github.com/hoffmann Peter Hoffmann on Stackoverflow @peterhoffmann on twitter Peter Hoffmann on Facebook Contact me per email Subscribe to Atom Feed

Peter Hoffmann

Software Engineer
prev page next page

Argscript - a port of werkzeug script to argparse

Posted on June 10, 2012
#python

argscript is a port of werkzeug.script to argparse. Argscript generates a an argparse command line parser from the function definitions of a script.

An action is a function in the same module starting with action_ which takes a number of arguments where every argument has a default. The type of the default value specifies the type of the argument. Arguments can then be passed by using --name=value from the shell. werkzeug.script

Basic Usage is the same as werkzeug.script:

#!/usr/bin/env python
# -*- coding: utf-8 -*-
"""Docstring for test script"""

import argscript

# actions go here
def action_foo(arg1='test'):
    """doc for action foo

    arg1 -- first argument
    """
    print 'action_foo called with argument arg1: %s' % arg1 

def action_bar(msg='', times=1):
    """doc for action bar

    msg -- a message
    times -- number 
    """
    print 'action_bar called with arguments msg: %s, times: %s' %(msg, times)


if __name__ == '__main__':
    argscript.run()

Now you can run the script with the -h parameter to show a basic help. The docstring from the test.py script is reused in the help message.

$ ./test.py -h
usage: test.py [-h] {foo,bar} ...

Docstring for test script

positional arguments:
  {foo,bar}

optional arguments:
  -h, --help  show this help message and exit

To get the help message for a particular action call the script with the action name and the -h parameter:

$ ./test.py bar -h
usage: test.py bar [-h] [--msg MSG] [--times TIMES]

doc for action bar

optional arguments:
  -h, --help     show this help message and exit
  --msg MSG      a message
  --times TIMES  number

Again the function docstring is reuesed in the help message. If you specify a description for the arguments in the doc string (variable -- doc), they are reuesed too.

Now you can run the script with the action name and the parameters, and the action function will be called with them. If you obmit a parameter, the default value will be used to call the function.

$ ./test.py bar --msg='Hello World' --times=4

action_bar called with arguments msg: Hello World, times: 4

Installation

You can either install the development version from github:

git clone git@github.com:hoffmann/argscript.git
cd argscript
sudo python setup.py install

or install it from pypi.python.org:

pip install argscript