This script periodically polls the AM2302 (DHT11) sensor for Temperature and humidity data, logs it locally to a csv file and also sends the data to ThingSpeak. Script is working on Python3.

getTempHumData.py

"""
Based on Humidity and Temperature data logging script by Anurag Kotha

Updated 10.03.2022 - now script is working with Python3 on raspberry pi
"""

# Import all the libraries we need to run
import sys
import os
import time
import Adafruit_DHT
import urllib.request, urllib.error, urllib.parse



pwd = "/home/pi/TempHum/"
DEBUG = 0
# Setup the pins we are connected to
DHTpin = 4

#Setup our API and delay
myAPI = "YOUR_API_KEY" # *** SET YOUR API KEY HERE. WONT WORK OTHERWISE
myDelay = 180 #how many seconds between posting data

# File name for data logging
fname = pwd + 'TemHumLog_'+time.strftime("%d%m%Y", time.gmtime()) + '.csv'
# File name for error recovery
fErrRec = pwd + 'TempHumErrorStatus.log'

def getSensorData():
    RHW, TW = Adafruit_DHT.read_retry(Adafruit_DHT.AM2302, DHTpin) # Change AM2302 to DHT11 if you have DHT11 sensor
    #Convert from Celius to Farenheit
    TWF = 9/5*TW+32
    # return dict
    return (str(RHW), str(TW),str(TWF))

# main() function
def main():
        print('starting... ')

        baseURL = 'https://api.thingspeak.com/update?api_key=%s' % myAPI
        print (baseURL)

        while True:
                try:
                        mTime = time.strftime("%d/%m/%Y %H:%M:%S",time.gmtime())
                        RHW, TW, TWF = getSensorData()

                        # Log data to file
                        mData = "%s,%s,%s,%s\n" %(mTime,TW,TWF,RHW)
                        logfile = open(fname,'a')
                        logfile.write(mData)
                        logfile.close()
                        print ("Time  " + mTime,"  Temperature C  " + TW + "  Temperature F  " + TWF + " Humidity   " + RHW)

                        # Log error status to file
                        logfile = open(fErrRec,'a')
                        logfile.write("1\n")
                        logfile.close()
                        time.sleep(int(myDelay))

                except:
                        # Log error status to file
                        logfile = open(fErrRec,'a')
                        logfile.write("0\n")
                        logfile.close()
                        print('Exception caught')
                        # break                   Dont want to exit everytime we loose network connection.

                try:
                        # Send data to ThingSpeak takes some time to open the connection
                        f = urllib.request.urlopen(baseURL + "&field1=%s&field2=%s&field3=%s" % (TW, TWF, RHW)+ "&field4=%s" % ('1'))
                except:
                        # Log error status to file
                        logfile = open(fErrRec,'a')
                        logfile.write("0")
                        logfile.close()
                        print ('Failed to connect to the server.')

# call main
if __name__ == '__main__':
    main()