Break out data fetching operations into routines
[infoex-autowx.git] / infoex-autowx.py
index 3d8762c81b58c97eeecc8af10583a835435801c9..63989b9433aefe0d8523501094264395870a1840 100755 (executable)
@@ -2,14 +2,13 @@
 # -*- coding: utf-8 -*-
 
 """
-InfoEx <-> NRCS Auto Wx implementation
+InfoEx <-> NRCS/MesoWest Auto Wx implementation
 Alexander Vasarab
 Wylark Mountaineering LLC
 
-Version 1.0.0
-
-This program fetches data from an NRCS SNOTEL site and pushes it to
-InfoEx using the new automated weather system implementation.
+This program fetches data from either an NRCS SNOTEL site or MesoWest
+weather station and pushes it to InfoEx using the new automated weather
+system implementation.
 
 It is designed to be run hourly, and it asks for the last three hours
 of data of each desired type, and selects the most recent one. This
@@ -31,7 +30,6 @@ import os
 import sys
 import time
 
-from collections import OrderedDict
 from ftplib import FTP
 from optparse import OptionParser
 
@@ -41,178 +39,319 @@ import zeep
 import zeep.cache
 import zeep.transports
 
-log = logging.getLogger(__name__)
-log.setLevel(logging.DEBUG)
-
-try:
-    from systemd.journal import JournalHandler
-    log.addHandler(JournalHandler())
-except:
-    ## fallback to syslog
-    #import logging.handlers
-    #log.addHandler(logging.handlers.SysLogHandler())
-    # fallback to stdout
-    handler = logging.StreamHandler(sys.stdout)
-    log.addHandler(handler)
-
-parser = OptionParser()
-parser.add_option("--config",
-    dest="config",
-    metavar="FILE",
-    help="location of config file")
-parser.add_option("--dry-run",
-    action="store_true",
-    dest="dry_run",
-    default=False,
-    help="fetch data but don't upload to InfoEx")
-
-(options, args) = parser.parse_args()
-
-config = configparser.ConfigParser(allow_no_value=False)
-
-if not options.config:
-    print("Please specify a configuration file via --config.")
-    sys.exit(1)
-
-config.read(options.config)
-
-log.debug('STARTING UP')
-
-try:
-    infoex = {
-        'host': config['infoex']['host'],
-        'uuid': config['infoex']['uuid'],
-        'api_key': config['infoex']['api_key'],
-        'csv_filename': config['infoex']['csv_filename'],
-        'location_uuid': config['infoex']['location_uuid'],
-        'wx_data': {}, # placeholder key, values to come later
-    }
-
-    data = dict()
-    data['provider'] = config['station']['type']
-
-    if data['provider'] not in ['nrcs', 'mesowest']:
-        print("Please specify either nrcs or mesowest as the station type.")
+__version__ = '2.0.0'
+
+LOG = logging.getLogger(__name__)
+LOG.setLevel(logging.NOTSET)
+
+def get_parser():
+    """Return OptionParser for this program"""
+    parser = OptionParser(version=__version__)
+
+    parser.add_option("--config",
+        dest="config",
+        metavar="FILE",
+        help="location of config file")
+
+    parser.add_option("--log-level",
+        dest="log_level",
+        default=None,
+        help="set the log level (debug, info, warning)")
+
+    parser.add_option("--dry-run",
+        action="store_true",
+        dest="dry_run",
+        default=False,
+        help="fetch data but don't upload to InfoEx")
+
+    return parser
+
+def setup_config(config):
+    """Setup config variable based on values specified in the ini file"""
+    try:
+        infoex = {
+            'host': config['infoex']['host'],
+            'uuid': config['infoex']['uuid'],
+            'api_key': config['infoex']['api_key'],
+            'csv_filename': config['infoex']['csv_filename'],
+            'location_uuid': config['infoex']['location_uuid'],
+            'wx_data': {}, # placeholder key, values to come later
+        }
+
+        data = dict()
