Question

我已经使用python在类中创建了一个scipt来从网页中收集问题链接。我在脚本中使用了❯ k get nodes -o wide NAME STATUS ROLES AGE VERSION INTERNAL-IP EXTERNAL-IP OS-IMAGE KERNEL-VERSION CONTAINER-RUNTIME aks-nodepool1-32797235-0 Ready agent 4h v1.11.4 10.240.0.4 <none> Ubuntu 16.04.5 LTS 4.15.0-1030-azure docker://3.0.1 aks-nodepool1-32797235-3 Ready agent 4h v1.11.4 10.240.0.6 <none> Ubuntu 16.04.5 LTS 4.15.0-1030-azure docker://3.0.1 ❯ ks get pods -o wide NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE cluster-autoscaler-84984799fd-22j42 1/1 Running 0 2h 10.244.1.5 aks-nodepool1-32797235-3 <none> heapster-5d6f9b846c-g7qb8 2/2 Running 0 1h 10.244.0.16 aks-nodepool1-32797235-0 <none> kube-dns-v20-598f8b78ff-8pshc 4/4 Running 0 3h 10.244.1.4 aks-nodepool1-32797235-3 <none> kube-dns-v20-598f8b78ff-plfv8 4/4 Running 0 1h 10.244.0.15 aks-nodepool1-32797235-0 <none> kube-proxy-fjvjv 1/1 Running 0 1h 10.240.0.6 aks-nodepool1-32797235-3 <none> kube-proxy-szr8z 1/1 Running 0 1h 10.240.0.4 aks-nodepool1-32797235-0 <none> kube-svc-redirect-2rhvg 2/2 Running 0 4h 10.240.0.4 aks-nodepool1-32797235-0 <none> kube-svc-redirect-r2m4r 2/2 Running 0 4h 10.240.0.6 aks-nodepool1-32797235-3 <none> kubernetes-dashboard-68f468887f-c8p78 1/1 Running 0 4h 10.244.0.7 aks-nodepool1-32797235-0 <none> metrics-server-5cbc77f79f-44f9w 1/1 Running 0 4h 10.244.0.3 aks-nodepool1-32797235-0 <none> tiller-deploy-57f988f854-z9qln 1/1 Running 0 4h 10.244.0.8 aks-nodepool1-32797235-0 <none> tunnelfront-7cf9d447f9-56g7k 1/1 Running 0 4h 10.244.0.2 aks-nodepool1-32797235-0 <none>方法来打印结果。但是，当我尝试打印它时，输出为None。

这里的主要目的是使__str__()此方法在我的以下脚本中起作用。

我要去哪里了，该如何解决？

__str__()

Answer 1

您没有打印正确的东西。请检查文档，了解如何使用此类方法。

crawler = DataSourcer(URL)
crawler.fetch() 
print(crawler)

Answer 2

您的方法很好，看来您打印不正确。您正在打印crawler.fetch()，它返回None。

import requests
from urllib.parse import urljoin
from bs4 import BeautifulSoup

URL = "https://stackoverflow.com/questions/tagged/web-scraping"

class DataSourcer:

    def __init__(self,link):
        self.link = link
        self.datalist = []

    def fetch(self):
        res = requests.get(self.link)
        soup = BeautifulSoup(res.text,"lxml")
        for ilink in soup.select(".summary .question-hyperlink"):
            self.datalist.append(urljoin(self.link,ilink.get("href")))

    def __str__(self):
        return self.datalist

if __name__ == '__main__':    
    crawler = DataSourcer(URL)
    crawler.fetch()
    print(crawler.__str__())

Answer 3

print（crawler.fetch（））将打印fetch（）方法的返回值（没有返回值）您应该做的是：

crawler.fetch()
print(crawler)

无法让我的脚本打印结果

3 个答案: