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request.py99.1 KB · 2777 lines
"""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 (describedbelow).  It opens the URL and returns the results as file-likeobject; the returned object has some extra methods described below. The OpenerDirector manages a collection of Handler objects that doall the actual work.  Each Handler implements a particular protocol oroption.  The OpenerDirector is a composite object that invokes theHandlers needed to open the requested URL.  For example, theHTTPHandler performs HTTP GET and POST requests and deals withnon-error returns.  The HTTPRedirectHandler automatically deals withHTTP 301, 302, 303 and 307 redirect errors, and the HTTPDigestAuthHandlerdeals with digest authentication. urlopen(url, data=None) -- Basic usage is the same as originalurllib.  pass the url and optionally data to post to an HTTP URL, andget a file-like object back.  One difference is that you can also passa Request instance instead of URL.  Raises a URLError (subclass ofOSError); for HTTP errors, raises an HTTPError, which can also betreated as a valid response. build_opener -- Function that creates a new OpenerDirector instance.Will install the default handlers.  Accepts one or more Handlers asarguments, either instances or Handler classes that it willinstantiate.  If one of the argument is a subclass of the defaulthandler, the argument will be installed instead of the default. install_opener -- Installs a new opener as the default opener. objects of interest: OpenerDirector -- Sets up the User Agent as the Python-urllib client and managesthe Handler classes, while dealing with requests and responses. Request -- An object that encapsulates the state of a request.  Thestate can be as simple as the URL.  It can also include extra HTTPheaders, e.g. a User-Agent. BaseHandler -- internals:BaseHandler and parent_call_chain conventions Example usage: import urllib.request # set up authentication infoauthinfo = urllib.request.HTTPBasicAuthHandler()authinfo.add_password(realm='PDQ Application',                      uri='https://mahler:8092/site-updates.py',                      user='klem',                      passwd='geheim$parole') proxy_support = urllib.request.ProxyHandler({"http" : "http://ahad-haam:3128"}) # build a new opener that adds authentication and caching FTP handlersopener = urllib.request.build_opener(proxy_support, authinfo,                                     urllib.request.CacheFTPHandler) # install iturllib.request.install_opener(opener) f = urllib.request.urlopen('https://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.# ftp errors aren't handled cleanly# check digest against correct (i.e. non-apache) implementation # Possible extensions:# complex proxies  XXX not sure what exactly was meant by this# abstract factory for opener import base64import bisectimport emailimport hashlibimport http.clientimport ioimport osimport posixpathimport reimport socketimport stringimport sysimport timeimport tempfileimport contextlibimport warnings  from urllib.error import URLError, HTTPError, ContentTooShortErrorfrom urllib.parse import (    urlparse, urlsplit, urljoin, unwrap, quote, unquote,    _splittype, _splithost, _splitport, _splituser, _splitpasswd,    _splitattr, _splitquery, _splitvalue, _splittag, _to_bytes,    unquote_to_bytes, urlunparse)from urllib.response import addinfourl, addclosehook # check for SSLtry:    import sslexcept ImportError:    _have_ssl = Falseelse:    _have_ssl = True __all__ = [    # Classes    'Request', 'OpenerDirector', 'BaseHandler', 'HTTPDefaultErrorHandler',    'HTTPRedirectHandler', 'HTTPCookieProcessor', 'ProxyHandler',    'HTTPPasswordMgr', 'HTTPPasswordMgrWithDefaultRealm',    'HTTPPasswordMgrWithPriorAuth', 'AbstractBasicAuthHandler',    'HTTPBasicAuthHandler', 'ProxyBasicAuthHandler', 'AbstractDigestAuthHandler',    'HTTPDigestAuthHandler', 'ProxyDigestAuthHandler', 'HTTPHandler',    'FileHandler', 'FTPHandler', 'CacheFTPHandler', 'DataHandler',    'UnknownHandler', 'HTTPErrorProcessor',    # Functions    'urlopen', 'install_opener', 'build_opener',    'pathname2url', 'url2pathname', 'getproxies',    # Legacy interface    'urlretrieve', 'urlcleanup', 'URLopener', 'FancyURLopener',] # used in User-Agent header sent__version__ = '%d.%d' % sys.version_info[:2] _opener = Nonedef urlopen(url, data=None, timeout=socket._GLOBAL_DEFAULT_TIMEOUT,            *, cafile=None, capath=None, cadefault=False, context=None):    '''Open the URL url, which can be either a string or a Request object.     *data* must be an object specifying additional data to be sent to    the server, or None if no such data is needed.  See Request for    details.     urllib.request module uses HTTP/1.1 and includes a "Connection:close"    header in its HTTP requests.     The optional *timeout* parameter specifies a timeout in seconds for    blocking operations like the connection attempt (if not specified, the    global default timeout setting will be used). This only works for HTTP,    HTTPS and FTP connections.     If *context* is specified, it must be a ssl.SSLContext instance describing    the various SSL options. See HTTPSConnection for more details.     The optional *cafile* and *capath* parameters specify a set of trusted CA    certificates for HTTPS requests. cafile should point to a single file    containing a bundle of CA certificates, whereas capath should point to a    directory of hashed certificate files. More information can be found in    ssl.SSLContext.load_verify_locations().     The *cadefault* parameter is ignored.      This function always returns an object which can work as a    context manager and has the properties url, headers, and status.    See urllib.response.addinfourl for more detail on these properties.     For HTTP and HTTPS URLs, this function returns a http.client.HTTPResponse    object slightly modified. In addition to the three new methods above, the    msg attribute contains the same information as the reason attribute ---    the reason phrase returned by the server --- instead of the response    headers as it is specified in the documentation for HTTPResponse.     For FTP, file, and data URLs and requests explicitly handled by legacy    URLopener and FancyURLopener classes, this function returns a    urllib.response.addinfourl object.     Note that None may be returned if no handler handles the request (though    the default installed global OpenerDirector uses UnknownHandler to ensure    this never happens).     In addition, if proxy settings are detected (for example, when a *_proxy    environment variable like http_proxy is set), ProxyHandler is default    installed and makes sure the requests are handled through the proxy.     '''    global _opener    if cafile or capath or cadefault:        import warnings        warnings.warn("cafile, capath and cadefault are deprecated, use a "                      "custom context instead.", DeprecationWarning, 2)        if context is not None:            raise ValueError(                "You can't pass both context and any of cafile, capath, and "                "cadefault"            )        if not _have_ssl:            raise ValueError('SSL support not available')        context = ssl.create_default_context(ssl.Purpose.SERVER_AUTH,                                             cafile=cafile,                                             capath=capath)        https_handler = HTTPSHandler(context=context)        opener = build_opener(https_handler)    elif context:        https_handler = HTTPSHandler(context=context)        opener = build_opener(https_handler)    elif _opener is None:        _opener = opener = build_opener()    else:        opener = _opener    return opener.open(url, data, timeout) def install_opener(opener):    global _opener    _opener = opener _url_tempfiles = []def urlretrieve(url, filename=None, reporthook=None, data=None):    """    Retrieve a URL into a temporary location on disk.     Requires a URL argument. If a filename is passed, it is used as    the temporary file location. The reporthook argument should be    a callable that accepts a block number, a read size, and the    total file size of the URL target. The data argument should be    valid URL encoded data.     If a filename is passed and the URL points to a local resource,    the result is a copy from local file to new file.     Returns a tuple containing the path to the newly created    data file as well as the resulting HTTPMessage object.    """    url_type, path = _splittype(url)     with contextlib.closing(urlopen(url, data)) as fp:        headers = fp.info()         # Just return the local path and the "headers" for file://        # URLs. No sense in performing a copy unless requested.        if url_type == "file" and not filename:            return os.path.normpath(path), headers         # Handle temporary file setup.        if filename:            tfp = open(filename, 'wb')        else:            tfp = tempfile.NamedTemporaryFile(delete=False)            filename = tfp.name            _url_tempfiles.append(filename)         with tfp:            result = filename, headers            bs = 1024*8            size = -1            read = 0            blocknum = 0            if "content-length" in headers:                size = int(headers["Content-Length"])             if reporthook:                reporthook(blocknum, bs, size)             while True:                block = fp.read(bs)                if not block:                    break                read += len(block)                tfp.write(block)                blocknum += 1                if reporthook:                    reporthook(blocknum, bs, size)     if size >= 0 and read < size:        raise ContentTooShortError(            "retrieval incomplete: got only %i out of %i bytes"            % (read, size), result)     return result def urlcleanup():    """Clean up temporary files from urlretrieve calls."""    for temp_file in _url_tempfiles:        try:            os.unlink(temp_file)        except OSError:            pass     del _url_tempfiles[:]    global _opener    if _opener:        _opener = None # copied from cookielib.py_cut_port_re = re.compile(r":\d+$", re.ASCII)def request_host(request):    """Return request-host, as defined by RFC 2965.     Variation from RFC: returned value is lowercased, for convenient    comparison.     """    url = request.full_url    host = urlparse(url)[1]    if host == "":        host = request.get_header("Host", "")     # remove port, if present    host = _cut_port_re.sub("", host, 1)    return host.lower() class Request:     def __init__(self, url, data=None, headers={},                 origin_req_host=None, unverifiable=False,                 method=None):        self.full_url = url        self.headers = {}        self.unredirected_hdrs = {}        self._data = None        self.data = data        self._tunnel_host = None        for key, value in headers.items():            self.add_header(key, value)        if origin_req_host is None:            origin_req_host = request_host(self)        self.origin_req_host = origin_req_host        self.unverifiable = unverifiable        if method:            self.method = method     @property    def full_url(self):        if self.fragment:            return '{}#{}'.format(self._full_url, self.fragment)        return self._full_url     @full_url.setter    def full_url(self, url):        # unwrap('<URL:type://host/path>') --> 'type://host/path'        self._full_url = unwrap(url)        self._full_url, self.fragment = _splittag(self._full_url)        self._parse()     @full_url.deleter    def full_url(self):        self._full_url = None        self.fragment = None        self.selector = ''     @property    def data(self):        return self._data     @data.setter    def data(self, data):        if data != self._data:            self._data = data            # issue 16464            # if we change data we need to remove content-length header            # (cause it's most probably calculated for previous value)            if self.has_header("Content-length"):                self.remove_header("Content-length")     @data.deleter    def data(self):        self.data = None     def _parse(self):        self.type, rest = _splittype(self._full_url)        if self.type is None:            raise ValueError("unknown url type: %r" % self.full_url)        self.host, self.selector = _splithost(rest)        if self.host:            self.host = unquote(self.host)     def get_method(self):        """Return a string indicating the HTTP request method."""        