+        data['provider'] = config['station']['type']
+
+        if data['provider'] not in ['nrcs', 'mesowest']:
+            print("Please specify either nrcs or mesowest as the station type.")
+            sys.exit(1)
+
+        if data['provider'] == 'nrcs':
+            data['source'] = 'https://www.wcc.nrcs.usda.gov/awdbWebService/services?WSDL'
+            data['station_id'] = config['station']['station_id']
+
+            try:
+                data['desired_data'] = config['station']['desired_data'].split(',')
+            except:
+                # desired_data malformed or missing, setting default
+                data['desired_data'] = [
+                                       'TOBS', # AIR TEMPERATURE OBSERVED (degF)
+                                       'SNWD', # SNOW DEPTH (in)
+                                       'PREC'  # PRECIPITATION ACCUMULATION (in)
+                                       ]
+
+            # XXX: For NRCS, we're manually overriding units for now! Once
+            #      unit conversion is supported for NRCS, REMOVE THIS!
+            if 'units' not in data:
+                data['units'] = 'imperial'
+
+        if data['provider'] == 'mesowest':
+            data['source'] = 'https://api.synopticdata.com/v2/stations/timeseries'
+            data['station_id'] = config['station']['station_id']
+            data['units'] = config['station']['units']
+
+            try:
+                data['desired_data'] = config['station']['desired_data']
+            except:
+                # desired_data malformed or missing, setting default
+                data['desired_data'] = 'air_temp,snow_depth'
+
+            # construct full API URL (sans start/end time, added later)
+            data['source'] = data['source'] + '?token=' + config['station']['token'] + '&within=60&units=' + data['units'] + '&stid=' + data['station_id'] + '&vars=' + data['desired_data']
+
+    except KeyError as e:
+        LOG.critical("%s not defined in %s" % (e, options.config))
+        exit(1)
+    except Exception as exc:
+        LOG.critical("Exception occurred in config parsing: '%s'" % (exc))
+        exit(1)
+
+    # all sections/values present in config file, final sanity check
+    try:
+        for key in config.sections():
+            for subkey in config[key]:
+                if not len(config[key][subkey]):
+                    raise ValueError;
+    except ValueError as exc:
+        LOG.critical("Config value '%s.%s' is empty" % (key, subkey))
+        exit(1)
+
+    return (infoex, data)
+
+def setup_logging(log_level):
+    """Setup our logging infrastructure"""
+    try:
+        from systemd.journal import JournalHandler
+        LOG.addHandler(JournalHandler())
+    except:
+        ## fallback to syslog
+        #import logging.handlers
+        #LOG.addHandler(logging.handlers.SysLogHandler())
+        # fallback to stdout
+        handler = logging.StreamHandler(sys.stdout)
+        LOG.addHandler(handler)
+
+    # ugly, but passable
+    if log_level in [None, 'debug', 'info', 'warning']:
+        if log_level == 'debug':
+            LOG.setLevel(logging.DEBUG)
+        elif log_level == 'info':
+            LOG.setLevel(logging.INFO)
+        elif log_level == 'warning':
+            LOG.setLevel(logging.WARNING)
+        else:
+            LOG.setLevel(logging.NOTSET)
+    else:
+        return False
+
+    return True
+
+def main():
+    """Main routine: sort through args, decide what to do, then do it"""
+    parser = get_parser()
+    (options, args) = parser.parse_args()
+
+    config = configparser.ConfigParser(allow_no_value=False)
+
+    if not options.config:
+        parser.print_help()
+        print("\nPlease specify a configuration file via --config.")
         sys.exit(1)
 
