text: r"""HTTP/1.1 client library
  
  <intro stuff goes here>
  <other stuff, too>
  
  HTTPConnection goes through a number of "states", which define when a client
  may legally make another request or fetch the response for a particular
  request. This diagram details these state transitions:
  
      (null)
        |
        | HTTPConnection()
        v
      Idle
        |
        | putrequest()
        v
      Request-started
        |
        | ( putheader() )*  endheaders()
        v
      Request-sent
        |\_____________________________
        |                              | getresponse() raises
        | response = getresponse()     | ConnectionError
        v                              v
      Unread-response                Idle
      [Response-headers-read]
        |\____________________
        |                     |
        | response.read()     | putrequest()
        v                     v
      Idle                  Req-started-unread-response
                       ______/|
                     /        |
     response.read() |        | ( putheader() )*  endheaders()
                     v        v
         Request-started    Req-sent-unread-response
                              |
                              | response.read()
                              v
                            Request-sent
  
  This diagram presents the following rules:
    -- a second request may not be started until {response-headers-read}
    -- a response [object] cannot be retrieved until {request-sent}
    -- there is no differentiation between an unread response body and a
       partially read response body
  
  Note: this enforcement is applied by the HTTPConnection class. The
        HTTPResponse class does not enforce this state machine, which
        implies sophisticated clients may accelerate the request/response
        pipeline. Caution should be taken, though: accelerating the states
        beyond the above pattern may imply knowledge of the server's
        connection-close behavior for certain requests. For example, it
        is impossible to tell whether the server will close the connection
        UNTIL the response headers have been read; this means that further
        requests cannot be placed into the pipeline until it is known that
        the server will NOT be closing the connection.
  
  Logical State                  __state            __response
  -------------                  -------            ----------
  Idle                           _CS_IDLE           None
  Request-started                _CS_REQ_STARTED    None
  Request-sent                   _CS_REQ_SENT       None
  Unread-response                _CS_IDLE           <response_class>
  Req-started-unread-response    _CS_REQ_STARTED    <response_class>
  Req-sent-unread-response       _CS_REQ_SENT       <response_class>
  """
  
  import email.parser
  import email.message
  import http
  import io
  import re
  import socket
  import collections.abc
  from urllib.parse import urlsplit
  
  # HTTPMessage, parse_headers(), and the HTTP status code constants are
  # intentionally omitted for simplicity
  __all__ = ["HTTPResponse", "HTTPConnection",
             "HTTPException", "NotConnected", "UnknownProtocol",
             "UnknownTransferEncoding", "UnimplementedFileMode",
             "IncompleteRead", "InvalidURL", "ImproperConnectionState",
             "CannotSendRequest", "CannotSendHeader", "ResponseNotReady",
             "BadStatusLine", "LineTooLong", "RemoteDisconnected", "error",
             "responses"]
  
  HTTP_PORT = 80
  HTTPS_PORT = 443
  
  _UNKNOWN = 'UNKNOWN'
  
  # connection states
  _CS_IDLE = 'Idle'
  _CS_REQ_STARTED = 'Request-started'
  _CS_REQ_SENT = 'Request-sent'
  
  
  # hack to maintain backwards compatibility
  globals().update(http.HTTPStatus.__members__)
  
  # another hack to maintain backwards compatibility
  # Mapping status codes to official W3C names
  responses = {v: v.phrase for v in http.HTTPStatus.__members__.values()}
  
  # maximal line length when calling readline().
  _MAXLINE = 65536
  _MAXHEADERS = 100
  
  # Header name/value ABNF (http://tools.ietf.org/html/rfc7230#section-3.2)
  #
  # VCHAR          = %x21-7E
  # obs-text       = %x80-FF
  # header-field   = field-name ":" OWS field-value OWS
  # field-name     = token
  # field-value    = *( field-content / obs-fold )
  # field-content  = field-vchar [ 1*( SP / HTAB ) field-vchar ]
  # field-vchar    = VCHAR / obs-text
  #
  # obs-fold       = CRLF 1*( SP / HTAB )
  #                ; obsolete line folding
  #                ; see Section 3.2.4
  
  # token          = 1*tchar
  #
  # tchar          = "!" / "#" / "$" / "%" / "&" / "'" / "*"
  #                / "+" / "-" / "." / "^" / "_" / "`" / "|" / "~"
  #                / DIGIT / ALPHA
  #                ; any VCHAR, except delimiters
  #
  # VCHAR defined in http://tools.ietf.org/html/rfc5234#appendix-B.1
  
  # the patterns for both name and value are more lenient than RFC
  # definitions to allow for backwards compatibility
  _is_legal_header_name = re.compile(rb'[^:\s][^:\r\n]*').fullmatch
  _is_illegal_header_value = re.compile(rb'\n(?![ \t])|\r(?![ \t\n])').search
  
  # These characters are not allowed within HTTP URL paths.
  #  See https://tools.ietf.org/html/rfc3986#section-3.3 and the
  #  https://tools.ietf.org/html/rfc3986#appendix-A pchar definition.
  # Prevents CVE-2019-9740.  Includes control characters such as \r\n.
  # We don't restrict chars above \x7f as putrequest() limits us to ASCII.
  _contains_disallowed_url_pchar_re = re.compile('[\x00-\x20\x7f]')
  # Arguably only these _should_ allowed:
  #  _is_allowed_url_pchars_re = re.compile(r"^[/!$&'()*+,;=:@%a-zA-Z0-9._~-]+$")
  # We are more lenient for assumed real world compatibility purposes.
  
  # These characters are not allowed within HTTP method names
  # to prevent http header injection.
  _contains_disallowed_method_pchar_re = re.compile('[\x00-\x1f]')
  
  # We always set the Content-Length header for these methods because some
  # servers will otherwise respond with a 411
  _METHODS_EXPECTING_BODY = {'PATCH', 'POST', 'PUT'}
  
  
  def _encode(data, name='data'):
      """Call data.encode("latin-1") but show a better error message."""
      try:
          return data.encode("latin-1")
      except UnicodeEncodeError as err:
          raise UnicodeEncodeError(
              err.encoding,
              err.object,
              err.start,
              err.end,
              "%s (%.20r) is not valid Latin-1. Use %s.encode('utf-8') "
              "if you want to send it encoded in UTF-8." %
              (name.title(), data[err.start:err.end], name)) from None
  
  
  class HTTPMessage(email.message.Message):
      # XXX The only usage of this method is in
      # http.server.CGIHTTPRequestHandler.  Maybe move the code there so
      # that it doesn't need to be part of the public API.  The API has
      # never been defined so this could cause backwards compatibility
      # issues.
  
      def getallmatchingheaders(self, name):
          """Find all header lines matching a given header name.
  
          Look through the list of headers and find all lines matching a given
          header name (and their continuation lines).  A list of the lines is
          returned, without interpretation.  If the header does not occur, an
          empty list is returned.  If the header occurs multiple times, all
          occurrences are returned.  Case is not important in the header name.
  
          """
          name = name.lower() + ':'
          n = len(name)
          lst = []
          hit = 0
          for line in self.keys():
              if line[:n].lower() == name:
                  hit = 1
              elif not line[:1].isspace():
                  hit = 0
              if hit:
                  lst.append(line)
          return lst
  
  def parse_headers(fp, _class=HTTPMessage):
      """Parses only RFC2822 headers from a file pointer.
  
      email Parser wants to see strings rather than bytes.
      But a TextIOWrapper around self.rfile would buffer too many bytes
      from the stream, bytes which we later need to read as bytes.
      So we read the correct bytes here, as bytes, for email Parser
      to parse.
  
      """
      headers = []
      while True:
          line = fp.readline(_MAXLINE + 1)
          if len(line) > _MAXLINE:
              raise LineTooLong("header line")
          headers.append(line)
          if len(headers) > _MAXHEADERS:
              raise HTTPException("got more than %d headers" % _MAXHEADERS)
          if line in (b'\r\n', b'\n', b''):
              break
      hstring = b''.join(headers).decode('iso-8859-1')
      return email.parser.Parser(_class=_class).parsestr(hstring)
  
  
  class HTTPResponse(io.BufferedIOBase):
  
      # See RFC 2616 sec 19.6 and RFC 1945 sec 6 for details.
  
      # The bytes from the socket object are iso-8859-1 strings.
      # See RFC 2616 sec 2.2 which notes an exception for MIME-encoded
      # text following RFC 2047.  The basic status line parsing only
      # accepts iso-8859-1.
  
      def __init__(self, sock, debuglevel=0, method=None, url=None):
          # If the response includes a content-length header, we need to
          # make sure that the client doesn't read more than the
          # specified number of bytes.  If it does, it will block until
          # the server times out and closes the connection.  This will
          # happen if a self.fp.read() is done (without a size) whether
          # self.fp is buffered or not.  So, no self.fp.read() by
          # clients unless they know what they are doing.
          self.fp = sock.makefile("rb")
          self.debuglevel = debuglevel
          self._method = method
  
          # The HTTPResponse object is returned via urllib.  The clients
          # of http and urllib expect different attributes for the
          # headers.  headers is used here and supports urllib.  msg is
          # provided as a backwards compatibility layer for http
          # clients.
  
          self.headers = self.msg = None
  
          # from the Status-Line of the response
          self.version = _UNKNOWN # HTTP-Version
          self.status = _UNKNOWN  # Status-Code
          self.reason = _UNKNOWN  # Reason-Phrase
  
          self.chunked = _UNKNOWN         # is "chunked" being used?
          self.chunk_left = _UNKNOWN      # bytes left to read in current chunk
          self.length = _UNKNOWN          # number of bytes left in response
          self.will_close = _UNKNOWN      # conn will close at end of response
  
      def _read_status(self):
          line = str(self.fp.readline(_MAXLINE + 1), "iso-8859-1")
          if len(line) > _MAXLINE:
              raise LineTooLong("status line")
          if self.debuglevel > 0:
              print("reply:", repr(line))
          if not line:
              # Presumably, the server closed the connection before
              # sending a valid response.
              raise RemoteDisconnected("Remote end closed connection without"
                                       " response")
          try:
              version, status, reason = line.split(None, 2)
          except ValueError:
              try:
                  version, status = line.split(None, 1)
                  reason = ""
              except ValueError:
                  # empty version will cause next test to fail.
                  version = ""
          if not version.startswith("HTTP/"):
              self._close_conn()
              raise BadStatusLine(line)
  
