| """An extensible library for opening URLs using a variety of protocols |
| |
| The simplest way to use this module is to call the urlopen function, |
| which accepts a string containing a URL or a Request object (described |
| below). It opens the URL and returns the results as file-like |
| object; the returned object has some extra methods described below. |
| |
| The OpenerDirectory manages a collection of Handler objects that do |
| all the actual work. Each Handler implements a particular protocol or |
| option. The OpenerDirector is a composite object that invokes the |
| Handlers needed to open the requested URL. For example, the |
| HTTPHandler performs HTTP GET and POST requests and deals with |
| non-error returns. The HTTPRedirectHandler automatically deals with |
| HTTP 301 & 302 redirect errors, and the HTTPDigestAuthHandler deals |
| with digest authentication. |
| |
| urlopen(url, data=None) -- basic usage is that same as original |
| urllib. pass the url and optionally data to post to an HTTP URL, and |
| get a file-like object back. One difference is that you can also pass |
| a Request instance instead of URL. Raises a URLError (subclass of |
| IOError); for HTTP errors, raises an HTTPError, which can also be |
| treated as a valid response. |
| |
| build_opener -- function that creates a new OpenerDirector instance. |
| will install the default handlers. accepts one or more Handlers as |
| arguments, either instances or Handler classes that it will |
| instantiate. if one of the argument is a subclass of the default |
| handler, the argument will be installed instead of the default. |
| |
| install_opener -- installs a new opener as the default opener. |
| |
| objects of interest: |
| OpenerDirector -- |
| |
| Request -- an object that encapsulates the state of a request. the |
| state can be a simple as the URL. it can also include extra HTTP |
| headers, e.g. a User-Agent. |
| |
| BaseHandler -- |
| |
| exceptions: |
| URLError-- a subclass of IOError, individual protocols have their own |
| specific subclass |
| |
| HTTPError-- also a valid HTTP response, so you can treat an HTTP error |
| as an exceptional event or valid response |
| |
| internals: |
| BaseHandler and parent |
| _call_chain conventions |
| |
| Example usage: |
| |
| import urllib2 |
| |
| # set up authentication info |
| authinfo = urllib2.HTTPBasicAuthHandler() |
| authinfo.add_password('realm', 'host', 'username', 'password') |
| |
| # build a new opener that adds authentication and caching FTP handlers |
| opener = urllib2.build_opener(authinfo, urllib2.CacheFTPHandler) |
| |
| # install it |
| urllib2.install_opener(opener) |
| |
| f = urllib2.urlopen('http://www.python.org/') |
| |
| |
| """ |
| |
| # XXX issues: |
| # If an authentication error handler that tries to perform |
| # authentication for some reason but fails, how should the error be |
| # signalled? The client needs to know the HTTP error code. But if |
| # the handler knows that the problem was, e.g., that it didn't know |
| # that hash algo that requested in the challenge, it would be good to |
| # pass that information along to the client, too. |
| |
| # XXX to do: |
| # name! |
| # documentation (getting there) |
| # complex proxies |
| # abstract factory for opener |
| # ftp errors aren't handled cleanly |
| # gopher can return a socket.error |
| # check digest against correct (i.e. non-apache) implementation |
| |
| import string |
| import socket |
| import UserDict |
| import httplib |
| import re |
| import base64 |
| import types |
| import urlparse |
| import os |
| import md5 |
| import mimetypes |
| import mimetools |
| import ftplib |
| import sys |
| import time |
| import gopherlib |
| |
| try: |
| from cStringIO import StringIO |
| except ImportError: |
| from StringIO import StringIO |
| |
| try: |
| import sha |
| except ImportError: |
| # need 1.5.2 final |
| sha = None |
| |
| # not sure how many of these need to be gotten rid of |
| from urllib import unwrap, unquote, splittype, splithost, \ |
