for loop in function, While 真正难懂

Question

我将这个简单的 Web Weather Scraping 脚本放在一起，以检查给定位置的温度。该代码可以完美运行，尽管它可能不是最好的或最干净的版本。还在学习。但它正在抓取：<span _ngcontent-c19="" class="wu-value wu-value-to">67</span> from HERE。

#!/usr/bin/python
# -*- coding: utf-8 -*-

import requests
from BeautifulSoup import BeautifulSoup
import time

degree = u'\N{DEGREE SIGN}'

url = 'https://www.wunderground.com/weather/us/ca/san-diego/KCASANDI355'

response = requests.get(url)
html = response.content
soup = BeautifulSoup(html)
current_temp = soup.find("div", {"class" : "current-temp"}).find("span", {"class" : "wu-value wu-value-to"})

for i in current_temp:
    print('San Diego Feels Like ') + i + (degree + 'F')

输出如下所示：

San Diego Feels Like 74°F

我的目标是拥有一个循环函数，并根据 current_temp 变量中定义的当前温度进行打印，例如，如果温度低于 70F It's too cold，或者如果它超过 80F It is too hot，等等。但是我有一个问题要了解如何告诉我的代码执行，或者在这种情况下 print 您可以说这些不同的任务或方法？。请原谅我的英语。 While (True): 循环肯定有问题，但我无法理解它。感谢您的帮助，祝大家星期天愉快。

#!/usr/bin/python
import requests
from BeautifulSoup import BeautifulSoup
import time

degree = u'\N{DEGREE SIGN}'

url = 'https://www.wunderground.com/weather/us/ca/san-diego/KCASANDI355'

response = requests.get(url)
html = response.content
soup = BeautifulSoup(html)
current_temp = soup.find("div", {"class" : "current-temp"}).find("span", {"class" : "wu-value wu-value-to"})

def weather():
    while(True):
        for i in current_temp:
            print('San Diego Feels Like ') + i + (degree + 'F')
            #time.sleep(2)
        if (i <= 70) and (i >= 50):
            print('It\'s kinda cool')
            break
        elif i <= 50:
            print('It\'s cold af')
        elif (i >= 80) and (i <= 100):
            print('It\'s hot af')
            break
        else:
            print('You Dead')
            break
if __name__ == "__main__":
    weather()

Answer 1

首先，您正在收集整个 <span> 标签，即使您只对显示的值感兴趣，所以要获取温度值（并将其转换为实际整数），请执行以下操作：

current_temp = int(soup.find("div", {"class": "current-temp"}).find(
    "span", {"class": "wu-value wu-value-to"}).getText())

其次，你的current_temp一旦获得就永远不会改变，你想要的是定期获取最新的温度值，然后根据它的值打印你想要的任何东西。类似于：

# !/usr/bin/python
import requests
from BeautifulSoup import BeautifulSoup
import time

degree = u'\N{DEGREE SIGN}'
url = 'https://www.wunderground.com/weather/us/ca/san-diego/KCASANDI355'

def weather():
    while (True):
        # get the current temperature
        response = requests.get(url)
        soup = BeautifulSoup(response.content)
        current_temp = int(soup.find("div", {"class": "current-temp"}).find(
            "span", {"class": "wu-value wu-value-to"}).getText())
        # now print it out and add our comment
        print(u"San Diego Feels Like: {}{}F".format(current_temp, degree))
        if current_temp > 100:
            print("You Dead")
        elif 100 >= current_temp > 80:
            print("It's hot af")
        elif 80 >= current_temp > 70:
            print("It's just right")
        elif 70 >= current_temp > 50:
            print("It's kinda cool")
        else:
            print("It's cold af")
        # finally, wait 5 minutes (300 seconds) before updating again
        time.sleep(300)

if __name__ == "__main__":
    weather()

for loop in function, While 真正难懂

For loop in function, While true difficulty to understand

python

for-loop

beautifulsoup

web-scraping