          # The status code is a three-digit number
          try:
              status = int(status)
              if status < 100 or status > 999:
                  raise BadStatusLine(line)
          except ValueError:
              raise BadStatusLine(line)
          return version, status, reason
  
      def begin(self):
          if self.headers is not None:
              # we've already started reading the response
              return
  
          # read until we get a non-100 response
          while True:
              version, status, reason = self._read_status()
              if status != CONTINUE:
                  break
              # skip the header from the 100 response
              while True:
                  skip = self.fp.readline(_MAXLINE + 1)
                  if len(skip) > _MAXLINE:
                      raise LineTooLong("header line")
                  skip = skip.strip()
                  if not skip:
                      break
                  if self.debuglevel > 0:
                      print("header:", skip)
  
          self.code = self.status = status
          self.reason = reason.strip()
          if version in ("HTTP/1.0", "HTTP/0.9"):
              # Some servers might still return "0.9", treat it as 1.0 anyway
              self.version = 10
          elif version.startswith("HTTP/1."):
              self.version = 11   # use HTTP/1.1 code for HTTP/1.x where x>=1
          else:
              raise UnknownProtocol(version)
  
          self.headers = self.msg = parse_headers(self.fp)
  
          if self.debuglevel > 0:
              for hdr, val in self.headers.items():
                  print("header:", hdr + ":", val)
  
          # are we using the chunked-style of transfer encoding?
          tr_enc = self.headers.get("transfer-encoding")
          if tr_enc and tr_enc.lower() == "chunked":
              self.chunked = True
              self.chunk_left = None
          else:
              self.chunked = False
  
          # will the connection close at the end of the response?
          self.will_close = self._check_close()
  
          # do we have a Content-Length?
          # NOTE: RFC 2616, S4.4, #3 says we ignore this if tr_enc is "chunked"
          self.length = None
          length = self.headers.get("content-length")
  
           # are we using the chunked-style of transfer encoding?
          tr_enc = self.headers.get("transfer-encoding")
          if length and not self.chunked:
              try:
                  self.length = int(length)
              except ValueError:
                  self.length = None
              else:
                  if self.length < 0:  # ignore nonsensical negative lengths
                      self.length = None
          else:
              self.length = None
  
          # does the body have a fixed length? (of zero)
          if (status == NO_CONTENT or status == NOT_MODIFIED or
              100 <= status < 200 or      # 1xx codes
              self._method == "HEAD"):
              self.length = 0
  
          # if the connection remains open, and we aren't using chunked, and
          # a content-length was not provided, then assume that the connection
          # WILL close.
          if (not self.will_close and
              not self.chunked and
              self.length is None):
              self.will_close = True
  
      def _check_close(self):
          conn = self.headers.get("connection")
          if self.version == 11:
              # An HTTP/1.1 proxy is assumed to stay open unless
              # explicitly closed.
              if conn and "close" in conn.lower():
                  return True
              return False
  
          # Some HTTP/1.0 implementations have support for persistent
          # connections, using rules different than HTTP/1.1.
  
          # For older HTTP, Keep-Alive indicates persistent connection.
          if self.headers.get("keep-alive"):
              return False
  
          # At least Akamai returns a "Connection: Keep-Alive" header,
          # which was supposed to be sent by the client.
          if conn and "keep-alive" in conn.lower():
              return False
  
          # Proxy-Connection is a netscape hack.
          pconn = self.headers.get("proxy-connection")
          if pconn and "keep-alive" in pconn.lower():
              return False
  
          # otherwise, assume it will close
          return True
  
      def _close_conn(self):
          fp = self.fp
          self.fp = None
          fp.close()
  
      def close(self):
          try:
              super().close() # set "closed" flag
          finally:
              if self.fp:
                  self._close_conn()
  
      # These implementations are for the benefit of io.BufferedReader.
  
      # XXX This class should probably be revised to act more like
      # the "raw stream" that BufferedReader expects.
  
      def flush(self):
          super().flush()
          if self.fp:
              self.fp.flush()
  
      def readable(self):
          """Always returns True"""
          return True
  
      # End of "raw stream" methods
  
      def isclosed(self):
          """True if the connection is closed."""
          # NOTE: it is possible that we will not ever call self.close(). This
          #       case occurs when will_close is TRUE, length is None, and we
          #       read up to the last byte, but NOT past it.
          #
          # IMPLIES: if will_close is FALSE, then self.close() will ALWAYS be
          #          called, meaning self.isclosed() is meaningful.
          return self.fp is None
  
      def read(self, amt=None):
          if self.fp is None:
              return b""
  
          if self._method == "HEAD":
              self._close_conn()
              return b""
  
          if self.chunked:
              return self._read_chunked(amt)
  
          if amt is not None:
              if self.length is not None and amt > self.length:
                  # clip the read to the "end of response"
                  amt = self.length
              s = self.fp.read(amt)
              if not s and amt:
                  # Ideally, we would raise IncompleteRead if the content-length
                  # wasn't satisfied, but it might break compatibility.
                  self._close_conn()
              elif self.length is not None:
                  self.length -= len(s)
                  if not self.length:
                      self._close_conn()
              return s
          else:
              # Amount is not given (unbounded read) so we must check self.length
              if self.length is None:
                  s = self.fp.read()
              else:
                  try:
                      s = self._safe_read(self.length)
                  except IncompleteRead:
                      self._close_conn()
                      raise
                  self.length = 0
              self._close_conn()        # we read everything
              return s
  
      def readinto(self, b):
          """Read up to len(b) bytes into bytearray b and return the number
          of bytes read.
          """
  
          if self.fp is None:
              return 0
  
          if self._method == "HEAD":
              self._close_conn()
              return 0
  
          if self.chunked:
              return self._readinto_chunked(b)
  
          if self.length is not None:
              if len(b) > self.length:
                  # clip the read to the "end of response"
                  b = memoryview(b)[0:self.length]
  
