各种请求方式（get请求）

wd = input("输入关键字")

#get请求参数

data = {

   'wd':wd,
   'ie':'utf8'

}

url = 'http://www.baidu.com/s?'

#处理参数

data = urllib.parse.urlencode(data)

#拼接路径

url += data

#构建请求对象

headers = {

      'User-Agent':'Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.132 Safari/537.36 QIHU 360SE'
   }

request = urllib.request.Request(url=url,headers=headers)

#获取响应对象

response = urllib.request.urlopen(request)

#保存文件

with open('文件路径','wb') as fp:

fp.write(response.read())