| addinfourl, splitport, splitgophertype, splitquery, \ |
| splitattr, ftpwrapper, noheaders |
| |
| # support for proxies via environment variables |
| from urllib import getproxies |
| |
| # support for FileHandler |
| from urllib import localhost, thishost, url2pathname, pathname2url |
| |
| # support for GopherHandler |
| from urllib import splitgophertype, splitquery |
| |
| __version__ = "2.0a1" |
| |
| _opener = None |
| def urlopen(url, data=None): |
| global _opener |
| if _opener is None: |
| _opener = build_opener() |
| return _opener.open(url, data) |
| |
| def install_opener(opener): |
| global _opener |
| _opener = opener |
| |
| # do these error classes make sense? |
| # make sure all of the IOError stuff is overridden. we just want to be |
| # subtypes. |
| |
| class URLError(IOError): |
| # URLError is a sub-type of IOError, but it doesn't share any of |
| # the implementation. need to override __init__ and __str__ |
| def __init__(self, reason): |
| self.reason = reason |
| |
| def __str__(self): |
| return '<urlopen error %s>' % self.reason |
| |
| class HTTPError(URLError, addinfourl): |
| """Raised when HTTP error occurs, but also acts like non-error return""" |
| __super_init = addinfourl.__init__ |
| |
| def __init__(self, url, code, msg, hdrs, fp): |
| self.__super_init(fp, hdrs, url) |
| self.code = code |
| self.msg = msg |
| self.hdrs = hdrs |
| self.fp = fp |
| # XXX |
| self.filename = url |
| |
| def __str__(self): |
| return 'HTTP Error %s: %s' % (self.code, self.msg) |
| |
| def __del__(self): |
| # XXX is this safe? what if user catches exception, then |
| # extracts fp and discards exception? |
| if self.fp: |
| self.fp.close() |
| |
| class GopherError(URLError): |
| pass |
| |
| class Request: |
| def __init__(self, url, data=None, headers={}): |
| # unwrap('<URL:type://host/path>') --> 'type://host/path' |
| self.__original = unwrap(url) |
| self.type = None |
| # self.__r_type is what's left after doing the splittype |
| self.host = None |
| self.port = None |
| self.data = data |
| self.headers = {} |
| self.headers.update(headers) |
| |
| def __getattr__(self, attr): |
| # XXX this is a fallback mechanism to guard against these |
| # methods getting called in a non-standard order. this may be |
| # too complicated and/or unnecessary. |
| # XXX should the __r_XXX attributes be public? |
| if attr[:12] == '_Request__r_': |
| name = attr[12:] |
| if hasattr(Request, 'get_' + name): |
| getattr(self, 'get_' + name)() |
| return getattr(self, attr) |
| raise AttributeError, attr |
| |
| def add_data(self, data): |
| self.data = data |
| |
| def has_data(self): |
| return self.data is not None |
| |
| def get_data(self): |
| return self.data |
| |
| def get_full_url(self): |
| return self.__original |
| |
| def get_type(self): |
| if self.type is None: |
| self.type, self.__r_type = splittype(self.__original) |
| assert self.type is not None, self.__original |
| return self.type |
| |
| def get_host(self): |
| if self.host is None: |
| self.host, self.__r_host = splithost(self.__r_type) |
| if self.host: |
| self.host = unquote(self.host) |
| return self.host |
| |
| def get_selector(self): |
| return self.__r_host |
| |
| def set_proxy(self, proxy): |
| self.__proxy = proxy |
| # XXX this code is based on urllib, but it doesn't seem |
| # correct. specifically, if the proxy has a port number then |
| # splittype will return the hostname as the type and the port |
| # will be include with everything else |
| self.type, self.__r_type = splittype(self.__proxy) |
| self.host, XXX = splithost(self.__r_type) |
| self.host = unquote(self.host) |
| self.__r_host = self.__original |
| |
| def add_header(self, key, val): |
| # useful for something like authentication |
| self.headers[key] = val |
| |
| class OpenerDirector: |
| def __init__(self): |
| server_version = "Python-urllib/%s" % __version__ |
| self.addheaders = [('User-agent', server_version)] |
| # manage the individual handlers |
| self.handlers = [] |
