在看python核心编程第三版的时候遇到的问题
```import io
import formatter
from html.parser import HTMLParser
import http
import os
import sys
import urllib.request
from urllib.parse import urlparse,urljoin
class Retriever(object):
slots=('url','file')
def init(self,url):
self.url,self.file=self.get_file(url)
def get_file(self,url,default='index.html'):
'Create usable local filename from URL'
parsed=urlparse(url)
host=parsed.netloc.split('@')[-1].split(':')[0]
filepath='%s%s' % (host,parsed.path)
if not os.path.splitext(parsed.path)[1]:
filepath=os.path.join(filepath,default)
linkdir=os.path.dirname(filepath)
if not os.path.isdir(linkdir):
if os.path.exists(linkdir):
os.unlink(linkdir)
os.makedirs(linkdir)
return url,filepath
def download(self):
'Download URL to specific named file'
try:
retval=urllib.request.urlretrieve(self.url,self.file)
except (IOError,httplib.InvalidURL) as e:
retval=(('*** ERROR: bad URL "%s": %s' % (self.url, e)),)
return retval
def parse_links(self):
'Parse out the links found in download HTML file'
f=open(self.file,'rb')
data=f.read()
f.close()
parser=HTMLParser(formatter.AbstractFormatter(formatter.DumbWriter(io.StringIO())))
parser.feed(data)
parser.close()
return parser.anchorlist
class Crawler(object):
count=0
def __init__(self, url):
self.q=[url]
self.seen=set()
parsed=urlparse(url)
host=parsed.netloc.split('@')[-1].split(':')[0]
self.dom='.'.join(host.split('.')[-2:])
def get_page(self, url, media=False):
'Download page & parse links, add to queue if nec'
r=Retriever(url)
fname=r.download()[0]
if fname[0] == '*':
print(fname,'...skipping parse')
return
Crawler.count += 1
print('\n(',Crawler.count,')')
print('URL:',url)
print('FILE:',fname)
self.seen.add(url)
ftype=os.path.splitext(fname)[1]
if ftype not in ('.htm', '.html'):
return
for link in r.parse_links():
if link.startswith('mailto:'):
print('...discarded, mailto link')
continue
if not media:
ftype=os.path.splitext(link)[1]
if ftype in ('.mp3', '.mp4', '.m4v', '.wav'):
print('...discarded, media file')
continue
if not link.startswith('http://'):
link=urljoin(url,link)
print('*',link)
if link not in self.seen:
if self.dom not in link:
print('...discarded, not in domain')
else:
if link not in self.q:
self.q.append(link)
print('...new, added to Q')
else:
print('...discarded, already in Q')
else:
print('...discarded, already processed')
def go(self,media=False):
'Process next page in queue (if any)'
while self.q:
url=self.q.pop()
self.get_page(url,media)
def main():
if len(sys.argv) > 1:
url=sys.argv[1]
else:
try:
url=input('Enter starting URL: ')
except (KeyboardInterrupt, EOFError):
url=''
if not url:
return
if not url.startswith('http://') and not url.startswith('ftp://'):
url='http://%s/' % url
robot=Crawler(url)
robot.go()
if name=='__main__':
main()
这里报错HTMLParser的__init__()需要一个位置参数而给了它两个
看了下文档，好像这个类只有一个关键字参数，给的例子也是先自定义一个子类再实例化，那么书上这么写是什么意思？要怎么改？求解答
