爬虫，值得借鉴的小代码块

考虑异常值

思路

有些程序在运行的时候，如果没有考虑异常值，就会运行出错，因此，在写代码的时候就要考虑到异常值的出现。用try-except处理，推荐敲代码之前，先画一个思路图

代码

from urllib.request import urlopen
from urllib.error import HTTPError
from bs4 import BeautifulSoup


def getTitle(url):
    try:
        html = urlopen(url)
    except HTTPError as e:
        return None
    try:
        bsObj = BeautifulSoup(html.read(), "lxml")
        title = bsObj.body.h1
    except AttributeError as e:
        return None
    return title


title = getTitle("http://www.pythonscraping.com/pages/page1.html")
if title == None:
    print("Title could not be found")
else:
    print(title)

待持续补充