| self.handle_open = {} |
| self.handle_error = {} |
| |
| def add_handler(self, handler): |
| added = 0 |
| for meth in get_methods(handler): |
| if meth[-5:] == '_open': |
| protocol = meth[:-5] |
| if self.handle_open.has_key(protocol): |
| self.handle_open[protocol].append(handler) |
| else: |
| self.handle_open[protocol] = [handler] |
| added = 1 |
| continue |
| i = string.find(meth, '_') |
| j = string.find(meth[i+1:], '_') + i + 1 |
| if j != -1 and meth[i+1:j] == 'error': |
| proto = meth[:i] |
| kind = meth[j+1:] |
| try: |
| kind = string.atoi(kind) |
| except ValueError: |
| pass |
| dict = self.handle_error.get(proto, {}) |
| if dict.has_key(kind): |
| dict[kind].append(handler) |
| else: |
| dict[kind] = [handler] |
| self.handle_error[proto] = dict |
| added = 1 |
| continue |
| if added: |
| self.handlers.append(handler) |
| handler.add_parent(self) |
| |
| def __del__(self): |
| self.close() |
| |
| def close(self): |
| for handler in self.handlers: |
| handler.close() |
| self.handlers = [] |
| |
| def _call_chain(self, chain, kind, meth_name, *args): |
| # XXX raise an exception if no one else should try to handle |
| # this url. return None if you can't but someone else could. |
| handlers = chain.get(kind, ()) |
| for handler in handlers: |
| func = getattr(handler, meth_name) |
| |
| result = func(*args) |
| if result is not None: |
| return result |
| |
| def open(self, fullurl, data=None): |
| # accept a URL or a Request object |
| if type(fullurl) == types.StringType: |
| req = Request(fullurl, data) |
| else: |
| req = fullurl |
| if data is not None: |
| req.add_data(data) |
| assert isinstance(req, Request) # really only care about interface |
| |
| result = self._call_chain(self.handle_open, 'default', |
| 'default_open', req) |
| if result: |
| return result |
| |
| type_ = req.get_type() |
| result = self._call_chain(self.handle_open, type_, type_ + \ |
| '_open', req) |
| if result: |
| return result |
| |
| return self._call_chain(self.handle_open, 'unknown', |
| 'unknown_open', req) |
| |
| def error(self, proto, *args): |
| if proto == 'http': |
| # XXX http protocol is special cased |
| dict = self.handle_error[proto] |
| proto = args[2] # YUCK! |
| meth_name = 'http_error_%d' % proto |
| http_err = 1 |
| orig_args = args |
| else: |
| dict = self.handle_error |
| meth_name = proto + '_error' |
| http_err = 0 |
| args = (dict, proto, meth_name) + args |
| result = self._call_chain(*args) |
| if result: |
| return result |
| |
| if http_err: |
| args = (dict, 'default', 'http_error_default') + orig_args |
| return self._call_chain(*args) |
| |
| def is_callable(obj): |
| # not quite like builtin callable (which I didn't know existed), |
| # not entirely sure it needs to be different |
| if type(obj) in (types.BuiltinFunctionType, |
| types.BuiltinMethodType, types.LambdaType, |
| types.MethodType): |
| return 1 |
| if type(obj) == types.InstanceType: |
| return hasattr(obj, '__call__') |
| return 0 |
| |
| def get_methods(inst): |
| methods = {} |
| classes = [] |
| classes.append(inst.__class__) |
| while classes: |
| klass = classes[0] |
| del classes[0] |
| classes = classes + list(klass.__bases__) |
| for name in dir(klass): |
| attr = getattr(klass, name) |
| if type(attr) == types.UnboundMethodType: |
| methods[name] = 1 |
| for name in dir(inst): |
| if is_callable(getattr(inst, name)): |
| methods[name] = 1 |
| return methods.keys() |
| |
| # XXX probably also want an abstract factory that knows things like |
| # the fact that a ProxyHandler needs to get inserted first. |
| # would also know when it makes sense to skip a superclass in favor of |
| # a subclass and when it might make sense to include both |
| |
| def build_opener(*handlers): |
| """Create an opener object from a list of handlers. |
| |
| The opener will use several default handlers, including support |
| for HTTP and FTP. If there is a ProxyHandler, it must be at the |
| front of the list of handlers. (Yuck.) |
| |