+    config.read(options.config)
+
+    if not setup_logging(options.log_level):
+        parser.print_help()
+        print("\nPlease select an appropriate log level or remove the switch (--log-level).")
+        sys.exit(1)
+
+    (infoex, data) = setup_config(config)
+
+    LOG.debug('Config parsed, starting up')
+
+    # create mappings
+    (fmap, final_data) = setup_infoex_fields_mapping(infoex['location_uuid'])
+    iemap = setup_infoex_counterparts_mapping(data['provider'])
+
+    # override units if user selected metric
+    #
+    # NOTE: to update this, use the fmap<->final_data mapping laid out above
+    #
+    # NOTE: this only 'works' with MesoWest for now, as the MesoWest API
+    #       itself handles the unit conversion; in the future, we will also
+    #       support NRCS unit conversion, but this must be done by this
+    #       program.
+    if data['units'] == 'metric':
+        final_data[fmap['tempPresUnit']] = 'C'
+        final_data[fmap['hsUnit']] = 'm'
+        final_data[fmap['windSpeedUnit']] = 'm/s'
+        final_data[fmap['windGustSpeedNumUnit']] = 'm/s'
+
+    # floor time to nearest hour
+    dt = datetime.datetime.now()
+    end_date = dt - datetime.timedelta(minutes=dt.minute % 60,
+                                       seconds=dt.second,
+                                       microseconds=dt.microsecond)
+    begin_date = end_date - datetime.timedelta(hours=3)
+
+    # get the data
+    LOG.debug("Getting %s data from %s to %s" % (str(data['desired_data']),
+        str(begin_date), str(end_date)))
+
+    time_all_elements = time.time()
+
+    # get the data
     if data['provider'] == 'nrcs':
-        data['source'] = 'https://www.wcc.nrcs.usda.gov/awdbWebService/services?WSDL'
-        data['station_id'] = config['station']['station_id']
-
-        try:
-            desired_data = config['station']['desired_data'].split(',')
-        except:
-            # desired_data malformed or missing, setting default
-            desired_data = [
-                    'TOBS', # AIR TEMPERATURE OBSERVED (degF)
-                    'SNWD', # SNOW DEPTH (in)
-                    'PREC'  # PRECIPITATION ACCUMULATION (in)
-                    ]
-
-    if data['provider'] == 'mesowest':
-        data['source'] = 'https://api.synopticdata.com/v2/stations/timeseries'
-        data['station_id'] = config['station']['station_id']
-        data['units'] = config['station']['units']
-
-        try:
-            desired_data = config['station']['desired_data']
-        except:
-            # desired_data malformed or missing, setting default
-            desired_data = 'air_temp,snow_depth'
-
-        # construct full API URL (sans start/end time, added later)
-        data['source'] = data['source'] + '?token=' + config['station']['token'] + '&within=60&units=' + data['units'] + '&stid=' + data['station_id'] + '&vars=' + desired_data
-
-except KeyError as e:
-    log.critical("%s not defined in %s" % (e, options.config))
-    exit(1)
-except Exception as exc:
-    log.critical("Exception occurred in config parsing: '%s'" % (exc))
-    exit(1)
-
-# all sections/values present in config file, final sanity check
-try:
-    for key in config.sections():
-        for subkey in config[key]:
-            if not len(config[key][subkey]):
-                raise ValueError;
-except ValueError as exc:
-    log.critical("Config value '%s.%s' is empty" % (key, subkey))
-    exit(1)
-
-# INFOEX FIELDS
-#
-# This won't earn style points in Python, but here we establish a couple
-# of helpful mappings variables. The reason this is helpful is that the
-# end result is simply an ordered set, the CSV file. But we still may
-# want to manipulate the values arbitrarily before writing that file.
-#
-# Also note that the current Auto Wx InfoEx documentation shows these
-# keys in a graphical table with the "index" beginning at 1, but here we
-# are sanely indexing beginning at 0.
-fmap = {}                           ; final_data     = [None] * 29
-fmap['Location UUID'] = 0           ; final_data[0]  = infoex['location_uuid']
-fmap['obDate'] = 1                  ; final_data[1]  = None
