from bs4 import BeautifulSoup
import requests
import os
import shutil

headers = {
    "Accept": "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8",
    "Accept-Language": "zh-CN,zh;q=0.8",
    "Connection": "close",
    "Cookie": "_gauges_unique_hour=1; _gauges_unique_day=1; _gauges_unique_month=1; _gauges_unique_year=1; _gauges_unique=1",
    "Referer": "http://www.infoq.com",
    "Upgrade-Insecure-Requests": "1",
    "User-Agent": "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/57.0.2987.98 Safari/537.36 LBBROWSER"
}

url = 'http://www.infoq.com/presentations'


# 下载图片
# Requests 库封装复杂的接口，提供更人性化的 HTTP 客户端，但不直接提供下载文件的函数。
# 需要通过为请求设置特殊参数 stream 来实现。当 stream 设为 True 时，
# 上述请求只下载HTTP响应头，并保持连接处于打开状态，
# 直到访问 Response.content 属性时才开始下载响应主体内容


def download_jpg(image_url, image_localpath):
    response = requests.get(image_url, stream=True)
    if response.status_code == 200:
        with open(image_localpath, 'wb') as f:
            response.raw.deconde_content = True
            shutil.copyfileobj(response.raw, f)


# 取得演讲图片
def craw3(url):
    response = requests.get(url, headers=headers)
    soup = BeautifulSoup(response.text, 'lxml')
    for pic_href in soup.find_all('div', class_='items__content'):
        for pic in pic_href.find_all('img'):
            imgurl = pic.get('src')
            dir = os.path.abspath('.')
            filename = os.path.basename(imgurl)
            imgpath = os.path.join(dir, filename)
            print('开始下载 %s' % imgurl)
            download_jpg(imgurl, imgpath)


# craw3(url)

# 翻页
j = 0
for i in range(12, 37, 12):
    url = 'http://www.infoq.com/presentations' + str(i)
    j += 1
    print('第 %d 页' % j)
    craw3(url)