| If any of the handlers passed as arguments are subclasses of the |
| default handlers, the default handlers will not be used. |
| """ |
| |
| opener = OpenerDirector() |
| default_classes = [ProxyHandler, UnknownHandler, HTTPHandler, |
| HTTPDefaultErrorHandler, HTTPRedirectHandler, |
| FTPHandler, FileHandler] |
| skip = [] |
| for klass in default_classes: |
| for check in handlers: |
| if type(check) == types.ClassType: |
| if issubclass(check, klass): |
| skip.append(klass) |
| elif type(check) == types.InstanceType: |
| if isinstance(check, klass): |
| skip.append(klass) |
| for klass in skip: |
| default_classes.remove(klass) |
| |
| for klass in default_classes: |
| opener.add_handler(klass()) |
| |
| for h in handlers: |
| if type(h) == types.ClassType: |
| h = h() |
| opener.add_handler(h) |
| return opener |
| |
| class BaseHandler: |
| def add_parent(self, parent): |
| self.parent = parent |
| def close(self): |
| self.parent = None |
| |
| class HTTPDefaultErrorHandler(BaseHandler): |
| def http_error_default(self, req, fp, code, msg, hdrs): |
| raise HTTPError(req.get_full_url(), code, msg, hdrs, fp) |
| |
| class HTTPRedirectHandler(BaseHandler): |
| # Implementation note: To avoid the server sending us into an |
| # infinite loop, the request object needs to track what URLs we |
| # have already seen. Do this by adding a handler-specific |
| # attribute to the Request object. |
| def http_error_302(self, req, fp, code, msg, headers): |
| if headers.has_key('location'): |
| newurl = headers['location'] |
| elif headers.has_key('uri'): |
| newurl = headers['uri'] |
| else: |
| return |
| nil = fp.read() |
| fp.close() |
| |
| newurl = urlparse.urljoin(req.get_full_url(), newurl) |
| |
| # XXX Probably want to forget about the state of the current |
| # request, although that might interact poorly with other |
| # handlers that also use handler-specific request attributes |
| new = Request(newurl, req.get_data()) |
| new.error_302_dict = {} |
| if hasattr(req, 'error_302_dict'): |
| if req.error_302_dict.has_key(newurl): |
| raise HTTPError(req.get_full_url(), code, |
| self.inf_msg + msg, headers) |
| new.error_302_dict.update(req.error_302_dict) |
| new.error_302_dict[newurl] = newurl |
| return self.parent.open(new) |
| |
| http_error_301 = http_error_302 |
| |
| inf_msg = "The HTTP server returned a redirect error that would" \ |
| "lead to an infinite loop.\n" \ |
| "The last 302 error message was:\n" |
| |
| class ProxyHandler(BaseHandler): |
| def __init__(self, proxies=None): |
| if proxies is None: |
| proxies = getproxies() |
| assert hasattr(proxies, 'has_key'), "proxies must be a mapping" |
| self.proxies = proxies |
| for type, url in proxies.items(): |
| setattr(self, '%s_open' % type, |
| lambda r, proxy=url, type=type, meth=self.proxy_open: \ |
| meth(r, proxy, type)) |
| |
| def proxy_open(self, req, proxy, type): |
| orig_type = req.get_type() |
| req.set_proxy(proxy) |
| if orig_type == type: |
| # let other handlers take care of it |
| # XXX this only makes sense if the proxy is before the |
| # other handlers |
| return None |
| else: |
| # need to start over, because the other handlers don't |
| # grok the proxy's URL type |
| return self.parent.open(req) |
| |
| # feature suggested by Duncan Booth |
| # XXX custom is not a good name |
| class CustomProxy: |
| # either pass a function to the constructor or override handle |
| def __init__(self, proto, func=None, proxy_addr=None): |
| self.proto = proto |
| self.func = func |
| self.addr = proxy_addr |
| |
| def handle(self, req): |
| if self.func and self.func(req): |
| return 1 |
| |
| def get_proxy(self): |
| return self.addr |
| |
| class CustomProxyHandler(BaseHandler): |
| def __init__(self, *proxies): |
| self.proxies = {} |
| |
| def proxy_open(self, req): |
| proto = req.get_type() |
| try: |
| proxies = self.proxies[proto] |
| except KeyError: |
| return None |
| for p in proxies: |
| if p.handle(req): |
| req.set_proxy(p.get_proxy()) |
| return self.parent.open(req) |
| return None |