-fmap['obTime'] = 2                  ; final_data[2]  = None
-fmap['timeZone'] = 3                ; final_data[3]  = 'Pacific'
-fmap['tempMaxHour'] = 4             ; final_data[4]  = None
-fmap['tempMaxHourUnit'] = 5         ; final_data[5]  = 'F'
-fmap['tempMinHour'] = 6             ; final_data[6]  = None
-fmap['tempMinHourUnit'] = 7         ; final_data[7]  = 'F'
-fmap['tempPres'] = 8                ; final_data[8]  = None
-fmap['tempPresUnit'] = 9            ; final_data[9]  = 'F'
-fmap['precipitationGauge'] = 10     ; final_data[10] = None
-fmap['precipitationGaugeUnit'] = 11 ; final_data[11] = 'in'
-fmap['windSpeedNum'] = 12           ; final_data[12] = None
-fmap['windSpeedUnit'] = 13          ; final_data[13] = 'mph'
-fmap['windDirectionNum'] = 14       ; final_data[14] = None
-fmap['hS'] = 15                     ; final_data[15] = None
-fmap['hsUnit'] = 16                 ; final_data[16] = 'in'
-fmap['baro'] = 17                   ; final_data[17] = None
-fmap['baroUnit'] = 18               ; final_data[18] = 'inHg'
-fmap['rH'] = 19                     ; final_data[19] = None
-fmap['windGustSpeedNum'] = 20       ; final_data[20] = None
-fmap['windGustSpeedNumUnit'] = 21   ; final_data[21] = 'mph'
-fmap['windGustDirNum'] = 22         ; final_data[22] = None
-fmap['dewPoint'] = 23               ; final_data[23] = None
-fmap['dewPointUnit'] = 24           ; final_data[24] = 'F'
-fmap['hn24Auto'] = 25               ; final_data[25] = None
-fmap['hn24AutoUnit'] = 26           ; final_data[26] = 'in'
-fmap['hstAuto'] = 27                ; final_data[27] = None
-fmap['hstAutoUnit'] = 28            ; final_data[28] = 'in'
-
-# one final mapping, the NRCS/MesoWest fields that this program supports to
-# their InfoEx counterpart
-iemap = {}
-
-if data['provider'] == 'nrcs':
-    iemap['PREC'] = 'precipitationGauge'
-    iemap['TOBS'] = 'tempPres'
-    iemap['SNWD'] = 'hS'
-elif data['provider'] == 'mesowest':
-    iemap['precip_accum'] = 'precipitationGauge'
-    iemap['air_temp'] = 'tempPres'
-    iemap['snow_depth'] = 'hS'
-
-# floor time to nearest hour
-dt = datetime.datetime.now()
-end_date = dt - datetime.timedelta(minutes=dt.minute % 60,
-                                   seconds=dt.second,
-                                   microseconds=dt.microsecond)
-begin_date = end_date - datetime.timedelta(hours=3)
-
-# get the data
-log.debug("Getting %s data from %s to %s" % (str(desired_data),
-    str(begin_date), str(end_date)))
-
-time_all_elements = time.time()
-
-# NRCS-specific code
-if data['provider'] == 'nrcs':
+        infoex['wx_data'] = get_nrcs_data(begin_date, end_date, data)
+    elif data['provider'] == 'mesowest':
+        infoex['wx_data'] = get_mesowest_data(begin_date, end_date,
+                data)
+
+    LOG.info("Time to get all data : %.3f sec" % (time.time() -
+        time_all_elements))
+
+    LOG.debug("infoex[wx_data]: %s", str(infoex['wx_data']))
+
+    # Now we only need to add in what we want to change thanks to that
+    # abomination of a variable declaration earlier
+    final_data[fmap['Location UUID']] = infoex['location_uuid']
+    final_data[fmap['obDate']] = end_date.strftime('%m/%d/%Y')
+    final_data[fmap['obTime']] = end_date.strftime('%H:%M')
+
+    for elementCd in infoex['wx_data']:
+        if elementCd not in iemap:
+            LOG.warning("BAD KEY wx_data['%s']" % (elementCd))
+            continue
+
+        # CONSIDER: Casting every value to Float() -- need to investigate if
+        #           any possible elementCds we may want are any other data
+        #           type than float.
+        #
+        #           Another possibility is to query the API with
+        #           getStationElements and temporarily store the
+        #           storedUnitCd. But that's pretty network-intensive and
+        #           may not even be worth it if there's only e.g. one or two
+        #           exceptions to any otherwise uniformly Float value set.
+        final_data[fmap[iemap[elementCd]]] = infoex['wx_data'][elementCd]
+
+    LOG.debug("final_data: %s" % (str(final_data)))
+
+    if not write_local_csv(infoex['csv_filename'], final_data):
