pi@raspberrypi:~ $ cat Temp.py
import Adafruit_DHT
import time

DHT_SENSOR = Adafruit_DHT.DHT11
DHT_PIN = 4
humidity, temperature = Adafruit_DHT.read(DHT_SENSOR, DHT_PIN)
if humidity is not None and temperature is not None:
    print("{0:0.1f},{1:0.1f}".format(temperature,humidity))
else:
    print("-1,-1");