| |
| def do_proxy(self, p, req): |
| p |
| return self.parent.open(req) |
| |
| def add_proxy(self, cpo): |
| if self.proxies.has_key(cpo.proto): |
| self.proxies[cpo.proto].append(cpo) |
| else: |
| self.proxies[cpo.proto] = [cpo] |
| |
| class HTTPPasswordMgr: |
| def __init__(self): |
| self.passwd = {} |
| |
| def add_password(self, realm, uri, user, passwd): |
| # uri could be a single URI or a sequence |
| if type(uri) == types.StringType: |
| uri = [uri] |
| uri = tuple(map(self.reduce_uri, uri)) |
| if not self.passwd.has_key(realm): |
| self.passwd[realm] = {} |
| self.passwd[realm][uri] = (user, passwd) |
| |
| def find_user_password(self, realm, authuri): |
| domains = self.passwd.get(realm, {}) |
| authuri = self.reduce_uri(authuri) |
| for uris, authinfo in domains.items(): |
| for uri in uris: |
| if self.is_suburi(uri, authuri): |
| return authinfo |
| return None, None |
| |
| def reduce_uri(self, uri): |
| """Accept netloc or URI and extract only the netloc and path""" |
| parts = urlparse.urlparse(uri) |
| if parts[1]: |
| return parts[1], parts[2] or '/' |
| else: |
| return parts[2], '/' |
| |
| def is_suburi(self, base, test): |
| """Check if test is below base in a URI tree |
| |
| Both args must be URIs in reduced form. |
| """ |
| if base == test: |
| return 1 |
| if base[0] != test[0]: |
| return 0 |
| common = os.path.commonprefix((base[1], test[1])) |
| if len(common) == len(base[1]): |
| return 1 |
| return 0 |
| |
| |
| class HTTPBasicAuthHandler(BaseHandler): |
| rx = re.compile('[ \t]*([^ \t]+)[ \t]+realm="([^"]*)"') |
| |
| # XXX there can actually be multiple auth-schemes in a |
| # www-authenticate header. should probably be a lot more careful |
| # in parsing them to extract multiple alternatives |
| |
| def __init__(self): |
| self.passwd = HTTPPasswordMgr() |
| self.add_password = self.passwd.add_password |
| self.__current_realm = None |
| # if __current_realm is not None, then the server must have |
| # refused our name/password and is asking for authorization |
| # again. must be careful to set it to None on successful |
| # return. |
| |
| def http_error_401(self, req, fp, code, msg, headers): |
| # XXX could be mult. headers |
| authreq = headers.get('www-authenticate', None) |
| if authreq: |
| mo = HTTPBasicAuthHandler.rx.match(authreq) |
| if mo: |
| scheme, realm = mo.groups() |
| if string.lower(scheme) == 'basic': |
| return self.retry_http_basic_auth(req, realm) |
| |
| def retry_http_basic_auth(self, req, realm): |
| if self.__current_realm is None: |
| self.__current_realm = realm |
| else: |
| self.__current_realm = realm |
| return None |
| # XXX host isn't really the correct URI? |
| host = req.get_host() |
| user,pw = self.passwd.find_user_password(realm, host) |
| if pw: |
| raw = "%s:%s" % (user, pw) |
| auth = string.strip(base64.encodestring(raw)) |
| req.add_header('Authorization', 'Basic %s' % auth) |
| resp = self.parent.open(req) |
| self.__current_realm = None |
| return resp |
| else: |
| self.__current_realm = None |
| return None |
| |
| class HTTPDigestAuthHandler(BaseHandler): |
| """An authentication protocol defined by RFC 2069 |
| |
| Digest authentication improves on basic authentication because it |
| does not transmit passwords in the clear. |
| """ |
| |
| def __init__(self): |
| self.passwd = HTTPPasswordMgr() |
| self.add_password = self.passwd.add_password |
| self.__current_realm = None |
| |
| def http_error_401(self, req, fp, code, msg, headers): |
| # XXX could be mult. headers |
| authreq = headers.get('www-authenticate', None) |
| if authreq: |
| kind = string.split(authreq)[0] |
| if kind == 'Digest': |
| return self.retry_http_digest_auth(req, authreq) |
| |
| def retry_http_digest_auth(self, req, auth): |
| token, challenge = string.split(auth, ' ', 1) |
| chal = parse_keqv_list(parse_http_list(challenge)) |
| auth = self.get_authorization(req, chal) |
| if auth: |
| req.add_header('Authorization', 'Digest %s' % auth) |
| resp = self.parent.open(req) |
