Python script to run via cronjob, read sensor data, and push data into RethinkDB.

pusherRethinkDB.py

import socket
import rethinkdb as r
import time
import Adafruit_DHT
import datetime
import logging
import sys

logging.basicConfig(
    level=logging.INFO,
    format='%(asctime)s %(name)-12s %(levelname)-8s %(message)s',
    datefmt='%m-%d %H:%M'
    )

sensor = Adafruit_DHT.AM2302

pin = 22

HOSTNAME = socket.gethostname()

DB_HOST = "0.0.0.0"
DB_PORT = 28015
DB_NAME = "telemetry_pi"

logging.info("Attempting db connection...")
conn = r.connect(DB_HOST, DB_PORT, DB_NAME)
logging.info("Successful DB connection")

logging.info("Checking if db exists")
if DB_NAME not in list(r.db_list().run(conn)):
    logging.info("db does not exist, creating...")
    r.db_create(DB_NAME).run(conn)
logging.info("db exists")

logging.info("Checking to see if table exists")
if 'observations' not in list(r.table_list().run(conn)):
    logging.info("table does not exist, creating...")
    r.table_create("observations").run(conn)
logging.info("table exists")
conn.close()

logging.info("Attempting to read from sensor")
humidity, temperature = Adafruit_DHT.read_retry(sensor, pin)
if humidity is not None and temperature is not None:
    conn = r.connect(DB_HOST, DB_PORT, DB_NAME)
    timezone = time.strftime("%z")
    reql_tz = r.make_timezone(timezone[:3] + ":" + timezone[3:]) #You need to modify this if you are not in Pacific Standard Time!

    r.table("observations").insert(dict(
            hostname=HOSTNAME,
            temp=temperature,
            humidity=humidity,
            datetime=datetime.datetime.now(reql_tz)
        )).run(conn, durability='soft') #Soft durability since losing one observation wouldn't be the end of the world. 
    conn.close()

    logging.info("Successful sensor read (Temp: {:+.2f}, Humid: {:+.2f}) and insert into DB.".format(
            temperature, humidity))