def parse_args(argv):
''' Parse an array of command-line options into a argparse.Namespace '''
parser = argparse.ArgumentParser(
description='Simulating small waves on the surface of a small planet.',
formatter_class=argparse.ArgumentDefaultsHelpFormatter)
parser.add_argument('-n',
type=int,
default=200,
help='Size of simulation grid; an n x n grid')
parser.add_argument('--decay',
default='1 week',
help='The half-life of a wave')
parser.add_argument('--gravity',
type=float,
default=9.8e-4,
help='The planet\'s gravity, in metres per second')
parser.add_argument('--width',
default='100km',
help=('Circumference of the planet, travelling '
'east-west'))
parser.add_argument('--height',
default='100km',
help=('Circumference of the planet, travelling '
'north-south'))
parser.add_argument('--depth',
default='4km',
help='Average depth of the planet\'s ocean')
parser.add_argument('--time-per-frame',
default='1 hour',
help=('How much planetary time should pass in each '
'frame of animation'))
parser.add_argument('--frames-per-drop',
type=int,
default=100,
help=('On average, how many frames before a new drop '
'of water is created'))
parser.add_argument('--maximum-speed',
type=float,
default=0.003,
help=('For colouring the visualisation: the speed '
'that should correspond to the lightest colour'))
parser.add_argument('-v',
'--debug',
action='store_true',
help='Verbose logging')
args = parser.parse_args(argv[1:])
# parse human-readable unts
args.seconds_per_frame = parse_timespan(args.time_per_frame)
args.h_background = parse_length(args.depth)
width = parse_length(args.width)
height = parse_length(args.height)
args.drag = 1 / parse_timespan(args.decay)
# set dx and dy
args.dx = width / args.n
args.dy = height / args.n
return args
def test_parse_length(self):
self.assertEqual(0, humanfriendly.parse_length('0m'))
self.assertEqual(42, humanfriendly.parse_length('42'))
self.assertEqual(42, humanfriendly.parse_length('42m'))
self.assertEqual(1000, humanfriendly.parse_length('1km'))
self.assertEqual(0.153, humanfriendly.parse_length('15.3 cm'))
self.assertEqual(1e-02, humanfriendly.parse_length('1cm'))
self.assertEqual(1e-03, humanfriendly.parse_length('1mm'))
self.assertEqual(1e-09, humanfriendly.parse_length('1nm'))
self.assertRaises(humanfriendly.InvalidLength, humanfriendly.parse_length, '1z')
self.assertRaises(humanfriendly.InvalidLength, humanfriendly.parse_length, 'a')
def test_parse_length(self):
"""Test :func:`humanfriendly.parse_length()`."""
self.assertEqual(0, humanfriendly.parse_length('0m'))
self.assertEqual(42, humanfriendly.parse_length('42'))
self.assertEqual(42, humanfriendly.parse_length('42m'))
self.assertEqual(1000, humanfriendly.parse_length('1km'))
self.assertEqual(0.153, humanfriendly.parse_length('15.3 cm'))
self.assertEqual(1e-02, humanfriendly.parse_length('1cm'))
self.assertEqual(1e-03, humanfriendly.parse_length('1mm'))
self.assertEqual(1e-09, humanfriendly.parse_length('1nm'))
self.assertRaises(humanfriendly.InvalidLength, humanfriendly.parse_length, '1z')
self.assertRaises(humanfriendly.InvalidLength, humanfriendly.parse_length, 'a')
def print_parsed_length(value):
"""Parse a human readable length and print the number of metres."""
output(parse_length(value))
def print_parsed_length(value):
"""Parse a human readable length and print the number of metres."""
print(parse_length(value))
