#! /usr/bin/env python

# imp is a pure python module
import imp
# numpy is an external library
import numpy
# Constants
IO_ERROR = 1

def parse_inputs(inputfilename):
    """Parse inputs to program from the given file."""
    try:
        # http://docs.python.org/library/imp.html#imp.load_source
        parameters = imp.load_source("parameters", inputfilename)
    except IOError as err:
        print >>sys.stderr, '%s: %s' % (str(err), inputfilename)
        print >>sys.stderr, 'The specified input file was not found - exiting'
        sys.exit(IO_ERROR)
    return parameters

def main():
    """In this example, parse an input file and print some of its contents."""
    parameters = parse_inputs('input.py')

    print 'a:',
    print parameters.a,
    print type(parameters.a)

    print 'b:',
    for i in parameters.b:
        # The comma will add a space between characters
        print i,
    print

    print 'c:',
    for i in parameters.c:
        print i,
    print


if __name__ == '__main__':
    main()