多线程下载图片

"""import os, multiprocessing
import urllib3, certifi
import pandas as pd
import numpy as np

def DownloadImage(key_url):
    try:
        (key, url, out_dir) = key_url.values[0]
        filename = os.path.join(out_dir, '%s.jpg' % key)
        image_data = urllib3.PoolManager(cert_reqs='CERT_REQUIRED', ca_certs=certifi.where()).request('GET', url).data
        f = open(filename,"wb")
        f.write(image_data)
        f.close
    except:
        print('Warning: Could not download image', key_url.values[0])
    return

def Run(key_url_list):
    if not os.path.exists(key_url_list['out_dir'][0]):
        os.mkdir(key_url_list['out_dir'][0])
    p = multiprocessing.Pool(multiprocessing.cpu_count())
    p.map(DownloadImage, np.array_split(key_url_list, len(key_url_list)))
    p.close(); p.join()

if __name__ == '__main__':
    col = ['id','url','out_dir']

    train = pd.read_csv('../input/train.csv')[:2]
    test = pd.read_csv('../input/test.csv')[:2]

    train['out_dir'] = 'train_out/'
    test['out_dir'] = 'test_out/'

    Run(train[col])
    Run(test[col])
"""
print("Happy Kaggling :)")