从数据库中读取图片链接，用协程gevent将图片下载到指定目录保存

1、链接数据库

from pymysql import *

# 创建connection链接， 链接数据库
conn = connect(host='192.168.79.136', port=3306, database='yi_heng', user='root', password='abc123@2018', charset='utf8')
# 获取cursor游标对象
cursor = conn.cursor()
count = cursor.execute("select * from BOOHEE_Foods_data")
# print(count)
result = cursor.fetchall()
# print(result)

url_list = []

for row in result:
    # print(row)
    data = row  # 对应数据库中的image_url
    url_list.append(data)

print(url_list)

2、运用python的协程gevent进行下载

import client_mysql
import gevent
import urllib.request
from gevent import monkey
import time

# 有耗时操作时使用
monkey.patch_all()

def download(image_name, url):
    # 文件位置
    file_name = '/home/python/Desktop/yiheng/医疗养生/food/New_Foods_image'
    # 打开制定的url
    respond = urllib.request.urlopen(url)
    # 读文件
    data = respond.read()
    # 写入文件
    with open(file_name + '/' + image_name, "wb") as f:
        f.write(data)

def main():
    """控制程序的整体运行"""
    
    for url in client_mysql.url_list:

        gevent.joinall([
            gevent.spawn(download, str(url[2])+'.jpg', url[3])
        ])

        time.sleep(1)

if __name__ == '__main__':
    main()