          # we do not use _safe_read() here because this may be a .will_close
          # connection, and the user is reading more bytes than will be provided
          # (for example, reading in 1k chunks)
          n = self.fp.readinto(b)
          if not n and b:
              # Ideally, we would raise IncompleteRead if the content-length
              # wasn't satisfied, but it might break compatibility.
              self._close_conn()
          elif self.length is not None:
              self.length -= n
              if not self.length:
                  self._close_conn()
          return n
  
      def _read_next_chunk_size(self):
          # Read the next chunk size from the file
          line = self.fp.readline(_MAXLINE + 1)
          if len(line) > _MAXLINE:
              raise LineTooLong("chunk size")
          i = line.find(b";")
          if i >= 0:
              line = line[:i] # strip chunk-extensions
          try:
              return int(line, 16)
          except ValueError:
              # close the connection as protocol synchronisation is
              # probably lost
              self._close_conn()
              raise
  
      def _read_and_discard_trailer(self):
          # read and discard trailer up to the CRLF terminator
          ### note: we shouldn't have any trailers!
          while True:
              line = self.fp.readline(_MAXLINE + 1)
              if len(line) > _MAXLINE:
                  raise LineTooLong("trailer line")
              if not line:
                  # a vanishingly small number of sites EOF without
                  # sending the trailer
                  break
              if line in (b'\r\n', b'\n', b''):
                  break
  
      def _get_chunk_left(self):
          # return self.chunk_left, reading a new chunk if necessary.
          # chunk_left == 0: at the end of the current chunk, need to close it
          # chunk_left == None: No current chunk, should read next.
          # This function returns non-zero or None if the last chunk has
          # been read.
          chunk_left = self.chunk_left
          if not chunk_left: # Can be 0 or None
              if chunk_left is not None:
                  # We are at the end of chunk, discard chunk end
                  self._safe_read(2)  # toss the CRLF at the end of the chunk
              try:
                  chunk_left = self._read_next_chunk_size()
              except ValueError:
                  raise IncompleteRead(b'')
              if chunk_left == 0:
                  # last chunk: 1*("0") [ chunk-extension ] CRLF
                  self._read_and_discard_trailer()
                  # we read everything; close the "file"
                  self._close_conn()
                  chunk_left = None
              self.chunk_left = chunk_left
          return chunk_left
  
      def _read_chunked(self, amt=None):
          assert self.chunked != _UNKNOWN
          value = []
          try:
              while True:
                  chunk_left = self._get_chunk_left()
                  if chunk_left is None:
                      break
  
                  if amt is not None and amt <= chunk_left:
                      value.append(self._safe_read(amt))
                      self.chunk_left = chunk_left - amt
                      break
  
                  value.append(self._safe_read(chunk_left))
                  if amt is not None:
                      amt -= chunk_left
                  self.chunk_left = 0
              return b''.join(value)
          except IncompleteRead:
              raise IncompleteRead(b''.join(value))
  
      def _readinto_chunked(self, b):
          assert self.chunked != _UNKNOWN
          total_bytes = 0
          mvb = memoryview(b)
          try:
              while True:
                  chunk_left = self._get_chunk_left()
                  if chunk_left is None:
                      return total_bytes
  
                  if len(mvb) <= chunk_left:
                      n = self._safe_readinto(mvb)
                      self.chunk_left = chunk_left - n
                      return total_bytes + n
  
                  temp_mvb = mvb[:chunk_left]
                  n = self._safe_readinto(temp_mvb)
                  mvb = mvb[n:]
                  total_bytes += n
                  self.chunk_left = 0
  
          except IncompleteRead:
              raise IncompleteRead(bytes(b[0:total_bytes]))
  
      def _safe_read(self, amt):
          """Read the number of bytes requested.
  
          This function should be used when <amt> bytes "should" be present for
          reading. If the bytes are truly not available (due to EOF), then the
          IncompleteRead exception can be used to detect the problem.
          """
          data = self.fp.read(amt)
          if len(data) < amt:
              raise IncompleteRead(data, amt-len(data))
          return data
  
      def _safe_readinto(self, b):
          """Same as _safe_read, but for reading into a buffer."""
          amt = len(b)
          n = self.fp.readinto(b)
          if n < amt:
              raise IncompleteRead(bytes(b[:n]), amt-n)
          return n
  
      def read1(self, n=-1):
          """Read with at most one underlying system call.  If at least one
          byte is buffered, return that instead.
          """
          if self.fp is None or self._method == "HEAD":
              return b""
          if self.chunked:
              return self._read1_chunked(n)
          if self.length is not None and (n < 0 or n > self.length):
              n = self.length
          result = self.fp.read1(n)
          if not result and n:
              self._close_conn()
          elif self.length is not None:
              self.length -= len(result)
          return result
  
