所爬取的网页链接，
本例为：​​​http://college.koolearn.com/upload/school/kaoyan/10359.jpg​​​ 所爬取的网页链接，结尾必须是.jpg才可以得到一个照片！
源代码：

import requests
import os
url = "http://college.koolearn.com/upload/school/kaoyan/10359.jpg"
root = "D://爬取单个照片！//"
path = root + url.split('/')[-1]
try:
    if not os.path.exists(root):
        os.mkdir(root)
    if not os.path.exists(path):
        r = requests.get(url)
        with open(path,'wb') as f:
            f.write(r.content)
            f.close()
            print("文件保存成功！")
    else:
        print("文件已经存在")
except:
    print("获取失败！")

成功！

OK！