Use python to crawl Baidu images,The script is written in python2.
一，怎么使用此脚本(How to use this script)
下载此脚本之后，在linux环境下，直接使用“python Spider_baidu_picture.py或者./Spider_baidu_picture.py”即可，然后输入您所需要爬取的图片的关键字（中英文都可以），执行之后的结果将会根据您所输入的关键字在当前目录下面自动生成一个文件夹，并将所爬取的图片存入此文件夹中；
After downloading this script, in the Linux environment, use "python Spider_baidu_picture.py or ./Spider_baidu_picture.py" directly, then enter the keyword of the image you need to crawl (both in English and Chinese), and execute the result. A folder will be automatically generated under the current directory based on the keyword you entered, and the captured image will be saved in this folder;
如果出现Spider_baidu_picture.py无法执行的情况，请赋予Spider_baidu_picture.py可执行的权限（chmod 777 Spider_baidu_picture.py）
If Spider_baidu_picture.py cannot be executed, give Spider_baidu_picture.py executable permissions（chmod 777 Spider_baidu_picture.py）.
如下图所示(As shown below)：
二，代码简介(Code introduction)
1,导入相关库(Import related libraries)：
————re：正则(Regular)；
————requests：是python实现的简易的HTTP库(Is a simple HTTP library implemented by Python)
————os:用于处理文件和目录的库(Library for working with files and directories)
————datetime：时间模块(Time module)
2,curl_path：即用os库来获取当前文件的位置(Use the os library to get the location of the current file.)
3,getpic函数：(getpic function)
(1)picture_url：首先通过正则获取此html页面所有的图片url(First, get all the image urls of this html page by regularity);
(2)golbal_path:根据keyword生成一个名为keyword的文件夹(Generate a folder named keyword based on the keyword);
(3)for循环中的内容：(Content in the for loop)
循环遍历picture_url中的所有图片的url，然后通过requests.get来获取图片，并且通过try...except来处理两个常见的异常，然后将所有爬取的图片存入到以keyword命名的文件夹中，并且用当前时间（datetime.datetime.now())来命名所获得的图片，以此来防止图片重名的问题；
Loop through the urls of all the images in picture_url, then get the images through requests.get, and handle two common exceptions by try...except, then save all the crawled images to the folder named after the keyword Medium, and use the current time (datetime.datetime.now ()) to name the obtained image, in order to prevent the problem of the name of the picture;
4，if name == 'main':
（1）input_word：获取输入的关键字(Get the entered keyword)；
（2）urls:通过观察百度图片中的url不同页码之间的区别(By observing the difference between the different page numbers of the url in Baidu pictures:):
第一页：http://image.baidu.com/search/flip?tn=baiduimage&ie=utf-8&word=cat&pn=0
第二页：http://image.baidu.com/search/flip?tn=baiduimage&ie=utf-8&word=cat&pn=20
第三页：http://image.baidu.com/search/flip?tn=baiduimage&ie=utf-8&word=cat&pn=40
总结：即pn=0时对应第1页，pn=20时对应第二页，以此类推，故：
通过此 urls = ["http://image.baidu.com/search/flip?tn=baiduimage&ie=utf-8&word="+input_word+"&pn={}".format(str(i)) for i in range(0,81,20)]来获取其前5页的所有图片。
（3）for循环：依次遍历每页的url，并且调用getpic函数下载图片（Iterate through the url of each page in turn, and call the getpic function to download the image.）。