python类host()的实例源码

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.headers.get(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_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)
        self.reset_retry_count()
        return response


# Return n random bytes.

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

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 is self.get_names():
                raise URLError("file:// scheme is supported only on localhost")
        else:
            return self.open_local_file(req)

    # names for the localhost

def open_local_file(self, req):
        import future.backports.email.utils as 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:
            # users shouldn't expect OSErrors coming from urlopen()
            raise URLError(exp)
        raise URLError('file not on local host')

def _safe_gethostbyname(host):
    try:
        return socket.gethostbyname(host)
    except socket.gaierror:
        return None

def connect_ftp(self, user, passwd, host, port, dirs, timeout):
        return ftpwrapper(user, passwd, host, port, dirs, timeout,
                          persistent=False)

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]