+        LOG.warning('Could not write local CSV file: %s',
+                    infoex['csv_filename'])
+        return 1;
+
+    if not options.dry_run:
+        upload_csv(infoex['csv_filename'], infoex)
+
+    LOG.debug('DONE')
+    return 0
+
+# data structure operations
+def setup_infoex_fields_mapping(location_uuid):
+    """
+    Create a mapping of InfoEx fields to the local data's indexing scheme.
+
+    INFOEX FIELDS
+    
+    This won't earn style points in Python, but here we establish a couple
+    of helpful mappings variables. The reason this is helpful is that the
+    end result is simply an ordered set, the CSV file. But we still may
+    want to manipulate the values arbitrarily before writing that file.
+    
+    Also note that the current Auto Wx InfoEx documentation shows these
+    keys in a graphical table with the "index" beginning at 1, but here we
+    sanely index beginning at 0.
+    """
+    fmap = {}                           ; final_data     = [None] * 29
+    fmap['Location UUID'] = 0           ; final_data[0]  = location_uuid
+    fmap['obDate'] = 1                  ; final_data[1]  = None
+    fmap['obTime'] = 2                  ; final_data[2]  = None
+    fmap['timeZone'] = 3                ; final_data[3]  = 'Pacific'
+    fmap['tempMaxHour'] = 4             ; final_data[4]  = None
+    fmap['tempMaxHourUnit'] = 5         ; final_data[5]  = 'F'
+    fmap['tempMinHour'] = 6             ; final_data[6]  = None
+    fmap['tempMinHourUnit'] = 7         ; final_data[7]  = 'F'
+    fmap['tempPres'] = 8                ; final_data[8]  = None
+    fmap['tempPresUnit'] = 9            ; final_data[9]  = 'F'
+    fmap['precipitationGauge'] = 10     ; final_data[10] = None
+    fmap['precipitationGaugeUnit'] = 11 ; final_data[11] = 'in'
+    fmap['windSpeedNum'] = 12           ; final_data[12] = None
+    fmap['windSpeedUnit'] = 13          ; final_data[13] = 'mph'
+    fmap['windDirectionNum'] = 14       ; final_data[14] = None
+    fmap['hS'] = 15                     ; final_data[15] = None
+    fmap['hsUnit'] = 16                 ; final_data[16] = 'in'
+    fmap['baro'] = 17                   ; final_data[17] = None
+    fmap['baroUnit'] = 18               ; final_data[18] = 'inHg'
+    fmap['rH'] = 19                     ; final_data[19] = None
+    fmap['windGustSpeedNum'] = 20       ; final_data[20] = None
+    fmap['windGustSpeedNumUnit'] = 21   ; final_data[21] = 'mph'
+    fmap['windGustDirNum'] = 22         ; final_data[22] = None
+    fmap['dewPoint'] = 23               ; final_data[23] = None
+    fmap['dewPointUnit'] = 24           ; final_data[24] = 'F'
+    fmap['hn24Auto'] = 25               ; final_data[25] = None
+    fmap['hn24AutoUnit'] = 26           ; final_data[26] = 'in'
+    fmap['hstAuto'] = 27                ; final_data[27] = None
+    fmap['hstAutoUnit'] = 28            ; final_data[28] = 'in'
+
+    return (fmap, final_data)
+
+def setup_infoex_counterparts_mapping(provider):
+    """
+    Create a mapping of the NRCS/MesoWest fields that this program supports to
+    their InfoEx counterparts
+    """
+    iemap = {}
+
+    if provider == 'nrcs':
+        iemap['PREC'] = 'precipitationGauge'
+        iemap['TOBS'] = 'tempPres'
+        iemap['SNWD'] = 'hS'
+        iemap['PRES'] = 'baro'
+        iemap['RHUM'] = 'rH'
+        iemap['WSPD'] = 'windSpeedNum'
+        iemap['WDIR'] = 'windDirectionNum'
+        # unsupported by NRCS:
+        # windGustSpeedNum
+    elif provider == 'mesowest':
+        iemap['precip_accum'] = 'precipitationGauge'
+        iemap['air_temp'] = 'tempPres'
+        iemap['snow_depth'] = 'hS'
+        iemap['pressure'] = 'baro'
+        iemap['relative_humidity'] = 'rH'
+        iemap['wind_speed'] = 'windSpeedNum'
+        iemap['wind_direction'] = 'windDirectionNum'
+        iemap['wind_gust'] = 'windGustSpeedNum'
+
+    return iemap
+
+# provider-specific operations
+def get_nrcs_data(begin, end, data):
+    """get the data we're after from the NRCS WSDL"""
     transport = zeep.transports.Transport(cache=zeep.cache.SqliteCache())
     client = zeep.Client(wsdl=data['source'], transport=transport)
+    remote_data = {}
 