default_method = "POST" if self.data is not None else "GET"        return getattr(self, 'method', default_method)     def get_full_url(self):        return self.full_url     def set_proxy(self, host, type):        if self.type == 'https' and not self._tunnel_host:            self._tunnel_host = self.host        else:            self.type= type            self.selector = self.full_url        self.host = host     def has_proxy(self):        return self.selector == self.full_url     def add_header(self, key, val):        # useful for something like authentication        self.headers[key.capitalize()] = val     def add_unredirected_header(self, key, val):        # will not be added to a redirected request        self.unredirected_hdrs[key.capitalize()] = val     def has_header(self, header_name):        return (header_name in self.headers or                header_name in self.unredirected_hdrs)     def get_header(self, header_name, default=None):        return self.headers.get(            header_name,            self.unredirected_hdrs.get(header_name, default))     def remove_header(self, header_name):        self.headers.pop(header_name, None)        self.unredirected_hdrs.pop(header_name, None)     def header_items(self):        hdrs = {**self.unredirected_hdrs, **self.headers}        return list(hdrs.items()) class OpenerDirector:    def __init__(self):        client_version = "Python-urllib/%s" % __version__        self.addheaders = [('User-agent', client_version)]        # self.handlers is retained only for backward compatibility        self.handlers = []        # manage the individual handlers        self.handle_open = {}        self.handle_error = {}        self.process_response = {}        self.process_request = {}     def add_handler(self, handler):        if not hasattr(handler, "add_parent"):            raise TypeError("expected BaseHandler instance, got %r" %                            type(handler))         added = False        for meth in dir(handler):            if meth in ["redirect_request", "do_open", "proxy_open"]:                # oops, coincidental match                continue             i = meth.find("_")            protocol = meth[:i]            condition = meth[i+1:]             if condition.startswith("error"):                j = condition.find("_") + i + 1                kind = meth[j+1:]                try:                    kind = int(kind)                except ValueError:                    pass                lookup = self.handle_error.get(protocol, {})                self.handle_error[protocol] = lookup            elif condition == "open":                kind = protocol                lookup = self.handle_open            elif condition == "response":                kind = protocol                lookup = self.process_response            elif condition == "request":                kind = protocol                lookup = self.process_request            else:                continue             handlers = lookup.setdefault(kind, [])            if handlers:                bisect.insort(handlers, handler)            else:                handlers.append(handler)            added = True         if added:            bisect.insort(self.handlers, handler)            handler.add_parent(self)     def close(self):        # Only exists for backwards compatibility.        pass     def _call_chain(self, chain, kind, meth_name, *args):        # Handlers raise an exception if no one else should try to handle        # the request, or return None if they can't but another handler        # could.  Otherwise, they return the response.        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, timeout=socket._GLOBAL_DEFAULT_TIMEOUT):        # accept a URL or a Request object        if isinstance(fullurl, str):            req = Request(fullurl, data)        else:            req = fullurl            if data is not None:                req.data = data         req.timeout = timeout        protocol = req.type         # pre-process request        meth_name = protocol+"_request"        for processor in self.process_request.get(protocol, []):            meth = getattr(processor, meth_name)            req = meth(req)         sys.audit('urllib.Request', req.full_url, req.data, req.headers, req.get_method())        response = self._open(req, data)         # post-process response        meth_name = protocol+"_response"        for processor in self.process_response.get(protocol, []):            meth = getattr(processor, meth_name)            response = meth(req, response)         return response     def _open(self, req, data=None):        result = self._call_chain(self.handle_open, 'default',                                  'default_open', req)        if result:            return result         protocol = req.type        result = self._call_chain(self.handle_open, protocol, protocol +                                  '_open', req)        if result:            return result         return self._call_chain(self.handle_open, 'unknown',                                'unknown_open', req)     def error(self, proto, *args):        if proto in ('http', 'https'):            # XXX http[s] protocols are special-cased            dict = self.handle_error['http'] # https is not different than http            proto = args[2]  # YUCK!            meth_name = 'http_error_%s' % 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) # XXX probably also want an abstract factory that knows 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, FTP and when applicable HTTPS.     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, HTTPErrorProcessor,                       DataHandler]    if hasattr(http.client, "HTTPSConnection"):        default_classes.append(HTTPSHandler)    skip = set()    for klass in default_classes:        for check in handlers:            if isinstance(check, type):                if issubclass(check, klass):                    skip.add(klass)            elif isinstance(check, klass):                skip.add(klass)    for klass in skip:        default_classes.remove(klass)     for klass in default_classes:        opener.add_handler(klass())     for h in handlers:        if isinstance(h, type):            h = h()        opener.add_handler(h)    return opener class BaseHandler:    handler_order = 500     def add_parent(self, parent):        self.parent = parent     def close(self):        # Only exists for backwards compatibility        pass     def __lt__(self, other):        if not hasattr(other, "handler_order"):            # Try to preserve the old behavior of having custom classes            # inserted after default ones (works only for custom user            # classes which are not aware of handler_order).            return True        return self.handler_order < other.handler_order  class HTTPErrorProcessor(BaseHandler):    """Process HTTP error responses."""    handler_order = 1000  # after all other processing     def http_response(self, request, response):        code, msg, hdrs = response.code, response.msg, response.info()         # According to RFC 2616, "2xx" code indicates that the client's        # request was successfully received, understood, and accepted.        if not (200 <= code < 300):            response = self.parent.error(                'http', request, response, code, msg, hdrs)         return response     https_response = http_response class HTTPDefaultErrorHandler(BaseHandler):    def http_error_default(self, req, fp, code, msg, hdrs):        raise HTTPError(req.full_url, code, msg, hdrs, fp) class HTTPRedirectHandler(BaseHandler):    # maximum number of redirections to any single URL    # this is needed because of the state that cookies introduce    max_repeats = 4    # maximum total number of redirections (regardless of URL) before    # assuming we're in a loop    max_redirections = 10     def redirect_request(self, req, fp, code, msg, headers, newurl):        """Return a Request or None in response to a redirect.         This is called by the http_error_30x methods when a        redirection response is received.  If a redirection should        take place, return a new Request to allow http_error_30x to        perform the redirect.  Otherwise, raise HTTPError if no-one        else should try to handle this url.  Return None if you can't        but another Handler might.        """        m = req.get_method()        if (not (code in (301, 302, 303, 307) and m in ("GET", "HEAD")            or code in (301, 302, 303) and m == "POST")):            raise HTTPError(req.full_url, code, msg, headers, fp)         # Strictly (according to RFC 2616), 301 or 302 in response to        # a POST MUST NOT cause a redirection without confirmation        # from the user (of urllib.request, in this case).  In practice,        # essentially all clients do redirect in this case, so we do        # the same.         # Be conciliant with URIs containing a space.  This is mainly        # redundant with the more complete encoding done in http_error_302(),        # but it is kept for compatibility with other callers.        newurl = newurl.replace(' ', '%20')         CONTENT_HEADERS = ("content-length", "content-type")        newheaders = {k: v for k, v in req.headers.items()                      if k.lower() not in CONTENT_HEADERS}        return Request(newurl,                       headers=newheaders,                       origin_req_host=req.origin_req_host,                       unverifiable=True)     # 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):        # Some servers (incorrectly) return multiple Location headers        # (so probably same goes for URI).  Use first header.        if "location" in headers:            newurl = headers["location"]        elif "uri" in headers:            newurl = headers["uri"]        else:            return         # fix a possible malformed URL        urlparts = urlparse(newurl)         # For security reasons we don't allow redirection to anything other        # than http, https or ftp.         if urlparts.scheme not in ('http', 'https', 'ftp', ''):            raise HTTPError(                newurl, code,                "%s - Redirection to url '%s' is not allowed" % (msg, newurl),                headers, fp)         if not urlparts.path and urlparts.netloc:            urlparts = list(urlparts)            urlparts[2] = "/"        newurl = urlunparse(urlparts)         # http.client.parse_headers() decodes as ISO-8859-1.  Recover the        # original bytes and percent-encode non-ASCII bytes, and any special        # characters such as the space.        newurl = quote(            newurl, encoding="iso-8859-1", safe=string.punctuation)        newurl = urljoin(req.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 = self.redirect_request(req, fp, code, msg, headers, newurl)        if new is None:            return         # loop detection        # .redirect_dict has a key url if url was previously visited.        if hasattr(req, 'redirect_dict'):            visited = new.redirect_dict = req.redirect_dict            if (visited.get(newurl, 0) >= self.max_repeats or                len(visited) >= self.max_redirections):                raise HTTPError(req.full_url, code,                                self.inf_msg + msg, headers, fp)        else:            visited = new.redirect_dict = req.redirect_dict = {}        visited[newurl] = visited.get(newurl, 0) + 1         # Don't close the fp until we are sure that we won't use it        # with HTTPError.        