Python 3 抓取网页资源的 N 种方法

import urllib.request
response = urllib.request.urlopen( ' http://python.org/ ')
html = response.read()

import urllib.request

req = urllib.request.Request( ' http://python.org/ ')
response = urllib.request.urlopen(req)
the_page = response.read()

# ! /usr/bin/env python3

import urllib.parse
import urllib.request

url = ' http://localhost/login.php '
user_agent = ' Mozilla/4.0 (compatible; MSIE 5.5; Windows NT) '
values = {
' act ' : ' login ',
' login[email] ' : ' yzhang@i9i8.com ',
' login[password] ' : ' 123456 '
}

data = urllib.parse.urlencode(values)
req = urllib.request.Request(url, data)
req.add_header( ' Referer ', ' http://www.python.org/ ')
response = urllib.request.urlopen(req)
the_page = response.read()

print(the_page.decode( " utf8 "))

# ! /usr/bin/env python3

import urllib.parse
import urllib.request

url = ' http://localhost/login.php '
user_agent = ' Mozilla/4.0 (compatible; MSIE 5.5; Windows NT) '
values = {
' act ' : ' login ',
' login[email] ' : ' yzhang@i9i8.com ',
' login[password] ' : ' 123456 '
}
headers = { ' User-Agent ' : user_agent }

data = urllib.parse.urlencode(values)
req = urllib.request.Request(url, data, headers)
response = urllib.request.urlopen(req)
the_page = response.read()

print(the_page.decode( " utf8 "))

# ! /usr/bin/env python3

from urllib.request import Request, urlopen
from urllib.error import URLError, HTTPError
req = Request( " http://twitter.com/ ")
try:
response = urlopen(req)
except HTTPError as e:
print( ' The server couldn\'t fulfill the request. ')
print( ' Error code: ', e.code)
except URLError as e:
print( ' We failed to reach a server. ')
print( ' Reason: ', e.reason)
else:
print( " good! ")
print(response.read().decode( " utf8 "))

# ! /usr/bin/env python3

from urllib.request import Request, urlopen
from urllib.error import URLError
req = Request( " http://twitter.com/ ")
try:
response = urlopen(req)
except URLError as e:
if hasattr(e, ' reason '):
print( ' We failed to reach a server. ')
print( ' Reason: ', e.reason)
elif hasattr(e, ' code '):
print( ' The server couldn\'t fulfill the request. ')
print( ' Error code: ', e.code)
else:
print( " good! ")
print(response.read().decode( " utf8 "))

# ! /usr/bin/env python3

import urllib.request

# create a password manager
password_mgr = urllib.request.HTTPPasswordMgrWithDefaultRealm()

# Add the username and password.
# If we knew the realm, we could use it instead of None.
top_level_url = " https://cms.tetx.com/ "
password_mgr.add_password(None, top_level_url, ' yzhang ', ' cccddd ')

handler = urllib.request.HTTPBasicAuthHandler(password_mgr)

# create "opener" (OpenerDirector instance)
opener = urllib.request.build_opener(handler)

# use the opener to fetch a URL
a_url = " https://cms.tetx.com/ "
x = opener.open(a_url)
print(x.read())

# Install the opener.
# Now all calls to urllib.request.urlopen use our opener.
urllib.request.install_opener(opener)

a = urllib.request.urlopen(a_url).read().decode( ' utf8 ')
print(a)

# ! /usr/bin/env python3

import socket
import urllib.request

# timeout in seconds
timeout = 2
socket.setdefaulttimeout(timeout)

# this call to urllib.request.urlopen now uses the default timeout
# we have set in the socket module
req = urllib.request.Request( ' http://twitter.com/ ')
a = urllib.request.urlopen(req).read()
print(a)