openfoam_project/post_process/animate/__main__.py

import argparse

parser = argparse.ArgumentParser(
    description='Animate the results from OpenFoam'
)
parser.add_argument('var', type=str,
    help='OpenFoam variable to display')
parser.add_argument('-c', '--config', type=str,
    default='config.ini',
    help='Configuration file (default config.ini)')

args = parser.parse_args()

if args.var == 'alpha.water':
    import alpha_water
    alpha_water.animate(args.config)