127.0.0.1:9100', 'sqlite': '/data/local/example/db.sqlite'}

Note that GlobalInterface is a singlon class, which means that GlobalInterface() will always return the same object:

>>> GlobalInterface() is GlobalInterface()
True

The recommended usage of GlobalInterface() is to create instanciate it at the top each module:

from example.environ import GlobalInterface  # noqa
from example.tools import your_funny_tool  # noqa

gi = GlobalInterface()


def find_funny_things():
    url = gi.conf['upstram_prefix'] + '/funny-api'
    path = gi.under_package_dir('asset/funny.json')
    # more code here ...

---

Accessories

List sub-commands

$ volk
availabe commands:
- a
- o
- runconf
- where

Locate a Python package directory with volk where:

$ volk where requests
requests	/usr/local/lib/python3.6/site-packages/requests

You can open a file or URL with default application with volk o.

To open current directory with default file manager (Finder / explorer.exe / ...)

$ volk o .

Show sys.argv:

$ volk a \; "hello world" hello python
0	'/usr/local/bin/volk'
1	'a'
2	';'
3	'hello world'
4	'hello'
5	'python'

---

Sub-command protocal

Say you have a package named mypkg

mypkg/
├── MANIFEST.in
├── docs/
├── mypkg/
│    ├── __init__.py
│    ├── algors.py
│    ├── formatters.py
│    ├── main.py
│    └── parsers.py
├── requirements.txt
├── setup.py
└── tests/

In one of your functional modules, e.g. mypkg/mypkg/formatter.py, provide a entry function which takes exactly 2 arguments:

import argparse


def process_file(path):
    # actual code here
    return


def run(prog=None, args=None):
    desc = 'human readable formatter'
    parser = argparse.ArgumentParser(prog=prog, description=desc)
    add = parser.add_argument
    add('-i', '--input-file', help='path to your input file')
    ns = parser.parse_args(args)
    process_file(ns.input_file)

Sub-command registry in mypkg/mypkg/main.py:

import volkanic

commands = {
    "fmt": "mypkg.formatter",
    "yml": "mypkg.parsers:run_yml_parser",
    "ini": "mypkg.parsers:run_ini_parser",
}
registry = volkanic.CommandRegistry(commands)

Note that mypkg.formatter is a shorthand for mypkg.formatter:run.

Configure top level command in mypkg/setup.py:

from setuptools import setup

setup(
    name="mypkg",
    entry_points={"console_scripts": ["mycmd = mypkg.main:registry"]},
    # more arguments here
)

Install package mypkg or link with python3 setup.py develop.

Now you have command mycmd:

$ mycmd
availabe commands:
- fmt
- ini
- yml

Run with sub-command fmt:

$ mycmd fmt -h