import urllib.request

def load_baidu():

    url= "https://www.baidu.com"

    header = {

        #浏览器的版本

        "User-Agent":"Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/69.0.3497.100 Safari/537.36",

        # "haha":"hehe"

    }

    #创建请求对象

    request = urllib.request.Request(url)

    #动态的去添加head的信息

    request.add_header("User-Agent","Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/69.0.3497.100 Safari/537.36")

    #请求网络数据(不在此处增加请求头信息因为此方法系统没有提供参数)

    response = urllib.request.urlopen(request)

    print(response)

    data = response.read().decode("utf-8")

    #获取到完整的url

    final_url = request.get_full_url()

    print(final_url)

    #响应头

    # print(response.headers)

    #获取请求头的信息(所有的头的信息)

    # request_headers = request.headers

    # print(request_headers)

    #(2)第二种方式打印headers的信息

    #注意点:首字母需要大写,其他字母都小写

    request_headers = request.get_header("User-agent")

    # print(request_headers)

    with open("02header.html","w")as f:

        f.write(data)

load_baidu()