-    for elementCd in desired_data:
+    for elementCd in data['desired_data']:
         time_element = time.time()
 
         # get the last three hours of data for this elementCd
@@ -220,10 +359,10 @@ if data['provider'] == 'nrcs':
                 stationTriplets=[data['station_id']],
                 elementCd=elementCd,
                 ordinal=1,
-                beginDate=begin_date,
-                endDate=end_date)
+                beginDate=begin,
+                endDate=end)
 
-        log.info("Time to get elementCd '%s': %.3f sec" % (elementCd,
+        LOG.info("Time to get elementCd '%s': %.3f sec" % (elementCd,
             time.time() - time_element))
 
         values = tmp[0]['values']
@@ -235,15 +374,19 @@ if data['provider'] == 'nrcs':
         #       so perhaps this decision will be re-evaluated in the future
         if values:
             ordered = sorted(values, key=lambda t: t['dateTime'], reverse=True)
-            infoex['wx_data'][elementCd] = ordered[0]['value']
+            remote_data[elementCd] = ordered[0]['value']
         else:
-            infoex['wx_data'][elementCd] = None
+            remote_data[elementCd] = None
+
+    return remote_data
+
+def get_mesowest_data(begin, end, data):
+    """get the data we're after from the MesoWest/Synoptic API"""
+    remote_data = {}
 
-# MesoWest-specific code
-elif data['provider'] == 'mesowest':
     # massage begin/end date format
-    begin_date_str = begin_date.strftime('%Y%m%d%H%M')
-    end_date_str = end_date.strftime('%Y%m%d%H%M')
+    begin_date_str = begin.strftime('%Y%m%d%H%M')
+    end_date_str = end.strftime('%Y%m%d%H%M')
 
     # construct final, completed API URL
     api_req_url = data['source'] + '&start=' + begin_date_str + '&end=' + end_date_str
@@ -252,24 +395,24 @@ elif data['provider'] == 'mesowest':
     try:
         json = req.json()
     except ValueError:
-        log.error("Bad JSON in MesoWest response")
+        LOG.error("Bad JSON in MesoWest response")
         sys.exit(1)
 
     try:
         observations = json['STATION'][0]['OBSERVATIONS']
     except ValueError:
-        log.error("Bad JSON in MesoWest response")
+        LOG.error("Bad JSON in MesoWest response")
         sys.exit(1)
 
