an example of getting configuration information into a file

example in use on the command line

$ python t0.py --help
usage:
t0.py [OPTIONS]...
 

OPTIONS:
  --admin.conf
    the pathname of the config file (path/filename)

  --admin.dump_conf
    a pathname to which to write the current config
    (default: )

  --admin.expose_secrets
    should options marked secret get written out or hidden?
    (default: False)

  --admin.print_conf
    write current config to stdout (json, ini, conf)

  --admin.strict
    mismatched options generate exceptions rather than just warnings
    (default: False)

  --help
    print this

  --planets.mercury.mass
    mass
    (default: 0)

  --planets.mercury.x
    x
    (default: 100)

  --planets.mercury.x_velocity
    x_velocity
    (default: 0)

  --planets.mercury.y
    y
    (default: 100)

  --planets.mercury.y_velocity
    y_velocity
    (default: 0)

  --planets.venus.mass
    mass
    (default: 0)

  --planets.venus.x
    x
    (default: 200)

  --planets.venus.x_velocity
    x_velocity
    (default: 0)

  --planets.venus.y
    y
    (default: 200)

  --planets.venus.y_velocity
    y_velocity
    (default: 0)

$ python t0.py --planets.venus.mass=83 --planets.mercury.mass=17
17
17
17
New Planet: mercury
    mass: 17
    x: 100
    x_velocity: 0
    y: 100
    y_velocity: 0
New Planet: venus
    mass: 83
    x: 200
    x_velocity: 0
    y: 200
    y_velocity: 0

$ python t0.py --planets.venus.mass=45 --planets.mercury.mass=3  --admin.dump_conf=solarsystem.ini 

$ cat  solarsystem.ini
[planets]

    [[mercury]]

        # mass
        mass=3

        # x
        #x=100

        # x_velocity
        #x_velocity=0

        # y
        #y=100

        # y_velocity
        #y_velocity=0

    [[venus]]

        # mass
        mass=45

        # x
        #x=200

        # x_velocity
        #x_velocity=0

        # y
        #y=200

        # y_velocity
        #y_velocity=0


$ python t0.py --admin.conf=solarsystem.ini
3
3
3
New Planet: mercury
    mass: 3
    x: 100
    x_velocity: 0
    y: 100
    y_velocity: 0
New Planet: venus
    mass: 45
    x: 200
    x_velocity: 0
    y: 200
    y_velocity: 0

$ python t0.py --admin.conf=solarsystem.ini --planets.mercury.x_velocity=10000 --admin.dump_conf=next_solarsystem.ini

$ python t0.py --admin.conf=next_solarsystem.ini
3
3
3
New Planet: mercury
    mass: 3
    x: 100
    x_velocity: 10000
    y: 100
    y_velocity: 0
New Planet: venus
    mass: 45
    x: 200
    x_velocity: 0
    y: 200
    y_velocity: 0
$ 

t0.py

#!/usr/bin/env  python

# grab the configuration function from the configman module
from configman import configuration

# create structure of nested dicts that define a hierarchy of of
# configuration values that you want available in your program

initial_config = {
    "planets": {
        'mercury': {
            'mass': 0,
            'x': 100,
            'y': 100,
            'x_velocity': 0,
            'y_velocity': 0,
        },
        'venus': {
            'mass': 0,
            'x': 200,
            'y': 200,
            'x_velocity': 0,
            'y_velocity': 0,
        },
    }
}

# tell configman to start your program reading any configuration from the
# commandline, configuration file or environment variables.

config = configuration(initial_config)

# config is now a nested structure of constants that you can access in either
# dotted form like this:
print config.planets.mercury.mass

# or a subscripting form like this
print config["planets"]["mercury"]["mass"]

# or even mixed and matched
print config.planets['mercury'].mass


# you could even use it to create a loop:

class Planet(object):
    def __init__(self, name, **kwargs):
        print "New Planet:", name
        for an_attribute, a_value in sorted(kwargs.iteritems()):
            print "    %s: %s" % (an_attribute, a_value)
            setattr(self,  an_attribute, a_value)


my_solar_system = set()
for planet_name, some_planet_attributes in config.planets.iteritems():
    # take the dict that decscribes the initial configuration of a planet
    # and turn them into arguments for the planet constructor
    new_planet = Planet(planet_name, **some_planet_attributes)
    my_solar_system.add(new_planet)