我正在编写一个给定 http 地址的小程序,它会找到并下载其中的图像。我现在的情况是这样的:
import urllib2, html
class HTMLNode(object):
    def __init__(self,tag,attr,content,closed=True):
        self.tag = tag
        self.attr = attr
        self.content = content
        self.closed = closed
    def istext(self):
        return self.tag == '_text_'
    def tostring(self):
        if self.istext(): 
            return self.content
        ret = '<'+self.tag
        for k, v in self.attr.items():
            ret += ' '+k+'="'+v+'"'
        ret += '>'
        if self.closed:
            for c in self.content:
                ret += c.tostring()
            ret += '</'+self.tag+'>'
        return ret
    def find_by_tag(self,tag):
            ret = []
            if self.tag == tag: ret += [self]
            if not self.istext():
                for c in self.content:
                    ret += c.find_by_tag(tag)
            return ret
def imagegrab(url):
    req = urllib2.Request(url)
    response = urllib2.urlopen(req)
    output = open(url, 'wb')
    output.write(response.read())
缺少的链接正在寻找一种使用 HTMLNode 类的“find_by_tag”功能的方法,以便程序扫描“”标签并从网站下载图片。有人可以帮我吗?