python - 实时网页抓取

Question

我目前正在使用 BeautifulSoup 进行网络抓取，它是在 xml 中获取和编写的，如下面的代码所示，我只是想知道我该怎么做才能使其实时，因为网站每 5 分钟更新一次。

import csv
import requests
from bs4 import BeautifulSoup

url = 'http://www.dublincity.ie/dublintraffic/cpdata.xml?1543254514266'

res = requests.get(url)
soup = BeautifulSoup(res.content,"xml")
data = []
for item in soup.select("carpark"):
    ditem = {}
    ditem['Name'] = item.get("name")
    ditem['Spaces'] = item.get("spaces")
    data.append(ditem)

with open("xmldocs.csv","w",newline="") as f:
    writer = csv.DictWriter(f,["Name","Spaces"])
    writer.writeheader()
    for info in data:
        writer.writerow(info)

Answer 1

您可以使用 while循环，然后在最后你可以添加一个 sleep 5 分钟。

使用您的示例，这将是:

import csv
import requests
from bs4 import BeautifulSoup
import time

while True:
    url = 'http://www.dublincity.ie/dublintraffic/cpdata.xml?1543254514266'

    res = requests.get(url)
    soup = BeautifulSoup(res.content,"xml")
    data = []
    for item in soup.select("carpark"):
        ditem = {}
        ditem['Name'] = item.get("name")
        ditem['Spaces'] = item.get("spaces")
        data.append(ditem)

    with open("xmldocs.csv","w",newline="") as f:
        writer = csv.DictWriter(f,["Name","Spaces"])
        writer.writeheader()
        for info in data:
            writer.writerow(info)

    time.sleep(5 * 60)