Send sweet nothings with Lambda and Twilio

lambda.py

import base64
import json
import os
import urllib
import random
from urllib import request, parse


TWILIO_SMS_URL = "https://api.twilio.com/2010-04-01/Accounts/{}/Messages.json"
TWILIO_ACCOUNT_SID = os.environ.get("TWILIO_ACCOUNT_SID")
TWILIO_AUTH_TOKEN = os.environ.get("TWILIO_AUTH_TOKEN")
MY_NUMBER = os.environ.get("MY_NUMBER")
PARTNERS_NUMBER = os.environ.get("PARTNERS_NUMBER")


def lambda_handler(event, context):
  
    # this determines the average frequency of that that the message is sent .075 means that roughly 1/13 times it will send
    send_this_time = random.random() < 0.075

    to_number = PARTNERS_NUMBER
    from_number = MY_NUMBER

    # add your own sweet nothings to this array
    message_list = [
      "I love you!",
      "I am so lucky to have you in my life!"
    ]

    # put your own name, sign-offs, pet names in this list
    sign_off_list = [
      "Randy",
      "Fiancee"
    ]

    body = random.choice(message_list) + " -" + random.choice(sign_off_list)

    if not send_this_time:
        return "RNG says no"
    elif not TWILIO_ACCOUNT_SID:
        return "Unable to access Twilio Account SID."
    elif not TWILIO_AUTH_TOKEN:
        return "Unable to access Twilio Auth Token."
    elif not to_number:
        return "The function needs a 'To' number in the format +12023351493"
    elif not from_number:
        return "The function needs a 'From' number in the format +19732644156"
    elif not body:
        return "The function needs a 'Body' message to send."

    # insert Twilio Account SID into the REST API URL
    populated_url = TWILIO_SMS_URL.format(TWILIO_ACCOUNT_SID)
    post_params = {"To": to_number, "From": from_number, "Body": body}

    # encode the parameters for Python's urllib
    data = parse.urlencode(post_params).encode()
    req = request.Request(populated_url)

    # add authentication header to request based on Account SID + Auth Token
    authentication = "{}:{}".format(TWILIO_ACCOUNT_SID, TWILIO_AUTH_TOKEN)
    base64string = base64.b64encode(authentication.encode('utf-8'))
    req.add_header("Authorization", "Basic %s" % base64string.decode('ascii'))

    try:
        # perform HTTP POST request
        with request.urlopen(req, data) as f:
            print("Twilio returned {}".format(str(f.read().decode('utf-8'))))
    except Exception as e:
        # something went wrong!
        return e

    return "SMS sent successfully!"