      def peek(self, n=-1):
          # Having this enables IOBase.readline() to read more than one
          # byte at a time
          if self.fp is None or self._method == "HEAD":
              return b""
          if self.chunked:
              return self._peek_chunked(n)
          return self.fp.peek(n)
  
      def readline(self, limit=-1):
          if self.fp is None or self._method == "HEAD":
              return b""
          if self.chunked:
              # Fallback to IOBase readline which uses peek() and read()
              return super().readline(limit)
          if self.length is not None and (limit < 0 or limit > self.length):
              limit = self.length
          result = self.fp.readline(limit)
          if not result and limit:
              self._close_conn()
          elif self.length is not None:
              self.length -= len(result)
          return result
  
      def _read1_chunked(self, n):
          # Strictly speaking, _get_chunk_left() may cause more than one read,
          # but that is ok, since that is to satisfy the chunked protocol.
          chunk_left = self._get_chunk_left()
          if chunk_left is None or n == 0:
              return b''
          if not (0 <= n <= chunk_left):
              n = chunk_left # if n is negative or larger than chunk_left
          read = self.fp.read1(n)
          self.chunk_left -= len(read)
          if not read:
              raise IncompleteRead(b"")
          return read
  
      def _peek_chunked(self, n):
          # Strictly speaking, _get_chunk_left() may cause more than one read,
          # but that is ok, since that is to satisfy the chunked protocol.
          try:
              chunk_left = self._get_chunk_left()
          except IncompleteRead:
              return b'' # peek doesn't worry about protocol
          if chunk_left is None:
              return b'' # eof
          # peek is allowed to return more than requested.  Just request the
          # entire chunk, and truncate what we get.
          return self.fp.peek(chunk_left)[:chunk_left]
  
      def fileno(self):
          return self.fp.fileno()
  
      def getheader(self, name, default=None):
          '''Returns the value of the header matching *name*.
  
          If there are multiple matching headers, the values are
          combined into a single string separated by commas and spaces.
  
          If no matching header is found, returns *default* or None if
          the *default* is not specified.
  
          If the headers are unknown, raises http.client.ResponseNotReady.
  
          '''
          if self.headers is None:
              raise ResponseNotReady()
          headers = self.headers.get_all(name) or default
          if isinstance(headers, str) or not hasattr(headers, '__iter__'):
              return headers
          else:
              return ', '.join(headers)
  
      def getheaders(self):
          """Return list of (header, value) tuples."""
          if self.headers is None:
              raise ResponseNotReady()
          return list(self.headers.items())
  
      # We override IOBase.__iter__ so that it doesn't check for closed-ness
  
      def __iter__(self):
          return self
  
      # For compatibility with old-style urllib responses.
  
      def info(self):
          '''Returns an instance of the class mimetools.Message containing
          meta-information associated with the URL.
  
          When the method is HTTP, these headers are those returned by
          the server at the head of the retrieved HTML page (including
          Content-Length and Content-Type).
  
          When the method is FTP, a Content-Length header will be
          present if (as is now usual) the server passed back a file
          length in response to the FTP retrieval request. A
          Content-Type header will be present if the MIME type can be
          guessed.
  
          When the method is local-file, returned headers will include
          a Date representing the file's last-modified time, a
          Content-Length giving file size, and a Content-Type
          containing a guess at the file's type. See also the
          description of the mimetools module.
  
          '''
          return self.headers
  
      def geturl(self):
          '''Return the real URL of the page.
  
          In some cases, the HTTP server redirects a client to another
          URL. The urlopen() function handles this transparently, but in
          some cases the caller needs to know which URL the client was
          redirected to. The geturl() method can be used to get at this
          redirected URL.
  
          '''
          return self.url
  
      def getcode(self):
          '''Return the HTTP status code that was sent with the response,
          or None if the URL is not an HTTP URL.
  
          '''
          return self.status
  
  class HTTPConnection:
  
      _http_vsn = 11
      _http_vsn_str = 'HTTP/1.1'
  
      response_class = HTTPResponse
      default_port = HTTP_PORT
      auto_open = 1
      debuglevel = 0
  
      @staticmethod
      def _is_textIO(stream):
          """Test whether a file-like object is a text or a binary stream.
          """
          return isinstance(stream, io.TextIOBase)
  
      @staticmethod
      def _get_content_length(body, method):
          """Get the content-length based on the body.
  
