python - 在 python 中使用 beautifulsoup 有问题

Question

我是 python 的新手，在使用下面的代码时遇到了问题。我试图在网站上获取温度或日期，但似乎无法获得输出。我尝试了很多变体，但似乎仍然无法正确处理..

感谢您的帮助!

#Code below: 
import requests,bs4
r = requests.get('http://www.hko.gov.hk/contente.htm')
print r.raise_for_status()
hkweather = bs4.BeautifulSoup(r.text)
print hkweather.select('div left_content fnd_day fnd_date')

Answer 1

你的 css 选择器不正确，你应该在标签和 css 类之间使用 .，你想要的标签在 div 中，在 div 中有 fnd_day 类id fnd_content

divs = soup.select("#fnd_content div.fnd_day")

但是仍然无法获取数据，因为它是通过 ajax 请求动态生成的，您可以使用以下代码获取 json 格式的所有数据:

u = "http://www.hko.gov.hk/wxinfo/json/one_json.xml?_=1468955579991"

data = requests.get(u).json()

from pprint import pprint as pp
pp(data)

这会返回几乎所有的动态内容，包括日期和时间等。

如果您访问 key F9D，您可以看到所有温度和日期的一般天气描述:

from pprint import pprint as pp

pp(data['F9D'])

输出:

{'BulletinDate': '20160720',
 'BulletinTime': '0315',
 'GeneralSituation': 'A southwesterly airstream will bring showers to the '
                     'coast of Guangdong today. Under the dominance of an '
                     'upper-air anticyclone, it will be generally fine and '
                     'very hot over southern China in the latter part of this '
                     'week and early next week.',
 'NPTemp': '25',
 'WeatherForecast': [{'ForecastDate': '20160720',
                      'ForecastIcon': 'pic53.png',
                      'ForecastMaxrh': '95',
                      'ForecastMaxtemp': '32',
                      'ForecastMinrh': '70',
                      'ForecastMintemp': '26',
                      'ForecastWeather': 'Sunny periods and a few showers. '
                                         'Isolated squally thunderstorms at '
                                         'first.',
                      'ForecastWind': 'South to southwest force 4.',
                      'IconDesc': 'Sunny Periods with A Few Showers',
                      'WeekDay': '3'},
                     {'ForecastDate': '20160721',
                      'ForecastIcon': 'pic90.png',
                      'ForecastMaxrh': '90',
                      'ForecastMaxtemp': '33',
                      'ForecastMinrh': '65',
                      'ForecastMintemp': '28',
                      'ForecastWeather': 'Mainly fine and very hot apart from '
                                         'isolated showers in the morning.',
                      'ForecastWind': 'South to southwest force 3 to 4.',
                      'IconDesc': 'Hot',
                      'WeekDay': '4'},
                     {'ForecastDate': '20160722',
                      'ForecastIcon': 'pic90.png',
                      'ForecastMaxrh': '90',
                      'ForecastMaxtemp': '33',
                      'ForecastMinrh': '65',
                      'ForecastMintemp': '28',
                      'ForecastWeather': 'Mainly fine and very hot apart from '
                                         'isolated showers in the morning.',
                      'ForecastWind': 'Southwest force 3.',
                      'IconDesc': 'Hot',
                      'WeekDay': '5'},
                     {'ForecastDate': '20160723',
                      'ForecastIcon': 'pic90.png',
                      'ForecastMaxrh': '90',
                      'ForecastMaxtemp': '34',
                      'ForecastMinrh': '65',
                      'ForecastMintemp': '29',
                      'ForecastWeather': 'Fine and very hot.',
                      'ForecastWind': 'Southwest force 3.',
                      'IconDesc': 'Hot',
                      'WeekDay': '6'},
                     {'ForecastDate': '20160724',
                      'ForecastIcon': 'pic90.png',
                      'ForecastMaxrh': '90',
                      'ForecastMaxtemp': '34',
                      'ForecastMinrh': '65',
                      'ForecastMintemp': '29',
                      'ForecastWeather': 'Fine and very hot.',
                      'ForecastWind': 'Southwest force 3.',
                      'IconDesc': 'Hot',
                      'WeekDay': '0'},
                     {'ForecastDate': '20160725',
                      'ForecastIcon': 'pic90.png',
                      'ForecastMaxrh': '90',
                      'ForecastMaxtemp': '33',
                      'ForecastMinrh': '65',
                      'ForecastMintemp': '29',
                      'ForecastWeather': 'Mainly fine and very hot apart from '
                                         'isolated showers in the morning.',
                      'ForecastWind': 'South to southwest force 3.',
                      'IconDesc': 'Hot',
                      'WeekDay': '1'},
                     {'ForecastDate': '20160726',
                      'ForecastIcon': 'pic90.png',
                      'ForecastMaxrh': '90',
                      'ForecastMaxtemp': '33',
                      'ForecastMinrh': '65',
                      'ForecastMintemp': '29',
                      'ForecastWeather': 'Mainly fine and very hot apart from '
                                         'isolated showers in the morning.',
                      'ForecastWind': 'South to southwest force 3.',
                      'IconDesc': 'Hot',
                      'WeekDay': '2'},
                     {'ForecastDate': '20160727',
                      'ForecastIcon': 'pic90.png',
                      'ForecastMaxrh': '90',
                      'ForecastMaxtemp': '33',
                      'ForecastMinrh': '65',
                      'ForecastMintemp': '28',
                      'ForecastWeather': 'Mainly fine and very hot apart from '
                                         'isolated showers in the morning.',
                      'ForecastWind': 'Southwest force 3 to 4.',
                      'IconDesc': 'Hot',
                      'WeekDay': '3'},
                     {'ForecastDate': '20160728',
                      'ForecastIcon': 'pic90.png',
                      'ForecastMaxrh': '90',
                      'ForecastMaxtemp': '33',
                      'ForecastMinrh': '65',
                      'ForecastMintemp': '28',
                      'ForecastWeather': 'Mainly fine and very hot apart from '
                                         'isolated showers in the morning.',
                      'ForecastWind': 'Southwest force 3 to 4.',
                      'IconDesc': 'Hot',
                      'WeekDay': '4'}]}

唯一的查询字符串参数是 epoch timestamp您可以使用时间库生成:

from time import time
u = "http://www.hko.gov.hk/wxinfo/json/one_json.xml?_={}".format(int(time()))

data = requests.get(u).json()

不传递时间戳也会返回相同的数据，所以我将让您调查其重要性。