Upload data from a DexCom G4 CGM into nightscout using dexcom_reader and pymongo

dexcom_uploader.py

#!/usr/bin/env python
# replace MONGO_URI with your own nightscout mongo URI
MONGO_URI = 'mongodb://nightscout.example.com:1234/'
import dexcom_reader.readdata
import time

from serial.serialutil import SerialException
from datetime import datetime, date
from pymongo import MongoClient
mongo_client = MongoClient(MONGO_URI)
db = mongo_client.nightscout

def unix_time(dt):
    epoch = datetime.fromtimestamp(0) #NOT utc (ugh)
    delta = dt - epoch
    return delta.total_seconds()

def unix_time_millis(dt):
    return long(unix_time(dt) * 1000) - (3600000 if time.localtime().tm_isdst else 0) 
    
name_map = {None: 'NONE', 'DOUBLE_UP':'DoubleUp', 'SINGLE_UP':'SingleUp', 
                 '45_UP':'FortyFiveUp', 'FLAT':'Flat', '45_DOWN':'FortyFiveDown', 
                 'SINGLE_DOWN':'SingleDown', 'DOUBLE_DOWN':'DoubleDown', 
                 'NOT_COMPUTABLE':'NOT COMPUTABLE', 'OUT_OF_RANGE':'OUT OF RANGE'}
old_last_time = datetime.fromtimestamp(0)
old_last = 0
start_time = datetime.now()
while True:
    try:
            dd = dexcom_reader.readdata.Dexcom.FindDevice()
            dr = dexcom_reader.readdata.Dexcom(dd)
            records = dr.ReadRecords('EGV_DATA')
            last = 0
            for record in records:
                if not record.is_special:
                    old_last = last
                    for_mongo = {'device':'dexcom', 'date':unix_time_millis(record.display_time), 'dateString':str(record.display_time), 'type':'sgv', 'sgv':record.glucose, 'direction':name_map[record.trend_arrow]}
                    last_time, last = record.display_time, record.glucose
                    if old_last_time < last_time:
                        if (last_time > start_time):
                             db.entries.insert(for_mongo)                            
                        print last_time, last, '\033]0;%s %+d\007'%(last,last - old_last)                     
            if old_last_time != last_time:
                old_last_time = last_time
                old_last = last
    except Exception as e:
        print (e)
        time.sleep(30)