          If the body is None, we set Content-Length: 0 for methods that expect
          a body (RFC 7230, Section 3.3.2). We also set the Content-Length for
          any method if the body is a str or bytes-like object and not a file.
          """
          if body is None:
              # do an explicit check for not None here to distinguish
              # between unset and set but empty
              if method.upper() in _METHODS_EXPECTING_BODY:
                  return 0
              else:
                  return None
  
          if hasattr(body, 'read'):
              # file-like object.
              return None
  
          try:
              # does it implement the buffer protocol (bytes, bytearray, array)?
              mv = memoryview(body)
              return mv.nbytes
          except TypeError:
              pass
  
          if isinstance(body, str):
              return len(body)
  
          return None
  
      def __init__(self, host, port=None, timeout=socket._GLOBAL_DEFAULT_TIMEOUT,
                   source_address=None, blocksize=8192):
          self.timeout = timeout
          self.source_address = source_address
          self.blocksize = blocksize
          self.sock = None
          self._buffer = []
          self.__response = None
          self.__state = _CS_IDLE
          self._method = None
          self._tunnel_host = None
          self._tunnel_port = None
          self._tunnel_headers = {}
  
          (self.host, self.port) = self._get_hostport(host, port)
  
          self._validate_host(self.host)
  
          # This is stored as an instance variable to allow unit
          # tests to replace it with a suitable mockup
          self._create_connection = socket.create_connection
  
      def set_tunnel(self, host, port=None, headers=None):
          """Set up host and port for HTTP CONNECT tunnelling.
  
          In a connection that uses HTTP CONNECT tunneling, the host passed to the
          constructor is used as a proxy server that relays all communication to
          the endpoint passed to `set_tunnel`. This done by sending an HTTP
          CONNECT request to the proxy server when the connection is established.
  
          This method must be called before the HTML connection has been
          established.
  
          The headers argument should be a mapping of extra HTTP headers to send
          with the CONNECT request.
          """
  
          if self.sock:
              raise RuntimeError("Can't set up tunnel for established connection")
  
          self._tunnel_host, self._tunnel_port = self._get_hostport(host, port)
          if headers:
              self._tunnel_headers = headers
          else:
              self._tunnel_headers.clear()
  
      def _get_hostport(self, host, port):
          if port is None:
              i = host.rfind(':')
              j = host.rfind(']')         # ipv6 addresses have [...]
              if i > j:
                  try:
                      port = int(host[i+1:])
                  except ValueError:
                      if host[i+1:] == "": # http://foo.com:/ == http://foo.com/
                          port = self.default_port
                      else:
                          raise InvalidURL("nonnumeric port: '%s'" % host[i+1:])
                  host = host[:i]
              else:
                  port = self.default_port
              if host and host[0] == '[' and host[-1] == ']':
                  host = host[1:-1]
  
          return (host, port)
  
      def set_debuglevel(self, level):
          self.debuglevel = level
  
      def _tunnel(self):
          connect_str = "CONNECT %s:%d HTTP/1.0\r\n" % (self._tunnel_host,
              self._tunnel_port)
          connect_bytes = connect_str.encode("ascii")
          self.send(connect_bytes)
          for header, value in self._tunnel_headers.items():
              header_str = "%s: %s\r\n" % (header, value)
              header_bytes = header_str.encode("latin-1")
              self.send(header_bytes)
          self.send(b'\r\n')
  
          response = self.response_class(self.sock, method=self._method)
          (version, code, message) = response._read_status()
  
          if code != http.HTTPStatus.OK:
              self.close()
              raise OSError("Tunnel connection failed: %d %s" % (code,
                                                                 message.strip()))
          while True:
              line = response.fp.readline(_MAXLINE + 1)
              if len(line) > _MAXLINE:
                  raise LineTooLong("header line")
              if not line:
                  # for sites which EOF without sending a trailer
                  break
              if line in (b'\r\n', b'\n', b''):
                  break
  
              if self.debuglevel > 0:
                  print('header:', line.decode())
  
      def connect(self):
          """Connect to the host and port specified in __init__."""
          self.sock = self._create_connection(
              (self.host,self.port), self.timeout, self.source_address)
          self.sock.setsockopt(socket.IPPROTO_TCP, socket.TCP_NODELAY, 1)
  
          if self._tunnel_host:
              self._tunnel()
  
      def close(self):
          """Close the connection to the HTTP server."""
          self.__state = _CS_IDLE
          try:
              sock = self.sock
              if sock:
                  self.sock = None
                  sock.close()   # close it manually... there may be other refs
          finally:
              response = self.__response
              if response:
                  self.__response = None
                  response.close()
  
      def send(self, data):
          """Send `data' to the server.
          ``data`` can be a string object, a bytes object, an array object, a
          file-like object that supports a .read() method, or an iterable object.
          """
  
          if self.sock is None:
              if self.auto_open:
                  self.connect()
              else:
                  raise NotConnected()
  
          if self.debuglevel > 0:
              print("send:", repr(data))
          if hasattr(data, "read") :
              if self.debuglevel > 0:
                  print("sendIng a read()able")
              encode = self._is_textIO(data)
              if encode and self.debuglevel > 0:
                  print("encoding file using iso-8859-1")
              while 1:
                  datablock = data.read(self.blocksize)
                  if not datablock:
                      break
                  if encode:
                      datablock = datablock.encode("iso-8859-1")
                  self.sock.sendall(datablock)
              return
          try:
              self.sock.sendall(data)
          except TypeError:
              if isinstance(data, collections.abc.Iterable):
                  for d in data:
                      self.sock.sendall(d)
              else:
                  raise TypeError("data should be a bytes-like object "
                                  "or an iterable, got %r" % type(data))
  
      def _output(self, s):
          """Add a line of output to the current request buffer.
  
