_’’’
    爬取天气案例
    需求:爬取近7天的天气(日期,天气,温度,风力)
    url: http://www.weather.com.cn/weather/101250101.shtml(湖南长沙近7天的天气预报)
    (查看网页源码:查找:今天,在源码上找到了,所以上面的url就是今天的目标url)
    步骤:
    1)获取整个网页源码
    2)获取url数据
    3)在ul数据里面找li数据
    4)在li数据提取 日期,天气,温度,风力
    5)保存到CSV文件里
    ‘’’

    _import requests
    import re
    import csv

    url = ‘http://www.weather.com.cn/weather/101250101.shtml‘
    headers = {
    ‘user-agent’: ‘Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/99.0.4844.51 Safari/537.36’
    }
    #发请求,获取响应
    res = requests.get(url)
    res.encoding = ‘utf-8’
    html = res.text
    result = re.match(r’.(

      .?
    ).*’, html, re.S)
    ul = result.group(1)

    lis = re.findall(r’.?‘, ul, re.S)
    pattern = re.compile(r’<li.    ?>.?

    (.?)

    .?<p.?>(.?)

    .    ?(.?).?(.?).‘, re.S)
    data = []
    for i in lis:
    r = pattern.match(i)
    # print(r.group(1), r.group(2), r.group(3), r.group(4))
    data.append((r.group(1), r.group(2), r.group(3), r.group(4)))

    with open(‘weather.csv’, ‘w’, encoding=’utf-8’, newline=’’) as f:
    # 创建写入对象
    writer = csv.writer(f)
    # 写入表头(也要写成列表的形式)
    writer.writerow([“日期”, “天气”, “温度”, “风力”])
    writer.writerows(data)

    注意:csv的写入,数据形式只能有两种: 1)列表 2)字典