fp.read()        fp.close()         return self.parent.open(new, timeout=req.timeout)     http_error_301 = http_error_303 = http_error_307 = http_error_302     inf_msg = "The HTTP server returned a redirect error that would " \              "lead to an infinite loop.\n" \              "The last 30x error message was:\n"  def _parse_proxy(proxy):    """Return (scheme, user, password, host/port) given a URL or an authority.     If a URL is supplied, it must have an authority (host:port) component.    According to RFC 3986, having an authority component means the URL must    have two slashes after the scheme.    """    scheme, r_scheme = _splittype(proxy)    if not r_scheme.startswith("/"):        # authority        scheme = None        authority = proxy    else:        # URL        if not r_scheme.startswith("//"):            raise ValueError("proxy URL with no authority: %r" % proxy)        # We have an authority, so for RFC 3986-compliant URLs (by ss 3.        # and 3.3.), path is empty or starts with '/'        if '@' in r_scheme:            host_separator = r_scheme.find('@')            end = r_scheme.find("/", host_separator)        else:            end = r_scheme.find("/", 2)        if end == -1:            end = None        authority = r_scheme[2:end]    userinfo, hostport = _splituser(authority)    if userinfo is not None:        user, password = _splitpasswd(userinfo)    else:        user = password = None    return scheme, user, password, hostport class ProxyHandler(BaseHandler):    # Proxies must be in front    handler_order = 100     def __init__(self, proxies=None):        if proxies is None:            proxies = getproxies()        assert hasattr(proxies, 'keys'), "proxies must be a mapping"        self.proxies = proxies        for type, url in proxies.items():            type = type.lower()            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.type        proxy_type, user, password, hostport = _parse_proxy(proxy)        if proxy_type is None:            proxy_type = orig_type         if req.host and proxy_bypass(req.host):            return None         if user and password:            user_pass = '%s:%s' % (unquote(user),                                   unquote(password))            creds = base64.b64encode(user_pass.encode()).decode("ascii")            req.add_header('Proxy-authorization', 'Basic ' + creds)        hostport = unquote(hostport)        req.set_proxy(hostport, proxy_type)        if orig_type == proxy_type or orig_type == 'https':            # let other handlers take care of it            return None        else:            # need to start over, because the other handlers don't            # grok the proxy's URL type            # e.g. if we have a constructor arg proxies like so:            # {'http': 'ftp://proxy.example.com'}, we may end up turning            # a request for http://acme.example.com/a into one for            # ftp://proxy.example.com/a            return self.parent.open(req, timeout=req.timeout) 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 isinstance(uri, str):            uri = [uri]        if realm not in self.passwd:            self.passwd[realm] = {}        for default_port in True, False:            reduced_uri = tuple(                self.reduce_uri(u, default_port) for u in uri)            self.passwd[realm][reduced_uri] = (user, passwd)     def find_user_password(self, realm, authuri):        domains = self.passwd.get(realm, {})        for default_port in True, False:            reduced_authuri = self.reduce_uri(authuri, default_port)            for uris, authinfo in domains.items():                for uri in uris:                    if self.is_suburi(uri, reduced_authuri):                        return authinfo        return None, None     def reduce_uri(self, uri, default_port=True):        """Accept authority or URI and extract only the authority and path."""        # note HTTP URLs do not have a userinfo component        parts = urlsplit(uri)        if parts[1]:            # URI            scheme = parts[0]            authority = parts[1]            path = parts[2] or '/'        else:            # host or host:port            scheme = None            authority = uri            path = '/'        host, port = _splitport(authority)        if default_port and port is None and scheme is not None:            dport = {"http": 80,                     "https": 443,                     }.get(scheme)            if dport is not None:                authority = "%s:%d" % (host, dport)        return authority, path     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 True        if base[0] != test[0]:            return False        prefix = base[1]        if prefix[-1:] != '/':            prefix += '/'        return test[1].startswith(prefix)  class HTTPPasswordMgrWithDefaultRealm(HTTPPasswordMgr):     def find_user_password(self, realm, authuri):        user, password = HTTPPasswordMgr.find_user_password(self, realm,                                                            authuri)        if user is not None:            return user, password        return HTTPPasswordMgr.find_user_password(self, None, authuri)  class HTTPPasswordMgrWithPriorAuth(HTTPPasswordMgrWithDefaultRealm):     def __init__(self, *args, **kwargs):        self.authenticated = {}        super().__init__(*args, **kwargs)     def add_password(self, realm, uri, user, passwd, is_authenticated=False):        self.update_authenticated(uri, is_authenticated)        # Add a default for prior auth requests        if realm is not None:            super().add_password(None, uri, user, passwd)        super().add_password(realm, uri, user, passwd)     def update_authenticated(self, uri, is_authenticated=False):        # uri could be a single URI or a sequence        if isinstance(uri, str):            uri = [uri]         for default_port in True, False:            for u in uri:                reduced_uri = self.reduce_uri(u, default_port)                self.authenticated[reduced_uri] = is_authenticated     def is_authenticated(self, authuri):        for default_port in True, False:            reduced_authuri = self.reduce_uri(authuri, default_port)            for uri in self.authenticated:                if self.is_suburi(uri, reduced_authuri):                    return self.authenticated[uri]  class AbstractBasicAuthHandler:     # XXX this allows for multiple auth-schemes, but will stupidly pick    # the last one with a realm specified.     # allow for double- and single-quoted realm values    # (single quotes are a violation of the RFC, but appear in the wild)    rx = re.compile('(?:^|,)'   # start of the string or ','                    '[ \t]*'    # optional whitespaces                    '([^ \t,]+)' # scheme like "Basic"                    '[ \t]+'    # mandatory whitespaces                    # realm=xxx                    # realm='xxx'                    # realm="xxx"                    'realm=(["\']?)([^"\']*)\\2',                    re.I)     # XXX could pre-emptively send auth info already accepted (RFC 2617,    # end of section 2, and section 1.2 immediately after "credentials"    # production).     def __init__(self, password_mgr=None):        if password_mgr is None:            password_mgr = HTTPPasswordMgr()        self.passwd = password_mgr        self.add_password = self.passwd.add_password     def _parse_realm(self, header):        # parse WWW-Authenticate header: accept multiple challenges per header        found_challenge = False        for mo in AbstractBasicAuthHandler.rx.finditer(header):            scheme, quote, realm = mo.groups()            if quote not in ['"', "'"]:                warnings.warn("Basic Auth Realm was unquoted",                              UserWarning, 3)             yield (scheme, realm)             found_challenge = True         if not found_challenge:            if header:                scheme = header.split()[0]            else:                scheme = ''            yield (scheme, None)     def http_error_auth_reqed(self, authreq, host, req, headers):        # host may be an authority (without userinfo) or a URL with an        # authority        headers = headers.get_all(authreq)        if not headers:            # no header found            return         unsupported = None        for header in headers:            for scheme, realm in self._parse_realm(header):                if scheme.lower() != 'basic':                    unsupported = scheme                    continue                 if realm is not None:                    # Use the first matching Basic challenge.                    # Ignore following challenges even if they use the Basic                    # scheme.                    return self.retry_http_basic_auth(host, req, realm)         if unsupported is not None:            raise ValueError("AbstractBasicAuthHandler does not "                             "support the following scheme: %r"                             % (scheme,))     def retry_http_basic_auth(self, host, req, realm):        user, pw = self.passwd.find_user_password(realm, host)        if pw is not None:            raw = "%s:%s" % (user, pw)            auth = "Basic " + base64.b64encode(raw.encode()).decode("ascii")            if req.get_header(self.auth_header, None) == auth:                return None            req.add_unredirected_header(self.auth_header, auth)            return self.parent.open(req, timeout=req.timeout)        else:            return None     def http_request(self, req):        if (not hasattr(self.passwd, 'is_authenticated') or           not self.passwd.is_authenticated(req.full_url)):            return req         if not req.has_header('Authorization'):            user, passwd = self.passwd.find_user_password(None, req.full_url)            credentials = '{0}:{1}'.format(user, passwd).encode()            auth_str = base64.standard_b64encode(credentials).decode()            req.add_unredirected_header('Authorization',                                        'Basic {}'.format(auth_str.strip()))        return req     def http_response(self, req, response):        if hasattr(self.passwd, 'is_authenticated'):            if 200 <= response.code < 300:                self.passwd.update_authenticated(req.full_url, True)            else:                self.passwd.update_authenticated(req.full_url, False)        return response     https_request = http_request    https_response = http_response   class HTTPBasicAuthHandler(AbstractBasicAuthHandler, BaseHandler):     auth_header = 'Authorization'     def http_error_401(self, req, fp, code, msg, headers):        url = req.full_url        response = self.http_error_auth_reqed('www-authenticate',                                          url, req, headers)        return response  class ProxyBasicAuthHandler(AbstractBasicAuthHandler, BaseHandler):     auth_header = 'Proxy-authorization'     def http_error_407(self, req, fp, code, msg, headers):        # http_error_auth_reqed requires that there is no userinfo component in        # authority.  Assume there isn't one, since urllib.request does not (and        # should not, RFC 3986 s. 3.2.1) support requests for URLs containing        # userinfo.        authority = req.host        response = self.http_error_auth_reqed('proxy-authenticate',                                          authority, req, headers)        return response  # Return n random bytes._randombytes = os.urandom  class AbstractDigestAuthHandler:    # Digest authentication is specified in RFC 2617.     # XXX The client does not inspect the Authentication-Info header    # in a successful response.     # XXX It should be possible to test this implementation against    # a mock server that just generates a static set of challenges.     # XXX qop="auth-int" supports is shaky     def __init__(self, passwd=None):        if passwd is None:            passwd = HTTPPasswordMgr()        self.passwd = passwd        self.add_password = self.passwd.add_password        self.retried = 0        self.nonce_count = 0        self.last_nonce = None     def reset_retry_count(self):        self.retried = 0     def http_error_auth_reqed(self, auth_header, host, req, headers):        authreq = headers.get(auth_header, None)        if self.retried > 5:            # Don't fail endlessly - if we failed once, we'll probably            # fail a second time. Hm. Unless the Password Manager is            # prompting for the information. Crap. This isn't great            # but it's better than the current 'repeat until recursion            # depth exceeded' approach <wink>            raise HTTPError(req.full_url, 401, "digest auth failed",                            headers, None)        else:            self.retried += 1        if authreq:            scheme = authreq.split()[0]            if scheme.lower() == 'digest':                return self.retry_http_digest_auth(req, authreq)            elif scheme.lower() != 'basic':                raise ValueError("AbstractDigestAuthHandler does not support"                                 " the following scheme: '%s'" % scheme)     def retry_http_digest_auth(self, req, auth):        token, challenge = auth.split(' ', 1)        chal = parse_keqv_list(filter(None, parse_http_list(challenge)))        auth = self.get_authorization(req, chal)        if auth:            auth_val = 'Digest %s' % auth            if req.headers.get(self.auth_header, None) == auth_val:                return None            req.add_unredirected_header(self.auth_header, auth_val)            resp = self.parent.open(req, timeout=req.timeout)            return resp     def get_cnonce(self, nonce):        # The cnonce-value is an opaque        # quoted string value provided by the client and used by both client        # and server to avoid chosen plaintext attacks, to provide mutual        # authentication, and to provide some message integrity protection.        # This isn't a fabulous effort, but it's probably Good Enough.        s = "%s:%s:%s:" % (self.nonce_count, nonce, time.ctime())        b = s.encode("ascii") + _randombytes(8)        dig = hashlib.sha1(b).hexdigest()        return dig[:16]     def get_authorization(self, req, chal):        try:            realm = chal['realm']            nonce = chal['nonce']            qop = chal.get('qop')            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         H, KD = self.get_algorithm_impls(algorithm)        if H is None:            return None         user, pw = self.passwd.find_user_password(realm, req.full_url)        if user is None:            return None         # XXX not implemented yet        if req.data is not None:            entdig = self.get_entity_digest(req.data, chal)        else:            entdig = None         A1 = "%s:%s:%s" % (user, realm, pw)        A2 = "%s:%s" % (req.get_method(),                        # XXX selector: what about proxies and full urls                        req.selector)        # NOTE: As per  RFC 2617, when server sends "auth,auth-int", the client could use either `auth`        #     or `auth-int` to the response back. we use `auth` to send the response back.        if qop is None:            respdig = KD(H(A1), "%s:%s" % (nonce, H(A2)))        elif 'auth' in qop.split(','):            if nonce == self.last_nonce:                self.nonce_count += 1            else:                self.nonce_count = 1                self.last_nonce = nonce            ncvalue = '%08x' % self.nonce_count            cnonce = self.get_cnonce(nonce)            noncebit = "%s:%s:%s:%s:%s" % (nonce, ncvalue, cnonce, 'auth', H(A2))            respdig = KD(H(A1), noncebit)        else:            # XXX handle auth-int.            raise URLError("qop '%s' is not supported." % qop)         # XXX should the partial digests be encoded too?         base = 'username="%s", realm="%s", nonce="%s", uri="%s", ' \               'response="%s"' % (user, realm, nonce, req.selector,                                  respdig)        if opaque:            base += ', opaque="%s"' % opaque        if entdig:            base += ', digest="%s"' % entdig        base += ', algorithm="%s"' % algorithm        if qop:            base += ', qop=auth, nc=%s, cnonce="%s"' % (ncvalue, cnonce)        return base     def get_algorithm_impls(self, algorithm):        # lambdas assume digest modules are imported at the top level        if algorithm == 'MD5':            H = lambda x: hashlib.md5(x.encode("ascii")).hexdigest()        elif algorithm == 'SHA':            H = lambda x: hashlib.sha1(x.encode("ascii")).hexdigest()        # XXX MD5-sess        else:            raise ValueError("Unsupported digest authentication "                             "algorithm %r" % algorithm)        KD = lambda s, d: H("%s:%s" % (s, d))        return H, KD     def get_entity_digest(self, data, chal):        # XXX not implemented yet        return None  class HTTPDigestAuthHandler(BaseHandler, AbstractDigestAuthHandler):    """An authentication protocol defined by RFC 2069     Digest authentication improves on basic authentication because it    does not transmit passwords in the clear.    """     auth_header = 'Authorization'    handler_order = 490  # before Basic auth     def http_error_401(self, req, fp, code, msg, headers):        host = urlparse(req.full_url)[1]        retry = self.http_error_auth_reqed('www-authenticate',                                           host, req, headers)        self.reset_retry_count()        return retry  class ProxyDigestAuthHandler(BaseHandler, AbstractDigestAuthHandler):     auth_header = 'Proxy-Authorization'    handler_order = 490  # before Basic auth     def http_error_407(self, req, fp, code, msg, headers):        host = req.host        retry = self.http_error_auth_reqed('proxy-authenticate',                                           host, req, headers)        self.reset_retry_count()        return retry class AbstractHTTPHandler(BaseHandler):     def __init__(self, debuglevel=0):        self._debuglevel = debuglevel     def set_http_debuglevel(self, level):        self._debuglevel = level     def _get_content_length(self, request):        return http.client.HTTPConnection._get_content_length(            request.data,            request.get_method())     def do_request_(self, request):        host = request.host        if not host:            raise URLError('no host given')         if request.data is not None:  # POST            data = request.data            if isinstance(data, str):                msg = "POST data should be bytes, an iterable of bytes, " \                      "or a file object. It cannot be of type str."                raise TypeError(msg)            if not request.has_header('Content-type'):                request.add_unredirected_header(                    'Content-type',                    'application/x-www-form-urlencoded')            if (not request.has_header('Content-length')                    and not request.has_header('Transfer-encoding')):                content_length = self._get_content_length(request)                if content_length is not None:                    request.add_unredirected_header(                            'Content-length', str(content_length))                else:                    request.add_unredirected_header(                            'Transfer-encoding', 'chunked')         sel_host = host        if request.has_proxy():            scheme, sel = _splittype(request.selector)            sel_host, sel_path = _splithost(sel)        if not request.has_header('Host'):            request.add_unredirected_header('Host', sel_host)        for name, value in self.parent.addheaders:            name = name.capitalize()            if not request.has_header(name):                request.add_unredirected_header(name, value)         return request     def do_open(self, http_class, req, **http_conn_args):        """Return an HTTPResponse object for the request, using http_class.         http_class must implement the HTTPConnection API from http.client.        """        host = req.host        if not host:            raise URLError('no host given')         # will parse host:port        h = http_class(host, timeout=req.timeout, **http_conn_args)        h.set_debuglevel(self._debuglevel)         headers = dict(req.unredirected_hdrs)        headers.update({k: v for k, v in req.headers.items()                        if k not in headers})         # TODO(jhylton): Should this be redesigned to handle        # persistent connections?         # We want to make an HTTP/1.1 request, but the addinfourl        # class isn't prepared to deal with a persistent connection.        # It will try to read all remaining data from the socket,        # which will block while the server waits for the next request.        # So make sure the connection gets closed after the (only)        # request.        headers["Connection"] = "close"        headers = {name.title(): val for name, val in headers.items()}         if req._tunnel_host:            tunnel_headers = {}            proxy_auth_hdr = "Proxy-Authorization"            if proxy_auth_hdr in headers:                tunnel_headers[proxy_auth_hdr] = headers[proxy_auth_hdr]                # Proxy-Authorization should not be sent to origin                # server.                del headers[proxy_auth_hdr]            h.set_tunnel(req._tunnel_host, headers=tunnel_headers)         try:            try:                h.request(req.get_method(), req.selector, req.data, headers,                          encode_chunked=req.has_header('Transfer-encoding'))            except OSError as err: # timeout error                raise URLError(err)            r = h.getresponse()        except:            h.close()            raise         # If the server does not send us a 'Connection: close' header,        # HTTPConnection assumes the socket should be left open. Manually        # mark the socket to be closed when this response object goes away.        if h.sock:            h.sock.close()            h.sock = None         r.url = req.get_full_url()        # This line replaces the .msg attribute of the HTTPResponse        # with .headers, because urllib clients expect the response to        # have the reason in .msg.  It would be good to mark this        # attribute is deprecated and get then to use info() or        # .headers.        r.msg = r.reason        return r  class HTTPHandler(AbstractHTTPHandler):     def http_open(self, req):        return self.do_open(http.client.HTTPConnection, req)     http_request = AbstractHTTPHandler.do_request_ if hasattr(http.client, 'HTTPSConnection'):     class HTTPSHandler(AbstractHTTPHandler):         def __init__(self, debuglevel=0, context=None, check_hostname=None):            AbstractHTTPHandler.__init__(self, debuglevel)            self._context = context            self._check_hostname = check_hostname         def https_open(self, req):            return self.do_open(http.client.HTTPSConnection, req,                context=self._context, check_hostname=self._check_hostname)         https_request = AbstractHTTPHandler.do_request_     __all__.append('HTTPSHandler') class HTTPCookieProcessor(BaseHandler):    def __init__(self, cookiejar=None):        import http.cookiejar        if cookiejar is None:            cookiejar = http.cookiejar.CookieJar()        self.cookiejar = cookiejar     def http_request(self, request):        self.cookiejar.add_cookie_header(request)        return request     def http_response(self, request, response):        self.cookiejar.extract_cookies(response, request)        return response     https_request = http_request    https_response = http_response class UnknownHandler(BaseHandler):    def unknown_open(self, req):        type = req.