| self.__current_realm = None |
| return resp |
| |
| def get_authorization(self, req, chal): |
| try: |
| realm = chal['realm'] |
| nonce = chal['nonce'] |
| algorithm = chal.get('algorithm', 'MD5') |
| # mod_digest doesn't send an opaque, even though it isn't |
| # supposed to be optional |
| opaque = chal.get('opaque', None) |
| except KeyError: |
| return None |
| |
| if self.__current_realm is None: |
| self.__current_realm = realm |
| else: |
| self.__current_realm = realm |
| return None |
| |
| H, KD = self.get_algorithm_impls(algorithm) |
| if H is None: |
| return None |
| |
| user, pw = self.passwd.find_user_password(realm, |
| req.get_full_url()) |
| if user is None: |
| return None |
| |
| # XXX not implemented yet |
| if req.has_data(): |
| entdig = self.get_entity_digest(req.get_data(), chal) |
| else: |
| entdig = None |
| |
| A1 = "%s:%s:%s" % (user, realm, pw) |
| A2 = "%s:%s" % (req.has_data() and 'POST' or 'GET', |
| # XXX selector: what about proxies and full urls |
| req.get_selector()) |
| respdig = KD(H(A1), "%s:%s" % (nonce, H(A2))) |
| # XXX should the partial digests be encoded too? |
| |
| base = 'username="%s", realm="%s", nonce="%s", uri="%s", ' \ |
| 'response="%s"' % (user, realm, nonce, req.get_selector(), |
| respdig) |
| if opaque: |
| base = base + ', opaque="%s"' % opaque |
| if entdig: |
| base = base + ', digest="%s"' % entdig |
| if algorithm != 'MD5': |
| base = base + ', algorithm="%s"' % algorithm |
| return base |
| |
| def get_algorithm_impls(self, algorithm): |
| # lambdas assume digest modules are imported at the top level |
| if algorithm == 'MD5': |
| H = lambda x, e=encode_digest:e(md5.new(x).digest()) |
| elif algorithm == 'SHA': |
| H = lambda x, e=encode_digest:e(sha.new(x).digest()) |
| # XXX MD5-sess |
| KD = lambda s, d, H=H: H("%s:%s" % (s, d)) |
| return H, KD |
| |
| def get_entity_digest(self, data, chal): |
| # XXX not implemented yet |
| return None |
| |
| def encode_digest(digest): |
| hexrep = [] |
| for c in digest: |
| n = (ord(c) >> 4) & 0xf |
| hexrep.append(hex(n)[-1]) |
| n = ord(c) & 0xf |
| hexrep.append(hex(n)[-1]) |
| return string.join(hexrep, '') |
| |
| |
| class HTTPHandler(BaseHandler): |
| def http_open(self, req): |
| # XXX devise a new mechanism to specify user/password |
| host = req.get_host() |
| if not host: |
| raise URLError('no host given') |
| |
| try: |
| h = httplib.HTTP(host) # will parse host:port |
| if req.has_data(): |
| data = req.get_data() |
| h.putrequest('POST', req.get_selector()) |
| h.putheader('Content-type', |
| 'application/x-www-form-urlencoded') |
| h.putheader('Content-length', '%d' % len(data)) |
| else: |
| h.putrequest('GET', req.get_selector()) |
| except socket.error, err: |
| raise URLError(err) |
| |
| # XXX proxies would have different host here |
| h.putheader('Host', host) |
| for args in self.parent.addheaders: |
| h.putheader(*args) |
| for k, v in req.headers.items(): |
| h.putheader(k, v) |
| h.endheaders() |
| if req.has_data(): |
| h.send(data + '\r\n') |
| |
| code, msg, hdrs = h.getreply() |
| fp = h.getfile() |
| if code == 200: |
| return addinfourl(fp, hdrs, req.get_full_url()) |
| else: |
| return self.parent.error('http', req, fp, code, msg, hdrs) |
| |
| class UnknownHandler(BaseHandler): |
| def unknown_open(self, req): |
| type = req.get_type() |
| raise URLError('unknown url type: %s' % type) |
| |
| def parse_keqv_list(l): |
| """Parse list of key=value strings where keys are not duplicated.""" |
| parsed = {} |
| for elt in l: |
| k, v = string.split(elt, '=', 1) |
| if v[0] == '"' and v[-1] == '"': |
| v = v[1:-1] |
| parsed[k] = v |
| return parsed |
| |
| def parse_http_list(s): |
| """Parse lists as described by RFC 2068 Section 2. |
| |
| In particular, parse comman-separated lists where the elements of |
| the list may include quoted-strings. A quoted-string could |
| contain a comma. |
| """ |
| # XXX this function could probably use more testing |
| |
| list = [] |
| end = len(s) |
| i = 0 |
| inquote = 0 |
