Glider Days

glider_days.py

#!/usr/bin/env python
'''
glider_days.py

Determines the glider days for a thredds catalog
'''

from dateutil.parser import parse
from datetime import datetime
from thredds_crawler.crawl import Crawl
from netCDF4 import Dataset
from collections import defaultdict
import sys
import pytz
import csv

utc = pytz.utc

class GliderDays:

    def __init__(self, url):
        self.institutions = defaultdict(int)
        self.url = url

    def parse_catalog(self):
        rows = []
        self.crawler = Crawl(self.url)
        rows.append(['institution', 'url', 'start', 'end', 'seconds'])
        for dataset in self.crawler.datasets:
            error = ''
            try:
                with DatasetRecord(dataset) as dataset_record:
                    institution,url,start,end,seconds = dataset_record.parse_dataset()
                    self.institutions[institution] += seconds
                rows.append([institution, url, start, end, seconds])
            except Exception as e:
                print e.message
        return rows

class DatasetRecord:
    def __init__(self, dataset):
        self.services = { s['name'] : s for s in dataset.services }
        self.nc = None

    def __enter__(self):
        self.url = self.services['odap']['url']
        print "Parsing",self.url
        self.nc = Dataset(self.url)
        return self

    def __exit__(self, type, value, traceback):
        self.nc.close()
        self.nc = None

    def get_seconds(self, start, end):
        i_s = start
        i_e = end

        # Check the year intersections
        if start > datetime(2015,1,1, tzinfo=utc):
            return 0
        if end < datetime(2014,1,1, tzinfo=utc):
            return 0
        if(datetime(2014,1,1, tzinfo=utc) - start).total_seconds() > 0:
            start = datetime(2014,1,1, tzinfo=utc)
        if(end - datetime(2015,1,1, tzinfo=utc)).total_seconds() > 0:
            end = datetime(2015,1,1, tzinfo=utc)
        delta = end - start
        seconds = delta.total_seconds()
        return seconds

    def parse_dataset(self):
        end = parse(self.nc.time_coverage_end)
        start = parse(self.nc.time_coverage_start)
        seconds = self.get_seconds(start, end)
        return self.nc.institution,self.url,start,end,seconds

def main(args):
    '''
    Determines the breakdown of glider days per institution
    '''
    url = args.url
    glider_days = GliderDays(url)
    rows = glider_days.parse_catalog()
    if args.output:
        with open(args.output, 'wb') as csvfile:
            csvwriter = csv.writer(csvfile)
            for row in rows:
                csvwriter.writerow(row)

    for institution in glider_days.institutions:
        if args.float:
            print "%s: %s" % (institution, glider_days.institutions[institution] / (3600 * 24.))
        else:
            print "%s: %s" % (institution, glider_days.institutions[institution] / (3600 * 24))


    return 0

if __name__ == '__main__':
    from argparse import ArgumentParser
    parser = ArgumentParser(description=main.__doc__)
    parser.add_argument('url', help='Catalog Url')
    parser.add_argument('-f', '--float', action='store_true', help='Using Floating Point')
    parser.add_argument('-o','--output',help='CSV Output')
    args = parser.parse_args()
    retval = main(args)
    sys.exit(0)