用python+selenium获取北上广深成五地PM2.5数据信息并按空气质量排序

#coding=utf-8
from selenium import webdriver
from time import sleep

class PM:

def __init__(self):
self.dr = webdriver.Chrome()
self.pm25_info = self.get_pm25_info()

def get_pm25_info(self):
city_list = ['beijing','shenzhen','shanghai','guangzhou','chengdu']
pm_info_list = []
i = 0
while i < len(city_list):
self.dr.get('http://www.pm25.com/'+city_list[i]+'.html')
sleep(3)
city_name = self.dr.find_element_by_css_selector('.bi_loaction_city').text #定位城市名字
pm_exp = self.dr.find_element_by_css_selector('.pm25_span').text #定位PM2.5指数
air_num = self.dr.find_element_by_css_selector('.bi_aqiarea_num').text #定位AQI指数
air_quality = self.dr.find_element_by_css_selector('.bi_aqiarea_right span').text #定位空气质量描述
pm_info_list.append((city_name, pm_exp, air_num, air_quality))
i += 1
pm_info_list.sort(key=lambda x:float(x[2])) #按AQI指数排序(AQI指数决定了空气质量的优良)
return pm_info_list

def get_pm_info_file(self):
self.file_title = '北上广深成五地PM2.5数据信息'
self.file = open(self.file_title + '.txt', 'wb')
self.floor = 1
for item in self.pm25_info:
separate_line = '**********' + 'TOP' + str(self.floor) + '**********\n'
self.file.write(separate_line.encode('utf-8'))
self.file.write(('城市：' + item[0] + '\n'
'PM2.5指数：' + item[1] + ' '+ '微克/立方米' + '\n'
'AQI指数：' + item[2] + '\n'
'空气质量：' + item[3]+ '\n').encode('utf-8'))
self.floor += 1
self.file.close()

def quit(self):
self.dr.quit()

if __name__ == '__main__':
pm_info = PM()
pm_info.get_pm_info_file()
pm_info.quit()