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Make a new urllib package .

Browse source 
It consists of code from urllib, urllib2, urlparse, and robotparser.
The old modules have all been removed.  The new package has five
submodules: urllib.parse, urllib.request, urllib.response,
urllib.error, and urllib.robotparser.  The urllib.request.urlopen()
function uses the url opener from urllib2.

Note that the unittests have not been renamed for the
beta, but they will be renamed in the future.

Joint work with Senthil Kumaran.
This commit is contained in:
Jeremy Hylton 2008-06-18 20:49:58 +00:00
parent a656d2cd89
commit 1afc169616
40 changed files with 3190 additions and 3536 deletions
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212
Lib/robotparser.py
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@ -1,212 +0,0 @@
""" robotparser.py
Copyright (C) 2000 Bastian Kleineidam
You can choose between two licenses when using this package:
1) GNU GPLv2
2) PSF license for Python 2.2
The robots.txt Exclusion Protocol is implemented as specified in
http://info.webcrawler.com/mak/projects/robots/norobots-rfc.html
"""
import urlparse
import urllib
__all__ = ["RobotFileParser"]
class RobotFileParser:
""" This class provides a set of methods to read, parse and answer
questions about a single robots.txt file.
"""
def __init__(self, url=''):
self.entries = []
self.default_entry = None
self.disallow_all = False
self.allow_all = False
self.set_url(url)
self.last_checked = 0
def mtime(self):
"""Returns the time the robots.txt file was last fetched.
This is useful for long-running web spiders that need to
check for new robots.txt files periodically.
"""
return self.last_checked
def modified(self):
"""Sets the time the robots.txt file was last fetched to the
current time.
"""
import time
self.last_checked = time.time()
def set_url(self, url):
"""Sets the URL referring to a robots.txt file."""
self.url = url
self.host, self.path = urlparse.urlparse(url)[1:3]
def read(self):
"""Reads the robots.txt URL and feeds it to the parser."""
opener = URLopener()
f = opener.open(self.url)
lines = []
line = f.readline()
while line:
lines.append(line.strip())
line = f.readline()
self.errcode = opener.errcode
if self.errcode in (401, 403):
self.disallow_all = True
elif self.errcode >= 400:
self.allow_all = True
elif self.errcode == 200 and lines:
self.parse(lines)
def _add_entry(self, entry):
if "*" in entry.useragents:
# the default entry is considered last
self.default_entry = entry
else:
self.entries.append(entry)
def parse(self, lines):
"""parse the input lines from a robots.txt file.
We allow that a user-agent: line is not preceded by
one or more blank lines."""
state = 0
linenumber = 0
entry = Entry()
for line in lines:
linenumber = linenumber + 1
if not line:
if state == 1:
entry = Entry()
state = 0
elif state == 2:
self._add_entry(entry)
entry = Entry()
state = 0
# remove optional comment and strip line
i = line.find('#')
if i >= 0:
line = line[:i]
line = line.strip()
if not line:
continue
line = line.split(':', 1)
if len(line) == 2:
line[0] = line[0].strip().lower()
line[1] = urllib.unquote(line[1].strip())
if line[0] == "user-agent":
if state == 2:
self._add_entry(entry)
entry = Entry()
entry.useragents.append(line[1])
state = 1
elif line[0] == "disallow":
if state != 0:
entry.rulelines.append(RuleLine(line[1], False))
state = 2
elif line[0] == "allow":
if state != 0:
entry.rulelines.append(RuleLine(line[1], True))
if state == 2:
self.entries.append(entry)
def can_fetch(self, useragent, url):
"""using the parsed robots.txt decide if useragent can fetch url"""
if self.disallow_all:
return False
if self.allow_all:
return True
# search for given user agent matches
# the first match counts
url = urllib.quote(urlparse.urlparse(urllib.unquote(url))[2]) or "/"
for entry in self.entries:
if entry.applies_to(useragent):
return entry.allowance(url)
# try the default entry last
if self.default_entry:
return self.default_entry.allowance(url)
# agent not found ==> access granted
return True
def __str__(self):
return ''.join([str(entry) + "\n" for entry in self.entries])
class RuleLine:
"""A rule line is a single "Allow:" (allowance==True) or "Disallow:"
(allowance==False) followed by a path."""
def __init__(self, path, allowance):
if path == '' and not allowance:
# an empty value means allow all
allowance = True
self.path = urllib.quote(path)
self.allowance = allowance
def applies_to(self, filename):
return self.path == "*" or filename.startswith(self.path)
def __str__(self):
return (self.allowance and "Allow" or "Disallow") + ": " + self.path
class Entry:
"""An entry has one or more user-agents and zero or more rulelines"""
def __init__(self):
self.useragents = []
self.rulelines = []
def __str__(self):
ret = []
for agent in self.useragents:
ret.extend(["User-agent: ", agent, "\n"])
for line in self.rulelines:
ret.extend([str(line), "\n"])
return ''.join(ret)
def applies_to(self, useragent):
"""check if this entry applies to the specified agent"""
# split the name token and make it lower case
useragent = useragent.split("/")[0].lower()
for agent in self.useragents:
if agent == '*':
# we have the catch-all agent
return True
agent = agent.lower()
if agent in useragent:
return True
return False
def allowance(self, filename):
"""Preconditions:
- our agent applies to this entry
- filename is URL decoded"""
for line in self.rulelines:
if line.applies_to(filename):
return line.allowance
return True
class URLopener(urllib.FancyURLopener):
def __init__(self, *args):
urllib.FancyURLopener.__init__(self, *args)
self.errcode = 200
def prompt_user_passwd(self, host, realm):
## If robots.txt file is accessible only with a password,
## we act as if the file wasn't there.
return None, None
def http_error_default(self, url, fp, errcode, errmsg, headers):
self.errcode = errcode
return urllib.FancyURLopener.http_error_default(self, url, fp, errcode,
errmsg, headers)