Script that downloads file from server and pipes it to external program

fetch_file_fserver.py

# https://stackoverflow.com/questions/24562590/login-to-webpage-from-script-using-requests-and-django 

import requests
import re
import datetime
import time
import subprocess

base_url = 'http://localhost:8000'
url_login= base_url +'/accounts/login/'
orderlist_url = base_url + '/producers/orderlist'
check_order_url = base_url + '/producers/checkorder'
order_url = base_url + '/producers/order/'
order_file_url = order_url + 'file/'
order_done_url = order_url + 'done/'

TIMER_DELAY = 120
DEFAULT_FILENAME = 'model.gcode'

regex = r'<li>.*?<\/li>'
PRINTER_ID = 14
prev_date_check = None


user = 'username'
password = 'password'

def on_unix(filename):
    """
    Function that creates unix command text for a given filename
    and saves this into file named command which is later executed 
    by subprocess.Popen 
    """
    _command = "(echo connect;echo load {};echo print;) | pronsole".format(filename)
    with open('command', 'wb') as f:
        f.write(_command)

def get_priority_token(tokens,PRINTER_ID):
    """
    Function that parses "14-dca6e2d8f368b9c258c5" where 
    '14' indicates to printer id 'dca6e2d8f368b9c258c5' is 
    file token this url will redirect to file url returns None
    if tokens doesnt have given printer id
    """
    for token in tokens:
        _token = token[4:-5].split('-')
        _printer_id = int(_token[0])
        if _printer_id == PRINTER_ID:
            return _token[1]
    return None

if __name__ == '__main__':
    """
    Script that fetches file from printer site and saves it with 
    DEFAULT_FILENAME name locally it firstly logins to website and 
    stores csrftoken after that will check 'check_order_url' and 
    read response header 
    'Last-Update' is date shows when last order is booked
    current user has will cache that number to 'prev_date_check'
    will request for header['Last-Update'] if it passes then send request
    to the part list
    then loades 'orderlist_url' where orders listed with tokens 
    parses them and 'get_priority_token' returns first token match with printer id
    downloades that file into local storage
    **for gcode using tokens might be good idea
    """
    client = requests.session()
    client.cookies.clear()
    r1 = client.get(url_login)
    csrftoken = client.cookies['csrftoken']
    login_data = {'username':user,'password':password, 'csrfmiddlewaretoken':csrftoken}
    client_logged = client.post(url_login,data=login_data,allow_redirects=True)

    while True:
        check = client.get(check_order_url).headers['Last-Update']
        last_update = datetime.datetime.strptime(check, '%a, %d %b %Y %H:%M:%S GMT')
        if prev_date_check is None or last_update > prev_date_check:
            payload = client.get(orderlist_url)
            tokens = re.findall(regex,payload.text)
            file_token = get_priority_token(tokens,PRINTER_ID)
            if file_token:
                r = client.get(order_file_url + file_token, allow_redirects=True)
                open(DEFAULT_FILENAME,'wb').write(r.content)
            on_unix(DEFAULT_FILENAME)
            p = subprocess.Popen(["/bin/bash","command"],stdin=subprocess.PIPE,stdout=subprocess.PIPE)
            stdout = p.communicate() #remove stdout cz it may couse unnecessary memory usage
        else:
            time.sleep(TIMER_DELAY)
        prev_date_check = check