          Assumes that the line does *not* end with \\r\\n.
          """
          self._buffer.append(s)
  
      def _read_readable(self, readable):
          if self.debuglevel > 0:
              print("sendIng a read()able")
          encode = self._is_textIO(readable)
          if encode and self.debuglevel > 0:
              print("encoding file using iso-8859-1")
          while True:
              datablock = readable.read(self.blocksize)
              if not datablock:
                  break
              if encode:
                  datablock = datablock.encode("iso-8859-1")
              yield datablock
  
      def _send_output(self, message_body=None, encode_chunked=False):
          """Send the currently buffered request and clear the buffer.
  
          Appends an extra \\r\\n to the buffer.
          A message_body may be specified, to be appended to the request.
          """
          self._buffer.extend((b"", b""))
          msg = b"\r\n".join(self._buffer)
          del self._buffer[:]
          self.send(msg)
  
          if message_body is not None:
  
              # create a consistent interface to message_body
              if hasattr(message_body, 'read'):
                  # Let file-like take precedence over byte-like.  This
                  # is needed to allow the current position of mmap'ed
                  # files to be taken into account.
                  chunks = self._read_readable(message_body)
              else:
                  try:
                      # this is solely to check to see if message_body
                      # implements the buffer API.  it /would/ be easier
                      # to capture if PyObject_CheckBuffer was exposed
                      # to Python.
                      memoryview(message_body)
                  except TypeError:
                      try:
                          chunks = iter(message_body)
                      except TypeError:
                          raise TypeError("message_body should be a bytes-like "
                                          "object or an iterable, got %r"
                                          % type(message_body))
                  else:
                      # the object implements the buffer interface and
                      # can be passed directly into socket methods
                      chunks = (message_body,)
  
              for chunk in chunks:
                  if not chunk:
                      if self.debuglevel > 0:
                          print('Zero length chunk ignored')
                      continue
  
                  if encode_chunked and self._http_vsn == 11:
                      # chunked encoding
                      chunk = f'{len(chunk):X}\r\n'.encode('ascii') + chunk \
                          + b'\r\n'
                  self.send(chunk)
  
              if encode_chunked and self._http_vsn == 11:
                  # end chunked transfer
                  self.send(b'0\r\n\r\n')
  
      def putrequest(self, method, url, skip_host=False,
                     skip_accept_encoding=False):
          """Send a request to the server.
  
          `method' specifies an HTTP request method, e.g. 'GET'.
          `url' specifies the object being requested, e.g. '/index.html'.
          `skip_host' if True does not add automatically a 'Host:' header
          `skip_accept_encoding' if True does not add automatically an
             'Accept-Encoding:' header
          """
  
          # if a prior response has been completed, then forget about it.
          if self.__response and self.__response.isclosed():
              self.__response = None
  
  
          # in certain cases, we cannot issue another request on this connection.
          # this occurs when:
          #   1) we are in the process of sending a request.   (_CS_REQ_STARTED)
          #   2) a response to a previous request has signalled that it is going
          #      to close the connection upon completion.
          #   3) the headers for the previous response have not been read, thus
          #      we cannot determine whether point (2) is true.   (_CS_REQ_SENT)
          #
          # if there is no prior response, then we can request at will.
          #
          # if point (2) is true, then we will have passed the socket to the
          # response (effectively meaning, "there is no prior response"), and
          # will open a new one when a new request is made.
          #
          # Note: if a prior response exists, then we *can* start a new request.
          #       We are not allowed to begin fetching the response to this new
          #       request, however, until that prior response is complete.
          #
          if self.__state == _CS_IDLE:
              self.__state = _CS_REQ_STARTED
          else:
              raise CannotSendRequest(self.__state)
  
          self._validate_method(method)
  
          # Save the method for use later in the response phase
          self._method = method
  
          url = url or '/'
          self._validate_path(url)
  
          request = '%s %s %s' % (method, url, self._http_vsn_str)
  
          self._output(self._encode_request(request))
  
          if self._http_vsn == 11:
              # Issue some standard headers for better HTTP/1.1 compliance
  
              if not skip_host:
                  # this header is issued *only* for HTTP/1.1
                  # connections. more specifically, this means it is
                  # only issued when the client uses the new
                  # HTTPConnection() class. backwards-compat clients
                  # will be using HTTP/1.0 and those clients may be
                  # issuing this header themselves. we should NOT issue
                  # it twice; some web servers (such as Apache) barf
                  # when they see two Host: headers
  
                  # If we need a non-standard port,include it in the
                  # header.  If the request is going through a proxy,
                  # but the host of the actual URL, not the host of the
                  # proxy.
  
                  netloc = ''
                  if url.startswith('http'):
                      nil, netloc, nil, nil, nil = urlsplit(url)
  
                  if netloc:
                      try:
                          netloc_enc = netloc.encode("ascii")
                      except UnicodeEncodeError:
                          netloc_enc = netloc.encode("idna")
                      self.putheader('Host', netloc_enc)
                  else:
                      if self._tunnel_host:
                          host = self._tunnel_host
                          port = self._tunnel_port
                      else:
                          host = self.host
                          port = self.port
  
                      try:
                          host_enc = host.encode("ascii")
                      except UnicodeEncodeError:
                          host_enc = host.encode("idna")
  
                      # As per RFC 273, IPv6 address should be wrapped with []
                      # when used as Host header
  
                      if host.find(':') >= 0:
                          host_enc = b'[' + host_enc + b']'
  
                      if port == self.default_port:
                          self.putheader('Host', host_enc)
                      else:
                          host_enc = host_enc.decode("ascii")
                          self.putheader('Host', "%s:%s" % (host_enc, port))
  
              # note: we are assuming that clients will not attempt to set these
              #       headers since *this* library must deal with the
              #       consequences. this also means that when the supporting
              #       libraries are updated to recognize other forms, then this
              #       code should be changed (removed or updated).
  
