Fill a web contact form with Random Name, email, subject and message with Python

I need to create a python code that can fill out a web contact form with random data. The code should take emails from a JSON or text file, take names from a JSON or text file, messages from a list of messaged stored in messages.json or txt and same for "subject Field) and then visit a URL, fill these fields and then send the contact form,

we will set a limit to 20-30 contact form fills per time (day) and then it stops running, it will be ideal if it can send one form for every random amount of time between 30 Minutes to 2 Hours

So far what I have is not even close. I am relatively new to python

My Code so far:

import requests
import os
import random
import string
import json

chars = string.ascii_letters + string.digits + '!@#$%^&*()'
random.seed = (os.urandom(1024))

url = 'https://www.webiste.com/contact.php'

names = json.loads(open('names.json').read())

for name in names:
    name_extra = ''.join(random.choice(string.digits))

for email in emails:
    email_extra = email

    requests.post(url, allow_redirects=False, data={
        sent_name = name_extra
        sent_email = email_extra
        subject = ''
        message = ''
    })

    print 'Form Filled and Submited'