| start = 0 |
| while i < end: |
| cur = s[i:] |
| c = string.find(cur, ',') |
| q = string.find(cur, '"') |
| if c == -1: |
| list.append(s[start:]) |
| break |
| if q == -1: |
| if inquote: |
| raise ValueError, "unbalanced quotes" |
| else: |
| list.append(s[start:i+c]) |
| i = i + c + 1 |
| continue |
| if inquote: |
| if q < c: |
| list.append(s[start:i+c]) |
| i = i + c + 1 |
| start = i |
| inquote = 0 |
| else: |
| i = i + q |
| else: |
| if c < q: |
| list.append(s[start:i+c]) |
| i = i + c + 1 |
| start = i |
| else: |
| inquote = 1 |
| i = i + q + 1 |
| return map(string.strip, list) |
| |
| class FileHandler(BaseHandler): |
| # Use local file or FTP depending on form of URL |
| def file_open(self, req): |
| url = req.get_selector() |
| if url[:2] == '//' and url[2:3] != '/': |
| req.type = 'ftp' |
| return self.parent.open(req) |
| else: |
| return self.open_local_file(req) |
| |
| # names for the localhost |
| names = None |
| def get_names(self): |
| if FileHandler.names is None: |
| FileHandler.names = (socket.gethostbyname('localhost'), |
| socket.gethostbyname(socket.gethostname())) |
| return FileHandler.names |
| |
| # not entirely sure what the rules are here |
| def open_local_file(self, req): |
| mtype = mimetypes.guess_type(req.get_selector())[0] |
| headers = mimetools.Message(StringIO('Content-Type: %s\n' \ |
| % (mtype or 'text/plain'))) |
| host = req.get_host() |
| file = req.get_selector() |
| if host: |
| host, port = splitport(host) |
| if not host or \ |
| (not port and socket.gethostbyname(host) in self.get_names()): |
| return addinfourl(open(url2pathname(file), 'rb'), |
| headers, 'file:'+file) |
| raise URLError('file not on local host') |
| |
| class FTPHandler(BaseHandler): |
| def ftp_open(self, req): |
| host = req.get_host() |
| if not host: |
| raise IOError, ('ftp error', 'no host given') |
| # XXX handle custom username & password |
| try: |
| host = socket.gethostbyname(host) |
| except socket.error, msg: |
| raise URLError(msg) |
| host, port = splitport(host) |
| if port is None: |
| port = ftplib.FTP_PORT |
| path, attrs = splitattr(req.get_selector()) |
| path = unquote(path) |
| dirs = string.splitfields(path, '/') |
| dirs, file = dirs[:-1], dirs[-1] |
| if dirs and not dirs[0]: |
| dirs = dirs[1:] |
| user = passwd = '' # XXX |
| try: |
| fw = self.connect_ftp(user, passwd, host, port, dirs) |
| type = file and 'I' or 'D' |
| for attr in attrs: |
| attr, value = splitattr(attr) |
| if string.lower(attr) == 'type' and \ |
| value in ('a', 'A', 'i', 'I', 'd', 'D'): |
| type = string.upper(value) |
| fp, retrlen = fw.retrfile(file, type) |
| if retrlen is not None and retrlen >= 0: |
| sf = StringIO('Content-Length: %d\n' % retrlen) |
| headers = mimetools.Message(sf) |
| else: |
| headers = noheaders() |
| return addinfourl(fp, headers, req.get_full_url()) |
| except ftplib.all_errors, msg: |
| raise IOError, ('ftp error', msg), sys.exc_info()[2] |
| |
| def connect_ftp(self, user, passwd, host, port, dirs): |
| fw = ftpwrapper(user, passwd, host, port, dirs) |
| ## fw.ftp.set_debuglevel(1) |
| return fw |
| |
| class CacheFTPHandler(FTPHandler): |
| # XXX would be nice to have pluggable cache strategies |
| # XXX this stuff is definitely not thread safe |
| def __init__(self): |
| self.cache = {} |
| self.timeout = {} |
| self.soonest = 0 |
| self.delay = 60 |
| self.max_conns = 16 |
| |
| def setTimeout(self, t): |
| self.delay = t |
| |
| def setMaxConns(self, m): |
| self.max_conns = m |
| |
| def connect_ftp(self, user, passwd, host, port, dirs): |
| key = user, passwd, host, port |
| if self.cache.has_key(key): |
| self.timeout[key] = time.time() + self.delay |
| else: |
| self.cache[key] = ftpwrapper(user, passwd, host, port, dirs) |
| self.timeout[key] = time.time() + self.delay |
| self.check_cache() |
| return self.cache[key] |
| |
| def check_cache(self): |
| # first check for old ones |
| t = time.time() |
| if self.soonest <= t: |
| for k, v in self.timeout.items(): |
| if v < t: |
| self.cache[k].close() |
