python large file download

filedownload.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-
from pathlib import Path
import requests
from random import randint

base_timeout = 10
headers = {'User-Agent': '-UserAgentStrings-'}

# pip install fake-useragent
# from fake_useragent import UserAgent
# ua = UserAgent()
# ua.chrome
# headers = {'User-Agent': ua.chrome}

from hashlib import md5

def md5_encrypt(data):
    hash_distinct = md5(data.encode('utf-8')).hexdigest()
    return hash_distinct

def read_and_write(data):
    with open('file.csv', 'r') as read:
        lines = read.readlines()
    read.close
    with open('file.csv', 'a') as out:
        out.write('%s' % (data))
    out.close
    with open('hash.txt', 'w') as out:
        out.write('%s' % (data)
    out.close()

def download_files(url, file_dir, file_name):
    file_request = requests.get(url, stream=True, headers=headers, timeout=basic_timeout*2)
    if not os.path.isdir(file_dir):
        os.makedirs(file_dir)
    file_path = '%s%s' % (file_dir, file_name)
    with open(file_path, 'wb') as out_file:
        for chunk in file_request.iter_content(chunk_size=1024):
            if chunk:
                out_file.write(chunk)
        del file_request

import threading
class downloadWorker(threading.Thread):
    def __init__(self, images):
        threading.Thread.__init__(self)
        self.name = "image_worker"
        self.images = images
    def run(self):
        print ("start：" + self.name)
        # func(args)
        print ("exit：" + self.name)