geoindex.py 文件源码

def wmo_importer(url='http://tgftp.nws.noaa.gov/data/nsd_bbsss.txt'):
    if PY2:
        delimiter = b';'
        data = urlopen(url)
    else:
        delimiter = ';'
        import codecs
        data = codecs.iterdecode(urlopen(url), 'utf-8')
    reader = csv.reader(data, delimiter=delimiter, quoting=csv.QUOTE_NONE)

    def geo_normalize(value):
        # recognize NSEW or undefined (which is interpreted as North)
        orientation = value[-1]
        sign = -1 if orientation in 'SW' else 1
        coords = value if orientation not in 'NEWS' else value[:-1]
        coords += '-0-0'  # ensure missing seconds or minutes are 0
        degrees, minutes, seconds = map(float, coords.split('-', 3)[:3])
        return sign * (degrees + (minutes / 60) + (seconds / 3600))

    not_airport = '----'

    for row in reader:
        name = row[0] + row[1] if row[2] == not_airport else row[2]
        yield name, geo_normalize(row[8]), geo_normalize(row[7])


# dependence between hashtag's precision and distance accurate calculating
# in fact it's sizes of grids in km