     pos = len(observations['date_time']) - 1
 
-    for elementCd in desired_data.split(','):
+    for elementCd in data['desired_data'].split(','):
         # sort and isolate the most recent, see note above in NRCS for how and
         # why this is done
         #
-        # NOTE: Unlike in the NRCS case, the MesoWest API respones contains all
+        # NOTE: Unlike in the NRCS case, the MesoWest API response contains all
         #       data (whereas with NRCS, we have to make a separate request for
-        #       each element we want. This is nice for network efficiency but
+        #       each element we want). This is nice for network efficiency but
         #       it means we have to handle this part differently for each.
         #
         # NOTE: Also unlike NRCS, MesoWest provides more granular data; NRCS
@@ -281,57 +424,36 @@ elif data['provider'] == 'mesowest':
         key_name = elementCd + '_set_1'
         if key_name in observations:
             if observations[key_name][pos]:
-                infoex['wx_data'][elementCd] = observations[key_name][pos]
+                remote_data[elementCd] = observations[key_name][pos]
             else:
-                infoex['wx_data'][elementCd] = None
+                remote_data[elementCd] = None
         else:
-            infoex['wx_data'][elementCd] = None
-
-log.info("Time to get all data : %.3f sec" % (time.time() -
-    time_all_elements))
-
-log.debug("infoex[wx_data]: %s", str(infoex['wx_data']))
-
-# Now we only need to add in what we want to change thanks to that
-# abomination of a variable declaration earlier
-final_data[fmap['Location UUID']] = infoex['location_uuid']
-final_data[fmap['obDate']] = end_date.strftime('%m/%d/%Y')
-final_data[fmap['obTime']] = end_date.strftime('%H:%M')
-
-for elementCd in infoex['wx_data']:
-    if elementCd not in iemap:
-        log.warning("BAD KEY wx_data['%s']" % (elementCd))
-        continue
-
-    # CONSIDER: Casting every value to Float() -- need to investigate if
-    #           any possible elementCds we may want are any other data
-    #           type than float.
-    #
-    #           Another possibility is to query the API  with
-    #           getStationElements and temporarily store the
-    #           storedUnitCd. But that's pretty network-intensive and
-    #           may not even be worth it if there's only e.g. one or two
-    #           exceptions to any otherwise uniformly Float value set.
-    final_data[fmap[iemap[elementCd]]] = infoex['wx_data'][elementCd]
-
-log.debug("final_data: %s" % (str(final_data)))
-
-with open(infoex['csv_filename'], 'w') as f:
-    # The requirement is that empty values are represented in the CSV
-    # file as "", csv.QUOTE_NONNUMERIC achieves that
-    log.debug("writing CSV file '%s'" % (infoex['csv_filename']))
-    writer = csv.writer(f, quoting=csv.QUOTE_NONNUMERIC)
-    writer.writerow(final_data)
-    f.close()
-
-if not options.dry_run:
-    # not a dry run
-    with open(infoex['csv_filename'], 'rb') as f:
-        log.debug("uploading FTP file '%s'" % (infoex['host']))
-        ftp = FTP(infoex['host'], infoex['uuid'], infoex['api_key'])
-        ftp.storlines('STOR ' + infoex['csv_filename'], f)
-        ftp.close()
+            remote_data[elementCd] = None
+
+    return remote_data
+
+# CSV operations
+def write_local_csv(path_to_file, data):
+    """Write the specified CSV file to disk"""
+    with open(path_to_file, 'w') as f:
+        # The requirement is that empty values are represented in the CSV
+        # file as "", csv.QUOTE_NONNUMERIC achieves that
+        LOG.debug("writing CSV file '%s'" % (path_to_file))
+        writer = csv.writer(f, quoting=csv.QUOTE_NONNUMERIC)
+        writer.writerow(data)
         f.close()
-    os.remove(infoex['csv_filename'])
+    return True
+
+def upload_csv(path_to_file, infoex_data):
+    """Upload the specified CSV file to InfoEx FTP and remove the file"""
+    with open(path_to_file, 'rb') as file_object:
+        LOG.debug("uploading FTP file '%s'" % (infoex_data['host']))
+        ftp = FTP(infoex_data['host'], infoex_data['uuid'],
+                  infoex_data['api_key'])
+        ftp.storlines('STOR ' + path_to_file, file_object)
+        ftp.close()
+        file_object.close()
+    os.remove(path_to_file)
 
-log.debug('DONE')
+if __name__ == "__main__":
+    sys.exit(main())