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 = elt.split('=', 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 comma-separated lists where the elements of    the list may include quoted-strings.  A quoted-string could    contain a comma.  A non-quoted string could have quotes in the    middle.  Neither commas nor quotes count if they are escaped.    Only double-quotes count, not single-quotes.    """    res = []    part = ''     escape = quote = False    for cur in s:        if escape:            part += cur            escape = False            continue        if quote:            if cur == '\\':                escape = True                continue            elif cur == '"':                quote = False            part += cur            continue         if cur == ',':            res.append(part)            part = ''            continue         if cur == '"':            quote = True         part += cur     # append last part    if part:        res.append(part)     return [part.strip() for part in res] class FileHandler(BaseHandler):    # Use local file or FTP depending on form of URL    def file_open(self, req):        url = req.selector        if url[:2] == '//' and url[2:3] != '/' and (req.host and                req.host != 'localhost'):            if not req.host in self.get_names():                raise URLError("file:// scheme is supported only on localhost")        else:            return self.open_local_file(req)     # names for the localhost    names = None    def get_names(self):        if FileHandler.names is None:            try:                FileHandler.names = tuple(                    socket.gethostbyname_ex('localhost')[2] +                    socket.gethostbyname_ex(socket.gethostname())[2])            except socket.gaierror:                FileHandler.names = (socket.gethostbyname('localhost'),)        return FileHandler.names     # not entirely sure what the rules are here    def open_local_file(self, req):        import email.utils        import mimetypes        host = req.host        filename = req.selector        localfile = url2pathname(filename)        try:            stats = os.stat(localfile)            size = stats.st_size            modified = email.utils.formatdate(stats.st_mtime, usegmt=True)            mtype = mimetypes.guess_type(filename)[0]            headers = email.message_from_string(                'Content-type: %s\nContent-length: %d\nLast-modified: %s\n' %                (mtype or 'text/plain', size, modified))            if host:                host, port = _splitport(host)            if not host or \                (not port and _safe_gethostbyname(host) in self.get_names()):                if host:                    origurl = 'file://' + host + filename                else:                    origurl = 'file://' + filename                return addinfourl(open(localfile, 'rb'), headers, origurl)        except OSError as exp:            raise URLError(exp)        raise URLError('file not on local host') def _safe_gethostbyname(host):    try:        return socket.gethostbyname(host)    except socket.gaierror:        return None class FTPHandler(BaseHandler):    def ftp_open(self, req):        import ftplib        import mimetypes        host = req.host        if not host:            raise URLError('ftp error: no host given')        host, port = _splitport(host)        if port is None:            port = ftplib.FTP_PORT        else:            port = int(port)         # username/password handling        user, host = _splituser(host)        if user:            user, passwd = _splitpasswd(user)        else:            passwd = None        host = unquote(host)        user = user or ''        passwd = passwd or ''         try:            host = socket.gethostbyname(host)        except OSError as msg:            raise URLError(msg)        path, attrs = _splitattr(req.selector)        dirs = path.split('/')        dirs = list(map(unquote, dirs))        dirs, file = dirs[:-1], dirs[-1]        if dirs and not dirs[0]:            dirs = dirs[1:]        try:            fw = self.connect_ftp(user, passwd, host, port, dirs, req.timeout)            type = file and 'I' or 'D'            for attr in attrs:                attr, value = _splitvalue(attr)                if attr.lower() == 'type' and \                   value in ('a', 'A', 'i', 'I', 'd', 'D'):                    type = value.upper()            fp, retrlen = fw.retrfile(file, type)            headers = ""            mtype = mimetypes.guess_type(req.full_url)[0]            if mtype:                headers += "Content-type: %s\n" % mtype            if retrlen is not None and retrlen >= 0:                headers += "Content-length: %d\n" % retrlen            headers = email.message_from_string(headers)            return addinfourl(fp, headers, req.full_url)        except ftplib.all_errors as exp:            exc = URLError('ftp error: %r' % exp)            raise exc.with_traceback(sys.exc_info()[2])     def connect_ftp(self, user, passwd, host, port, dirs, timeout):        return ftpwrapper(user, passwd, host, port, dirs, timeout,                          persistent=False) 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, timeout):        key = user, host, port, '/'.join(dirs), timeout        if key in self.cache:            self.timeout[key] = time.time() + self.delay        else:            self.cache[key] = ftpwrapper(user, passwd, host, port,                                         dirs, timeout)            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 list(self.timeout.items()):                if v < t:                    self.cache[k].close()                    del self.cache[k]                    del self.timeout[k]        self.soonest = min(list(self.timeout.values()))         # then check the size        if len(self.cache) == self.max_conns:            for k, v in list(self.timeout.items()):                if v == self.soonest:                    del self.cache[k]                    del self.timeout[k]                    break            self.soonest = min(list(self.timeout.values()))     def clear_cache(self):        for conn in self.cache.values():            conn.close()        self.cache.clear()        self.timeout.clear() class DataHandler(BaseHandler):    def data_open(self, req):        # data URLs as specified in RFC 2397.        #        # ignores POSTed data        #        # syntax:        # dataurl   := "data:" [ mediatype ] [ ";base64" ] "," data        # mediatype := [ type "/" subtype ] *( ";" parameter )        # data      := *urlchar        # parameter := attribute "=" value        url = req.full_url         scheme, data = url.split(":",1)        mediatype, data = data.split(",",1)         # Disallow control characters within mediatype.        if re.search(r"[\x00-\x1F\x7F]", mediatype):            raise ValueError(                "Control characters not allowed in data: mediatype")         # even base64 encoded data URLs might be quoted so unquote in any case:        data = unquote_to_bytes(data)        if mediatype.endswith(";base64"):            data = base64.decodebytes(data)            mediatype = mediatype[:-7]         if not mediatype:            mediatype = "text/plain;charset=US-ASCII"         headers = email.message_from_string("Content-type: %s\nContent-length: %d\n" %            (mediatype, len(data)))         return addinfourl(io.BytesIO(data), headers, url)  # Code move from the old urllib module MAXFTPCACHE = 10        # Trim the ftp cache beyond this size # Helper for non-unix systemsif os.name == 'nt':    from nturl2path import url2pathname, pathname2urlelse:    def url2pathname(pathname):        """OS-specific conversion from a relative URL of the 'file' scheme        to a file system path; not recommended for general use."""        return unquote(pathname)     def pathname2url(pathname):        """OS-specific conversion from a file system path to a relative URL        of the 'file' scheme; not recommended for general use."""        return quote(pathname)  ftpcache = {}  class URLopener:    """Class to open URLs.    This is a class rather than just a subroutine because we may need    more than one set of global protocol-specific options.    Note -- this is a base class for those who don't want the    automatic handling of errors type 302 (relocated) and 401    (authorization needed)."""     __tempfiles = None     version = "Python-urllib/%s" % __version__     # Constructor    def __init__(self, proxies=None, **x509):        msg = "%(class)s style of invoking requests is deprecated. " \              "Use newer urlopen functions/methods" % {'class': self.__class__.__name__}        warnings.warn(msg, DeprecationWarning, stacklevel=3)        if proxies is None:            proxies = getproxies()        assert hasattr(proxies, 'keys'), "proxies must be a mapping"        self.proxies = proxies        self.key_file = x509.get('key_file')        self.cert_file = x509.get('cert_file')        self.addheaders = [('User-Agent', self.version), ('Accept', '*/*')]        self.__tempfiles = []        self.__unlink = os.unlink # See cleanup()        self.tempcache = None        # Undocumented feature: if you assign {} to tempcache,        # it is used to cache files retrieved with        # self.retrieve().  This is not enabled by default        # since it does not work for changing documents (and I        # haven't got the logic to check expiration headers        # yet).        self.ftpcache = ftpcache        # Undocumented feature: you can use a different        # ftp cache by assigning to the .ftpcache member;        # in case you want logically independent URL openers        # XXX This is not threadsafe.  Bah.     def __del__(self):        self.close()     def close(self):        self.cleanup()     def cleanup(self):        # This code sometimes runs when the rest of this module        # has already been deleted, so it can't use any globals        # or import anything.        if self.__tempfiles:            for file in self.__tempfiles:                try:                    self.__unlink(file)                except OSError:                    pass            del self.__tempfiles[:]        if self.tempcache:            self.tempcache.clear()     def addheader(self, *args):        """Add a header to be used by the HTTP interface only        e.g. u.addheader('Accept', 'sound/basic')"""        self.addheaders.append(args)     # External interface    def open(self, fullurl, data=None):        """Use URLopener().open(file) instead of open(file, 'r')."""        fullurl = unwrap(_to_bytes(fullurl))        fullurl = quote(fullurl, safe="%/:=&?~#+!$,;'@()*[]|")        if self.tempcache and fullurl in self.tempcache:            filename, headers = self.tempcache[fullurl]            fp = open(filename, 'rb')            return addinfourl(fp, headers, fullurl)        urltype, url = _splittype(fullurl)        if not urltype:            urltype = 'file'        if urltype in self.proxies:            proxy = self.proxies[urltype]            urltype, proxyhost = _splittype(proxy)            host, selector = _splithost(proxyhost)            url = (host, fullurl) # Signal special case to open_*()        else:            proxy = None        name = 'open_' + urltype        self.type = urltype        name = name.replace('-', '_')        if not hasattr(self, name) or name == 'open_local_file':            if proxy:                return self.open_unknown_proxy(proxy, fullurl, data)            else:                return self.open_unknown(fullurl, data)        try:            if data is None:                return getattr(self, name)(url)            else:                return getattr(self, name)(url, data)        except (HTTPError, URLError):            raise        except OSError as msg:            raise OSError('socket error', msg).with_traceback(sys.exc_info()[2])     def open_unknown(self, fullurl, data=None):        """Overridable interface to open unknown URL type."""        type, url = _splittype(fullurl)        raise OSError('url error', 'unknown url type', type)     def open_unknown_proxy(self, proxy, fullurl, data=None):        """Overridable interface to open unknown URL type."""        type, url = _splittype(fullurl)        raise OSError('url error', 'invalid proxy for %s' % type, proxy)     # External interface    def retrieve(self, url, filename=None, reporthook=None, data=None):        """retrieve(url) returns (filename, headers) for a local object        or (tempfilename, headers) for a remote object."""        