python之requests示例

1)

import  requests

def download(url, num_tries=2, user_agent='wswp', proxies=None):
    '''
    下载指定url并返回网页内容
    :param url:  请求URL
    :param num_tries: 重试次数
    :param user_agent: 用户代理
    :param proxies: 代理(字典): 键(http/https)
    :return:
    '''
    headers = {'User-Agent':user_agent}
    try:
        res = requests.get(url, headers=headers, proxies=proxies)
        res.encoding = 'utf-8'
        html = res.text
        if res.status_code >= 400:
            html = None
            if num_tries and 500 <= res.status_code < 600: # 发生5xx错误
                return download(url,num_tries-1)
    except requests.exceptions.RequestException as e:
        print('Downlaod error:',e)
        html = None
    return html

print(download('http://www.baidu.com'))

 

2)下载图片

import requests
from urllib.request import urlretrieve

def image_download():
    '''
    下载百度图片
    '''
    image_url = 'https://img0.baidu.com/it/u=160780349,781446406&fm=253&fmt=auto&app=120&f=JPEG?w=1024&h=576'
    # 方法1
    # content = requests.get(image_url).content  # 获取二进制图片
    # print(content)
    # with open('mv.jpeg', 'wb') as fp:
    #     fp.write(content)

    # 方法2
    urlretrieve(image_url, 'mv2.jpeg')