Modified from the source at https://learn.adafruit.com/dht-humidity-sensing-on-raspberry-pi-with-gdocs-logging/python-setup

DHT22.py

import time
import board
import adafruit_dht
from  paho.mqtt import publish

# Initial the dht device, with data pin connected to:
dhtDevice = adafruit_dht.DHT22(board.D21)


while True:
    try:
        # Print the values to the serial port
        temperature_c = dhtDevice.temperature
        humidity = dhtDevice.humidity
        print(
            "Temp:{:.1f} C    Humidity: {}% ".format(
               temperature_c, humidity
            )
        )

        publish.single("dht22/humidity", humidity)
        publish.single("dht22/temperature", temperature_c)

    except (RuntimeError, OverflowError) as error:
        # Errors happen fairly often, DHT's are hard to read, just keep going
        print(error.args[0])

    time.sleep(2.0)