url = unwrap(_to_bytes(url))        if self.tempcache and url in self.tempcache:            return self.tempcache[url]        type, url1 = _splittype(url)        if filename is None and (not type or type == 'file'):            try:                fp = self.open_local_file(url1)                hdrs = fp.info()                fp.close()                return url2pathname(_splithost(url1)[1]), hdrs            except OSError:                pass        fp = self.open(url, data)        try:            headers = fp.info()            if filename:                tfp = open(filename, 'wb')            else:                garbage, path = _splittype(url)                garbage, path = _splithost(path or "")                path, garbage = _splitquery(path or "")                path, garbage = _splitattr(path or "")                suffix = os.path.splitext(path)[1]                (fd, filename) = tempfile.mkstemp(suffix)                self.__tempfiles.append(filename)                tfp = os.fdopen(fd, 'wb')            try:                result = filename, headers                if self.tempcache is not None:                    self.tempcache[url] = result                bs = 1024*8                size = -1                read = 0                blocknum = 0                if "content-length" in headers:                    size = int(headers["Content-Length"])                if reporthook:                    reporthook(blocknum, bs, size)                while 1:                    block = fp.read(bs)                    if not block:                        break                    read += len(block)                    tfp.write(block)                    blocknum += 1                    if reporthook:                        reporthook(blocknum, bs, size)            finally:                tfp.close()        finally:            fp.close()         # raise exception if actual size does not match content-length header        if size >= 0 and read < size:            raise ContentTooShortError(                "retrieval incomplete: got only %i out of %i bytes"                % (read, size), result)         return result     # Each method named open_<type> knows how to open that type of URL     def _open_generic_http(self, connection_factory, url, data):        """Make an HTTP connection using connection_class.         This is an internal method that should be called from        open_http() or open_https().         Arguments:        - connection_factory should take a host name and return an          HTTPConnection instance.        - url is the url to retrieval or a host, relative-path pair.        - data is payload for a POST request or None.        """         user_passwd = None        proxy_passwd= None        if isinstance(url, str):            host, selector = _splithost(url)            if host:                user_passwd, host = _splituser(host)                host = unquote(host)            realhost = host        else:            host, selector = url            # check whether the proxy contains authorization information            proxy_passwd, host = _splituser(host)            # now we proceed with the url we want to obtain            urltype, rest = _splittype(selector)            url = rest            user_passwd = None            if urltype.lower() != 'http':                realhost = None            else:                realhost, rest = _splithost(rest)                if realhost:                    user_passwd, realhost = _splituser(realhost)                if user_passwd:                    selector = "%s://%s%s" % (urltype, realhost, rest)                if proxy_bypass(realhost):                    host = realhost         if not host: raise OSError('http error', 'no host given')         if proxy_passwd:            proxy_passwd = unquote(proxy_passwd)            proxy_auth = base64.b64encode(proxy_passwd.encode()).decode('ascii')        else:            proxy_auth = None         if user_passwd:            user_passwd = unquote(user_passwd)            auth = base64.b64encode(user_passwd.encode()).decode('ascii')        else:            auth = None        http_conn = connection_factory(host)        headers = {}        if proxy_auth:            headers["Proxy-Authorization"] = "Basic %s" % proxy_auth        if auth:            headers["Authorization"] =  "Basic %s" % auth        if realhost:            headers["Host"] = realhost         # Add Connection:close as we don't support persistent connections yet.        # This helps in closing the socket and avoiding ResourceWarning         headers["Connection"] = "close"         for header, value in self.addheaders:            headers[header] = value         if data is not None:            headers["Content-Type"] = "application/x-www-form-urlencoded"            http_conn.request("POST", selector, data, headers)        else:            http_conn.request("GET", selector, headers=headers)         try:            response = http_conn.getresponse()        except http.client.BadStatusLine:            # something went wrong with the HTTP status line            raise URLError("http protocol error: bad status line")         # According to RFC 2616, "2xx" code indicates that the client's        # request was successfully received, understood, and accepted.        if 200 <= response.status < 300:            return addinfourl(response, response.msg, "http:" + url,                              response.status)        else:            return self.http_error(                url, response.fp,                response.status, response.reason, response.msg, data)     def open_http(self, url, data=None):        """Use HTTP protocol."""        return self._open_generic_http(http.client.HTTPConnection, url, data)     def http_error(self, url, fp, errcode, errmsg, headers, data=None):        """Handle http errors.         Derived class can override this, or provide specific handlers        named http_error_DDD where DDD is the 3-digit error code."""        # First check if there's a specific handler for this error        name = 'http_error_%d' % errcode        if hasattr(self, name):            method = getattr(self, name)            if data is None:                result = method(url, fp, errcode, errmsg, headers)            else:                result = method(url, fp, errcode, errmsg, headers, data)            if result: return result        return self.http_error_default(url, fp, errcode, errmsg, headers)     def http_error_default(self, url, fp, errcode, errmsg, headers):        """Default error handler: close the connection and raise OSError."""        fp.close()        raise HTTPError(url, errcode, errmsg, headers, None)     if _have_ssl:        def _https_connection(self, host):            return http.client.HTTPSConnection(host,                                           key_file=self.key_file,                                           cert_file=self.cert_file)         def open_https(self, url, data=None):            """Use HTTPS protocol."""            return self._open_generic_http(self._https_connection, url, data)     def open_file(self, url):        """Use local file or FTP depending on form of URL."""        if not isinstance(url, str):            raise URLError('file error: proxy support for file protocol currently not implemented')        if url[:2] == '//' and url[2:3] != '/' and url[2:12].lower() != 'localhost/':            raise ValueError("file:// scheme is supported only on localhost")        else:            return self.open_local_file(url)     def open_local_file(self, url):        """Use local file."""        import email.utils        import mimetypes        host, file = _splithost(url)        localname = url2pathname(file)        try:            stats = os.stat(localname)        except OSError as e:            raise URLError(e.strerror, e.filename)        size = stats.st_size        modified = email.utils.formatdate(stats.st_mtime, usegmt=True)        mtype = mimetypes.guess_type(url)[0]        headers = email.message_from_string(            'Content-Type: %s\nContent-Length: %d\nLast-modified: %s\n' %            (mtype or 'text/plain', size, modified))        if not host:            urlfile = file            if file[:1] == '/':                urlfile = 'file://' + file            return addinfourl(open(localname, 'rb'), headers, urlfile)        host, port = _splitport(host)        if (not port           and socket.gethostbyname(host) in ((localhost(),) + thishost())):            urlfile = file            if file[:1] == '/':                urlfile = 'file://' + file            elif file[:2] == './':                raise ValueError("local file url may start with / or file:. Unknown url of type: %s" % url)            return addinfourl(open(localname, 'rb'), headers, urlfile)        raise URLError('local file error: not on local host')     def open_ftp(self, url):        """Use FTP protocol."""        if not isinstance(url, str):            raise URLError('ftp error: proxy support for ftp protocol currently not implemented')        import mimetypes        host, path = _splithost(url)        if not host: raise URLError('ftp error: no host given')        host, port = _splitport(host)        user, host = _splituser(host)        if user: user, passwd = _splitpasswd(user)        else: passwd = None        host = unquote(host)        user = unquote(user or '')        passwd = unquote(passwd or '')        host = socket.gethostbyname(host)        if not port:            import ftplib            port = ftplib.FTP_PORT        else:            port = int(port)        path, attrs = _splitattr(path)        path = unquote(path)        dirs = path.split('/')        dirs, file = dirs[:-1], dirs[-1]        if dirs and not dirs[0]: dirs = dirs[1:]        if dirs and not dirs[0]: dirs[0] = '/'        key = user, host, port, '/'.join(dirs)        # XXX thread unsafe!        