Amersham

Amersham: The name of a London Underground station which alliterates with "argument parser"

Motivation

Every CLI application wants two things:

1. Sanitized user input
2. Descriptive usage and help messages

Amersham implements both with minimal boilerplate.

Quick Start

Install

pip3 install amersham

Import

import sys

from amersham import Parser

Create a parser and command

parser = Parser("app")

@parser.command()
def command(parameter, flag = None):
    pass

Run the parser

if __name__ == "__main__":
    parser.run(sys.argv[1:])

Run your program

user:~$ python3 app.py --help
usage
  app.py [--help] [--flag] PARAMETER

flags
  --help  -h  displays this message
  --flag

parameters
  PARAMETER  string

Advanced Usage

More Descriptive Help Messages

Add some context to our command and arguments

overrides = {
    "description": "a command",

    "parameter": {
        "description": "a parameter",
    },
    "flag": {
        "description": "a flag",
        "alias": "f",
    }
}

@parser.command(**overrides)
def command(parameter, flag = ""):
    pass

And see the results

user:~$ python3 app.py --help
usage
  app.py [--help] [--flag] PARAMETER

description
  a command

flags
  --help  -h          displays this message
  --flag      string  a flag

parameters
  PARAMETER  string  a parameter