python抓取WEB页面

[songrongu111]

retval=urlretrieve(url)[0] 不知道是什么意思 能不能解释下


from urllib import urlretrieve

def firstNonBlank(lines):
for eachline in lines:
if not eachline.strip():
continue
else:
return eachline

def firstlast(webpage):
f=open(webpage)
lines=f.readlines()
f.close()
print firstNonBlank(lines),
lines.reverse()
print firstNonBlank(lines),


def download(url='http://www.xiaonei.com',
process=firstlast):

try:
retval=urlretrieve(url)[0]
except IOError:
retval=None
if retval:
process(retval)


if __name__=='__main__':
download()

[DarkChampion]

文档对urlretrieve返回的解释：
Copy a network object denoted by a URL to a local file, if necessary. If the URL points to a local file, or a valid cached copy of the object exists, the object is not copied.
Return a tuple (filename, headers) where filename is the local file name under which the object can be found, and headers is whatever the info() method of the object returned by urlopen() returned

就是说返回一个元组，第一个是缓存的本地文件名

[evan007]

学习了，顶个

[zouhailin]

这么强大
好好学学

[lioujian47]

这里看看
http://bbs.chinaunix.net/archiver/?tid-1029403.html

[guangboo]

学习了。
=====
http://www.klipdas.com

[BLwei]

retval=urlretrieve(url)[0]=(filename, headers)[0]=filename

[songrongu111]

结贴了