if len(self.ftpcache) > MAXFTPCACHE:            # Prune the cache, rather arbitrarily            for k in list(self.ftpcache):                if k != key:                    v = self.ftpcache[k]                    del self.ftpcache[k]                    v.close()        try:            if key not in self.ftpcache:                self.ftpcache[key] = \                    ftpwrapper(user, passwd, host, port, dirs)            if not file: type = 'D'            else: type = 'I'            for attr in attrs:                attr, value = _splitvalue(attr)                if attr.lower() == 'type' and \                   value in ('a', 'A', 'i', 'I', 'd', 'D'):                    type = value.upper()            (fp, retrlen) = self.ftpcache[key].retrfile(file, type)            mtype = mimetypes.guess_type("ftp:" + url)[0]            headers = ""            if mtype:                headers += "Content-Type: %s\n" % mtype            if retrlen is not None and retrlen >= 0:                headers += "Content-Length: %d\n" % retrlen            headers = email.message_from_string(headers)            return addinfourl(fp, headers, "ftp:" + url)        except ftperrors() as exp:            raise URLError('ftp error %r' % exp).with_traceback(sys.exc_info()[2])     def open_data(self, url, data=None):        """Use "data" URL."""        if not isinstance(url, str):            raise URLError('data error: proxy support for data protocol currently not implemented')        # ignore POSTed data        #        # syntax of data URLs:        # dataurl   := "data:" [ mediatype ] [ ";base64" ] "," data        # mediatype := [ type "/" subtype ] *( ";" parameter )        # data      := *urlchar        # parameter := attribute "=" value        try:            [type, data] = url.split(',', 1)        except ValueError:            raise OSError('data error', 'bad data URL')        if not type:            type = 'text/plain;charset=US-ASCII'        semi = type.rfind(';')        if semi >= 0 and '=' not in type[semi:]:            encoding = type[semi+1:]            type = type[:semi]        else:            encoding = ''        msg = []        msg.append('Date: %s'%time.strftime('%a, %d %b %Y %H:%M:%S GMT',                                            time.gmtime(time.time())))        msg.append('Content-type: %s' % type)        if encoding == 'base64':            # XXX is this encoding/decoding ok?            data = base64.decodebytes(data.encode('ascii')).decode('latin-1')        else:            data = unquote(data)        msg.append('Content-Length: %d' % len(data))        msg.append('')        msg.append(data)        msg = '\n'.join(msg)        headers = email.message_from_string(msg)        f = io.StringIO(msg)        #f.fileno = None     # needed for addinfourl        return addinfourl(f, headers, url)  class FancyURLopener(URLopener):    """Derived class with handlers for errors we can handle (perhaps)."""     def __init__(self, *args, **kwargs):        URLopener.__init__(self, *args, **kwargs)        self.auth_cache = {}        self.tries = 0        self.maxtries = 10     def http_error_default(self, url, fp, errcode, errmsg, headers):        """Default error handling -- don't raise an exception."""        return addinfourl(fp, headers, "http:" + url, errcode)     def http_error_302(self, url, fp, errcode, errmsg, headers, data=None):        """Error 302 -- relocated (temporarily)."""        self.tries += 1        try:            if self.maxtries and self.tries >= self.maxtries:                if hasattr(self, "http_error_500"):                    meth = self.http_error_500                else:                    meth = self.http_error_default                return meth(url, fp, 500,                            "Internal Server Error: Redirect Recursion",                            headers)            result = self.redirect_internal(url, fp, errcode, errmsg,                                            headers, data)            return result        finally:            self.tries = 0     def redirect_internal(self, url, fp, errcode, errmsg, headers, data):        if 'location' in headers:            newurl = headers['location']        elif 'uri' in headers:            newurl = headers['uri']        else:            return        fp.close()         # In case the server sent a relative URL, join with original:        newurl = urljoin(self.type + ":" + url, newurl)         urlparts = urlparse(newurl)         # For security reasons, we don't allow redirection to anything other        # than http, https and ftp.         # We are using newer HTTPError with older redirect_internal method        # This older method will get deprecated in 3.3         if urlparts.scheme not in ('http', 'https', 'ftp', ''):            raise HTTPError(newurl, errcode,                            errmsg +                            " Redirection to url '%s' is not allowed." % newurl,                            headers, fp)         return self.open(newurl)     def http_error_301(self, url, fp, errcode, errmsg, headers, data=None):        """Error 301 -- also relocated (permanently)."""        return self.http_error_302(url, fp, errcode, errmsg, headers, data)     def http_error_303(self, url, fp, errcode, errmsg, headers, data=None):        """Error 303 -- also relocated (essentially identical to 302)."""        return self.http_error_302(url, fp, errcode, errmsg, headers, data)     def http_error_307(self, url, fp, errcode, errmsg, headers, data=None):        """Error 307 -- relocated, but turn POST into error."""        if data is None:            return self.http_error_302(url, fp, errcode, errmsg, headers, data)        else:            return self.http_error_default(url, fp, errcode, errmsg, headers)     def http_error_401(self, url, fp, errcode, errmsg, headers, data=None,            retry=False):        """Error 401 -- authentication required.        This function supports Basic authentication only."""        if 'www-authenticate' not in headers:            URLopener.http_error_default(self, url, fp,                                         errcode, errmsg, headers)        stuff = headers['www-authenticate']        match = re.match('[ \t]*([^ \t]+)[ \t]+realm="([^"]*)"', stuff)        if not match:            URLopener.http_error_default(self, url, fp,                                         errcode, errmsg, headers)        scheme, realm = match.groups()        if scheme.lower() != 'basic':            URLopener.http_error_default(self, url, fp,                                         errcode, errmsg, headers)        if not retry:            URLopener.http_error_default(self, url, fp, errcode, errmsg,                    headers)        name = 'retry_' + self.type + '_basic_auth'        if data is None:            return getattr(self,name)(url, realm)        else:            return getattr(self,name)(url, realm, data)     def http_error_407(self, url, fp, errcode, errmsg, headers, data=None,            retry=False):        """Error 407 -- proxy authentication required.        This function supports Basic authentication only."""        if 'proxy-authenticate' not in headers:            URLopener.http_error_default(self, url, fp,                                         errcode, errmsg, headers)        stuff = headers['proxy-authenticate']        match = re.match('[ \t]*([^ \t]+)[ \t]+realm="([^"]*)"', stuff)        if not match:            URLopener.http_error_default(self, url, fp,                                         errcode, errmsg, headers)        scheme, realm = match.groups()        if scheme.lower() != 'basic':            URLopener.http_error_default(self, url, fp,                                         errcode, errmsg, headers)        if not retry:            URLopener.http_error_default(self, url, fp, errcode, errmsg,                    headers)        name = 'retry_proxy_' + self.type + '_basic_auth'        if data is None:            return getattr(self,name)(url, realm)        else:            return getattr(self,name)(url, realm, data)     def retry_proxy_http_basic_auth(self, url, realm, data=None):        host, selector = _splithost(url)        newurl = 'http://' + host + selector        proxy = self.proxies['http']        urltype, proxyhost = _splittype(proxy)        proxyhost, proxyselector = _splithost(proxyhost)        i = proxyhost.find('@') + 1        proxyhost = proxyhost[i:]        user, passwd = self.get_user_passwd(proxyhost, realm, i)        if not (user or passwd): return None        proxyhost = "%s:%s@%s" % (quote(user, safe=''),                                  quote(passwd, safe=''), proxyhost)        self.proxies['http'] = 'http://' + proxyhost + proxyselector        if data is None:            return self.open(newurl)        else:            return self.open(newurl, data)     def retry_proxy_https_basic_auth(self, url, realm, data=None):        host, selector = _splithost(url)        newurl = 'https://' + host + selector        proxy = self.proxies['https']        urltype, proxyhost = _splittype(proxy)        proxyhost, proxyselector = _splithost(proxyhost)        i = proxyhost.find('@') + 1        proxyhost = proxyhost[i:]        user, passwd = self.get_user_passwd(proxyhost, realm, i)        if not (user or passwd): return None        proxyhost = "%s:%s@%s" % (quote(user, safe=''),                                  quote(passwd, safe=''), proxyhost)        self.proxies['https'] = 'https://' + proxyhost + proxyselector        if data is None:            return self.open(newurl)        else:            return self.open(newurl, data)     def retry_http_basic_auth(self, url, realm, data=None):        host, selector = _splithost(url)        i = host.find('@') + 1        host = host[i:]        user, passwd = self.get_user_passwd(host, realm, i)        if not (user or passwd): return None        host = "%s:%s@%s" % (quote(user, safe=''),                             quote(passwd, safe=''), host)        newurl = 'http://' + host + selector        if data is None:            return self.open(newurl)        else:            return self.open(newurl, data)     def retry_https_basic_auth(self, url, realm, data=None):        host, selector = _splithost(url)        i = host.find('@') + 1        host = host[i:]        user, passwd = self.get_user_passwd(host, realm, i)        if not (user or passwd): return None        host = "%s:%s@%s" % (quote(user, safe=''),                             quote(passwd, safe=''), host)        newurl = 'https://' + host + selector        if data is None:            return self.open(newurl)        else:            return self.open(newurl, data)     def get_user_passwd(self, host, realm, clear_cache=0):        key = realm + '@' + host.lower()        if key in self.auth_cache:            if clear_cache:                del self.auth_cache[key]            else:                return self.auth_cache[key]        user, passwd = self.prompt_user_passwd(host, realm)        if user or passwd: self.auth_cache[key] = (user, passwd)        return user, passwd     def prompt_user_passwd(self, host, realm):        """Override this in a GUI environment!"""        import getpass        try:            user = input("Enter username for %s at %s: " % (realm, host))            passwd = getpass.getpass("Enter password for %s in %s at %s: " %                (user, realm, host))            return user, passwd        except KeyboardInterrupt:            print()            return None, None  # Utility functions _localhost = Nonedef localhost():    """Return the IP address of the magic hostname 'localhost'."""    global _localhost    if _localhost is None:        _localhost = socket.gethostbyname('localhost')    return _localhost _thishost = Nonedef thishost():    """Return the IP addresses of the current host."""    global _thishost    if _thishost is None:        try:            _thishost = tuple(socket.gethostbyname_ex(socket.gethostname())[2])        except socket.gaierror:            _thishost = tuple(socket.gethostbyname_ex('localhost')[2])    return _thishost _ftperrors = Nonedef ftperrors():    """Return the set of errors raised by the FTP class."""    global _ftperrors    if _ftperrors is None:        import ftplib        _ftperrors = ftplib.all_errors    return _ftperrors _noheaders = Nonedef noheaders():    """Return an empty email Message object."""    global _noheaders    if _noheaders is None:        _noheaders = email.message_from_string("")    return _noheaders  # Utility classes class ftpwrapper:    """Class used by open_ftp() for cache of open FTP connections."""     def __init__(self, user, passwd, host, port, dirs, timeout=None,                 persistent=True):        self.user = user        self.passwd = passwd        self.host = host        self.port = port        self.dirs = dirs        self.timeout = timeout        self.refcount = 0        self.keepalive = persistent        try:            self.init()        except:            self.close()            raise     def init(self):        import ftplib        self.busy = 0        self.ftp = ftplib.FTP()        self.ftp.connect(self.host, self.port, self.timeout)        self.ftp.login(self.user, self.passwd)        _target = '/'.join(self.dirs)        self.ftp.cwd(_target)     def retrfile(self, file, type):        import ftplib        self.endtransfer()        if type in ('d', 'D'): cmd = 'TYPE A'; isdir = 1        else: cmd = 'TYPE ' + type; isdir = 0        try:            self.ftp.voidcmd(cmd)        except ftplib.all_errors:            self.init()            self.ftp.voidcmd(cmd)        conn = None        if file and not isdir:            # Try to retrieve as a file            try:                cmd = 'RETR ' + file                conn, retrlen = self.ftp.ntransfercmd(cmd)            except ftplib.error_perm as reason:                if str(reason)[:3] != '550':                    raise URLError('ftp error: %r' % reason).with_traceback(                        sys.exc_info()[2])        if not conn:            # Set transfer mode to ASCII!            