| del self.cache[k] |
| del self.timeout[k] |
| self.soonest = min(self.timeout.values()) |
| |
| # then check the size |
| if len(self.cache) == self.max_conns: |
| for k, v in self.timeout.items(): |
| if v == self.soonest: |
| del self.cache[k] |
| del self.timeout[k] |
| break |
| self.soonest = min(self.timeout.values()) |
| |
| class GopherHandler(BaseHandler): |
| def gopher_open(self, req): |
| host = req.get_host() |
| if not host: |
| raise GopherError('no host given') |
| host = unquote(host) |
| selector = req.get_selector() |
| type, selector = splitgophertype(selector) |
| selector, query = splitquery(selector) |
| selector = unquote(selector) |
| if query: |
| query = unquote(query) |
| fp = gopherlib.send_query(selector, query, host) |
| else: |
| fp = gopherlib.send_selector(selector, host) |
| return addinfourl(fp, noheaders(), req.get_full_url()) |
| |
| #bleck! don't use this yet |
| class OpenerFactory: |
| |
| default_handlers = [UnknownHandler, HTTPHandler, |
| HTTPDefaultErrorHandler, HTTPRedirectHandler, |
| FTPHandler, FileHandler] |
| proxy_handlers = [ProxyHandler] |
| handlers = [] |
| replacement_handlers = [] |
| |
| def add_proxy_handler(self, ph): |
| self.proxy_handlers = self.proxy_handlers + [ph] |
| |
| def add_handler(self, h): |
| self.handlers = self.handlers + [h] |
| |
| def replace_handler(self, h): |
| pass |
| |
| def build_opener(self): |
| opener = OpenerDirectory() |
| for ph in self.proxy_handlers: |
| if type(ph) == types.ClassType: |
| ph = ph() |
| opener.add_handler(ph) |
| |
| if __name__ == "__main__": |
| # XXX some of the test code depends on machine configurations that |
| # are internal to CNRI. Need to set up a public server with the |
| # right authentication configuration for test purposes. |
| if socket.gethostname() == 'bitdiddle': |
| localhost = 'bitdiddle.cnri.reston.va.us' |
| elif socket.gethostname() == 'bitdiddle.concentric.net': |
| localhost = 'localhost' |
| else: |
| localhost = None |
| urls = [ |
| # Thanks to Fred for finding these! |
| 'gopher://gopher.lib.ncsu.edu/11/library/stacks/Alex', |
| 'gopher://gopher.vt.edu:10010/10/33', |
| |
| 'file:/etc/passwd', |
| 'file://nonsensename/etc/passwd', |
| 'ftp://www.python.org/pub/tmp/httplib.py', |
| 'ftp://www.python.org/pub/tmp/imageop.c', |
| 'ftp://www.python.org/pub/tmp/blat', |
| 'http://www.espn.com/', # redirect |
| 'http://www.python.org/Spanish/Inquistion/', |
| ('http://grail.cnri.reston.va.us/cgi-bin/faqw.py', |
| 'query=pythonistas&querytype=simple&casefold=yes&req=search'), |
| 'http://www.python.org/', |
| 'ftp://prep.ai.mit.edu/welcome.msg', |
| 'ftp://www.python.org/pub/tmp/figure.prn', |
| 'ftp://www.python.org/pub/tmp/interp.pl', |
| 'http://checkproxy.cnri.reston.va.us/test/test.html', |
| ] |
| |
| if localhost is not None: |
| urls = urls + [ |
| 'file://%s/etc/passwd' % localhost, |
| 'http://%s/simple/' % localhost, |
| 'http://%s/digest/' % localhost, |
| 'http://%s/not/found.h' % localhost, |
| ] |
| |
| bauth = HTTPBasicAuthHandler() |
| bauth.add_password('basic_test_realm', localhost, 'jhylton', |
| 'password') |
| dauth = HTTPDigestAuthHandler() |
| dauth.add_password('digest_test_realm', localhost, 'jhylton', |
| 'password') |
| |
| |
| cfh = CacheFTPHandler() |
| cfh.setTimeout(1) |
| |
| # XXX try out some custom proxy objects too! |
| def at_cnri(req): |
| host = req.get_host() |
| print host |
| if host[-18:] == '.cnri.reston.va.us': |
| return 1 |
| p = CustomProxy('http', at_cnri, 'proxy.cnri.reston.va.us') |
| ph = CustomProxyHandler(p) |
| |
| install_opener(build_opener(dauth, bauth, cfh, GopherHandler, ph)) |
| |
| for url in urls: |
| if type(url) == types.TupleType: |
| url, req = url |
| else: |
| req = None |
| print url |
| try: |
| f = urlopen(url, req) |
| except IOError, err: |
| print "IOError:", err |
| except socket.error, err: |
| print "socket.error:", err |
| else: |
| buf = f.read() |
| f.close() |
| print "read %d bytes" % len(buf) |
| print |
| time.sleep(0.1) |