JMV3.0 parser

jmv2json.py

#!/usr/bin/python3
from datetime import datetime
from datetime import timedelta
import json
import sys

class JVMParser:
	def parse_header(self, line, result):
		row = tuple(filter(lambda a: a != '', line[0].split(' ')))
		result['issued time'] = datetime.strptime(row[5] + 'GMT', '%y%m%d%H%M%S%Z').isoformat()

		row = tuple(filter(lambda a:a!='', line[1].split(' ')))
		result['title'] = 'Tropical Stom %s (%s) Warning #%s'%(row[1], row[2], 22)
		result['number'] = row[1]
		result['name'] = row[2]
		result['time'] = datetime.strptime(row[0] + 'GMT', '%Y%m%d%H%M%Z')
		return (line[2:], result)
	
	def parse_forcast(self, lines, result):
		def windarea_iterator(row, result):
			if (len(row) == 0):
				return result
			area = {}
			area['windspeed'] = int(row[0][1:])
			area['radius'] = {}
			area['radius'][row[2]] = int(row[1])
			area['radius'][row[5]] = int(row[4])
			area['radius'][row[8]] = int(row[7])
			area['radius'][row[11]] = int(row[10])
			result.append(area)
			return windarea_iterator(row[13:], result)		
			

		def iterator(lines):
			row = tuple(filter(lambda a: a != '', lines[0].split(' ')))
			if (row[0].find('AMP') == 0):
				return (lines, result)
			r = {}
			r['time'] = (result['time'] + timedelta(hours=int(row[0][1:]))).isoformat()
			r['position'] = (row[1], row[2])
			r['windspeed'] = int(row[3])
			if (len(row) > 4):
				r['windarea'] = []
				r['windarea'].append(windarea_iterator(row[4:], []))
			result['forcasts'].append(r)
			return iterator(lines[1:])
		
		result['forcasts'] = []
		return iterator(lines)

	def skip(self, lines, result):
		for i in range(len(lines)):
			row = tuple(filter(lambda a: a != '', lines[i].split(' ')))
			if (len(row[0]) == 10 and row[0].isnumeric()):
				return (lines[i:], result)
			

	def parse_remarks(self, lines, result):
		parse_pos = lambda a: '%.1f%s'%(int(a[:-1])/10, a[-1])

		def iterator(lines, result):
			row = tuple(filter(lambda a: a != '', lines[0].split(' ')))
			if (row[0].find('NNNN') >= 0):
				return (lines[1:], result)

			r = {}
			r['time'] = datetime.strptime(row[0][2:], '%y%m%d%H').isoformat()
			r['position'] = (parse_pos(row[1][0:4]), parse_pos(row[1][5:]))
			r['windspeed'] = int(row[2])
			result['route'].append(r)
			return iterator(lines[1:], result)

		result['route'] = []
		return iterator(lines[1:],result)

	def parse(self, filename):
		lines = []
		with open(filename) as f:
			for line in f:
				lines.append(line[:-1])
		self.result = {}
		lines, result = self.parse_header(tuple(lines[1:]), {})
		lines, result = self.parse_forcast(lines, result)
		lines, result = self.skip(lines, result)
		lines, result = self.parse_remarks(lines, result)
		del result['time']
		return result
	



def usage(argv):
	print('Usage: %s filename'%argv[0])

def main(argv):
	if (len(argv) != 2):
		usage(argv)
		sys.exit(-1)
	p = JVMParser()
	print(json.dumps(p.parse(argv[1])))

if (__name__ == '__main__'):
	main(sys.argv)