self.ftp.voidcmd('TYPE A')            # Try a directory listing. Verify that directory exists.            if file:                pwd = self.ftp.pwd()                try:                    try:                        self.ftp.cwd(file)                    except ftplib.error_perm as reason:                        raise URLError('ftp error: %r' % reason) from reason                finally:                    self.ftp.cwd(pwd)                cmd = 'LIST ' + file            else:                cmd = 'LIST'            conn, retrlen = self.ftp.ntransfercmd(cmd)        self.busy = 1         ftpobj = addclosehook(conn.makefile('rb'), self.file_close)        self.refcount += 1        conn.close()        # Pass back both a suitably decorated object and a retrieval length        return (ftpobj, retrlen)     def endtransfer(self):        self.busy = 0     def close(self):        self.keepalive = False        if self.refcount <= 0:            self.real_close()     def file_close(self):        self.endtransfer()        self.refcount -= 1        if self.refcount <= 0 and not self.keepalive:            self.real_close()     def real_close(self):        self.endtransfer()        try:            self.ftp.close()        except ftperrors():            pass # Proxy handlingdef getproxies_environment():    """Return a dictionary of scheme -> proxy server URL mappings.     Scan the environment for variables named <scheme>_proxy;    this seems to be the standard convention.  If you need a    different way, you can pass a proxies dictionary to the    [Fancy]URLopener constructor.     """    proxies = {}    # in order to prefer lowercase variables, process environment in    # two passes: first matches any, second pass matches lowercase only    for name, value in os.environ.items():        name = name.lower()        if value and name[-6:] == '_proxy':            proxies[name[:-6]] = value    # CVE-2016-1000110 - If we are running as CGI script, forget HTTP_PROXY    # (non-all-lowercase) as it may be set from the web server by a "Proxy:"    # header from the client    # If "proxy" is lowercase, it will still be used thanks to the next block    if 'REQUEST_METHOD' in os.environ:        proxies.pop('http', None)    for name, value in os.environ.items():        if name[-6:] == '_proxy':            name = name.lower()            if value:                proxies[name[:-6]] = value            else:                proxies.pop(name[:-6], None)    return proxies def proxy_bypass_environment(host, proxies=None):    """Test if proxies should not be used for a particular host.     Checks the proxy dict for the value of no_proxy, which should    be a list of comma separated DNS suffixes, or '*' for all hosts.     """    if proxies is None:        proxies = getproxies_environment()    # don't bypass, if no_proxy isn't specified    try:        no_proxy = proxies['no']    except KeyError:        return False    # '*' is special case for always bypass    if no_proxy == '*':        return True    host = host.lower()    # strip port off host    hostonly, port = _splitport(host)    # check if the host ends with any of the DNS suffixes    for name in no_proxy.split(','):        name = name.strip()        if name:            name = name.lstrip('.')  # ignore leading dots            name = name.lower()            if hostonly == name or host == name:                return True            name = '.' + name            if hostonly.endswith(name) or host.endswith(name):                return True    # otherwise, don't bypass    return False  # This code tests an OSX specific data structure but is testable on all# platformsdef _proxy_bypass_macosx_sysconf(host, proxy_settings):    """    Return True iff this host shouldn't be accessed using a proxy     This function uses the MacOSX framework SystemConfiguration    to fetch the proxy information.     proxy_settings come from _scproxy._get_proxy_settings or get mocked ie:    { 'exclude_simple': bool,      'exceptions': ['foo.bar', '*.bar.com', '127.0.0.1', '10.1', '10.0/16']    }    """    from fnmatch import fnmatch    from ipaddress import AddressValueError, IPv4Address     hostonly, port = _splitport(host)     def ip2num(ipAddr):        parts = ipAddr.split('.')        parts = list(map(int, parts))        if len(parts) != 4:            parts = (parts + [0, 0, 0, 0])[:4]        return (parts[0] << 24) | (parts[1] << 16) | (parts[2] << 8) | parts[3]     # Check for simple host names:    if '.' not in host:        if proxy_settings['exclude_simple']:            return True     hostIP = None    try:        hostIP = int(IPv4Address(hostonly))    except AddressValueError:        pass     for value in proxy_settings.get('exceptions', ()):        # Items in the list are strings like these: *.local, 169.254/16        if not value: continue         m = re.match(r"(\d+(?:\.\d+)*)(/\d+)?", value)        if m is not None and hostIP is not None:            base = ip2num(m.group(1))            mask = m.group(2)            if mask is None:                mask = 8 * (m.group(1).count('.') + 1)            else:                mask = int(mask[1:])             if mask < 0 or mask > 32:                # System libraries ignore invalid prefix lengths                continue             mask = 32 - mask             if (hostIP >> mask) == (base >> mask):                return True         elif fnmatch(host, value):            return True     return False  # Same as _proxy_bypass_macosx_sysconf, testable on all platformsdef _proxy_bypass_winreg_override(host, override):    """Return True if the host should bypass the proxy server.     The proxy override list is obtained from the Windows    Internet settings proxy override registry value.     An example of a proxy override value is:    "www.example.com;*.example.net; 192.168.0.1"    """    from fnmatch import fnmatch     host, _ = _splitport(host)    proxy_override = override.split(';')    for test in proxy_override:        test = test.strip()        # "<local>" should bypass the proxy server for all intranet addresses        if test == '<local>':            if '.' not in host:                return True        elif fnmatch(host, test):            return True    return False  if sys.platform == 'darwin':    from _scproxy import _get_proxy_settings, _get_proxies     def proxy_bypass_macosx_sysconf(host):        proxy_settings = _get_proxy_settings()        return _proxy_bypass_macosx_sysconf(host, proxy_settings)     def getproxies_macosx_sysconf():        """Return a dictionary of scheme -> proxy server URL mappings.         This function uses the MacOSX framework SystemConfiguration        to fetch the proxy information.        """        return _get_proxies()       def proxy_bypass(host):        """Return True, if host should be bypassed.         Checks proxy settings gathered from the environment, if specified,        or from the MacOSX framework SystemConfiguration.         """        proxies = getproxies_environment()        if proxies:            return proxy_bypass_environment(host, proxies)        else:            return proxy_bypass_macosx_sysconf(host)     def getproxies():        return getproxies_environment() or getproxies_macosx_sysconf()  elif os.name == 'nt':    def getproxies_registry():        """Return a dictionary of scheme -> proxy server URL mappings.         Win32 uses the registry to store proxies.         """        proxies = {}        try:            import winreg        except ImportError:            # Std module, so should be around - but you never know!            return proxies        try:            internetSettings = winreg.OpenKey(winreg.HKEY_CURRENT_USER,                r'Software\Microsoft\Windows\CurrentVersion\Internet Settings')            proxyEnable = winreg.QueryValueEx(internetSettings,                                               'ProxyEnable')[0]            if proxyEnable:                # Returned as Unicode but problems if not converted to ASCII                proxyServer = str(winreg.QueryValueEx(internetSettings,                                                       'ProxyServer')[0])                if '=' not in proxyServer and ';' not in proxyServer:                    # Use one setting for all protocols.                    proxyServer = 'http={0};https={0};ftp={0}'.format(proxyServer)                for p in proxyServer.split(';'):                    protocol, address = p.split('=', 1)                    # See if address has a type:// prefix                    if not re.match('(?:[^/:]+)://', address):                        # Add type:// prefix to address without specifying type                        if protocol in ('http', 'https', 'ftp'):                            # The default proxy type of Windows is HTTP                            address = 'http://' + address                        elif protocol == 'socks':                            address = 'socks://' + address                    proxies[protocol] = address                # Use SOCKS proxy for HTTP(S) protocols                if proxies.get('socks'):                    # The default SOCKS proxy type of Windows is SOCKS4                    address = re.sub(r'^socks://', 'socks4://', proxies['socks'])                    proxies['http'] = proxies.get('http') or address                    proxies['https'] = proxies.get('https') or address            internetSettings.Close()        except (OSError, ValueError, TypeError):            # Either registry key not found etc, or the value in an            # unexpected format.            # proxies already set up to be empty so nothing to do            pass        return proxies     def getproxies():        """Return a dictionary of scheme -> proxy server URL mappings.         Returns settings gathered from the environment, if specified,        or the registry.         """        return getproxies_environment() or getproxies_registry()     def proxy_bypass_registry(host):        try:            import winreg        except ImportError:            # Std modules, so should be around - but you never know!            return False        try:            internetSettings = winreg.OpenKey(winreg.HKEY_CURRENT_USER,                r'Software\Microsoft\Windows\CurrentVersion\Internet Settings')            proxyEnable = winreg.QueryValueEx(internetSettings,                                               'ProxyEnable')[0]            proxyOverride = str(winreg.QueryValueEx(internetSettings,                                                     'ProxyOverride')[0])            # ^^^^ Returned as Unicode but problems if not converted to ASCII        except OSError:            return False        if not proxyEnable or not proxyOverride:            return False        return _proxy_bypass_winreg_override(host, proxyOverride)     def proxy_bypass(host):        """Return True, if host should be bypassed.         Checks proxy settings gathered from the environment, if specified,        or the registry.         """        proxies = getproxies_environment()        if proxies:            return proxy_bypass_environment(host, proxies)        else:            return proxy_bypass_registry(host) else:    # By default use environment variables    getproxies = getproxies_environment    proxy_bypass = proxy_bypass_environment