              # we only want a Content-Encoding of "identity" since we don't
              # support encodings such as x-gzip or x-deflate.
              if not skip_accept_encoding:
                  self.putheader('Accept-Encoding', 'identity')
  
              # we can accept "chunked" Transfer-Encodings, but no others
              # NOTE: no TE header implies *only* "chunked"
              #self.putheader('TE', 'chunked')
  
              # if TE is supplied in the header, then it must appear in a
              # Connection header.
              #self.putheader('Connection', 'TE')
  
          else:
              # For HTTP/1.0, the server will assume "not chunked"
              pass
  
      def _encode_request(self, request):
          # ASCII also helps prevent CVE-2019-9740.
          return request.encode('ascii')
  
      def _validate_method(self, method):
          """Validate a method name for putrequest."""
          # prevent http header injection
          match = _contains_disallowed_method_pchar_re.search(method)
          if match:
              raise ValueError(
                      f"method can't contain control characters. {method!r} "
                      f"(found at least {match.group()!r})")
  
      def _validate_path(self, url):
          """Validate a url for putrequest."""
          # Prevent CVE-2019-9740.
          match = _contains_disallowed_url_pchar_re.search(url)
          if match:
              raise InvalidURL(f"URL can't contain control characters. {url!r} "
                               f"(found at least {match.group()!r})")
  
      def _validate_host(self, host):
          """Validate a host so it doesn't contain control characters."""
          # Prevent CVE-2019-18348.
          match = _contains_disallowed_url_pchar_re.search(host)
          if match:
              raise InvalidURL(f"URL can't contain control characters. {host!r} "
                               f"(found at least {match.group()!r})")
  
      def putheader(self, header, *values):
          """Send a request header line to the server.
  
          For example: h.putheader('Accept', 'text/html')
          """
          if self.__state != _CS_REQ_STARTED:
              raise CannotSendHeader()
  
          if hasattr(header, 'encode'):
              header = header.encode('ascii')
  
          if not _is_legal_header_name(header):
              raise ValueError('Invalid header name %r' % (header,))
  
          values = list(values)
          for i, one_value in enumerate(values):
              if hasattr(one_value, 'encode'):
                  values[i] = one_value.encode('latin-1')
              elif isinstance(one_value, int):
                  values[i] = str(one_value).encode('ascii')
  
              if _is_illegal_header_value(values[i]):
                  raise ValueError('Invalid header value %r' % (values[i],))
  
          value = b'\r\n\t'.join(values)
          header = header + b': ' + value
          self._output(header)
  
      def endheaders(self, message_body=None, *, encode_chunked=False):
          """Indicate that the last header line has been sent to the server.
  
          This method sends the request to the server.  The optional message_body
          argument can be used to pass a message body associated with the
          request.
          """
          if self.__state == _CS_REQ_STARTED:
              self.__state = _CS_REQ_SENT
          else:
              raise CannotSendHeader()
          self._send_output(message_body, encode_chunked=encode_chunked)
  
      def request(self, method, url, body=None, headers={}, *,
                  encode_chunked=False):
          """Send a complete request to the server."""
          self._send_request(method, url, body, headers, encode_chunked)
  
      def _send_request(self, method, url, body, headers, encode_chunked):
          # Honor explicitly requested Host: and Accept-Encoding: headers.
          header_names = frozenset(k.lower() for k in headers)
          skips = {}
          if 'host' in header_names:
              skips['skip_host'] = 1
          if 'accept-encoding' in header_names:
              skips['skip_accept_encoding'] = 1
  
          self.putrequest(method, url, **skips)
  
          # chunked encoding will happen if HTTP/1.1 is used and either
          # the caller passes encode_chunked=True or the following
          # conditions hold:
          # 1. content-length has not been explicitly set
          # 2. the body is a file or iterable, but not a str or bytes-like
          # 3. Transfer-Encoding has NOT been explicitly set by the caller
  
          if 'content-length' not in header_names:
              # only chunk body if not explicitly set for backwards
              # compatibility, assuming the client code is already handling the
              # chunking
              if 'transfer-encoding' not in header_names:
                  # if content-length cannot be automatically determined, fall
                  # back to chunked encoding
                  encode_chunked = False
                  content_length = self._get_content_length(body, method)
                  if content_length is None:
                      if body is not None:
                          if self.debuglevel > 0:
                              print('Unable to determine size of %r' % body)
                          encode_chunked = True
                          self.putheader('Transfer-Encoding', 'chunked')
                  else:
                      self.putheader('Content-Length', str(content_length))
          else:
              encode_chunked = False
  
          for hdr, value in headers.items():
              self.putheader(hdr, value)
          if isinstance(body, str):
              # RFC 2616 Section 3.7.1 says that text default has a
              # default charset of iso-8859-1.
              body = _encode(body, 'body')
          self.endheaders(body, encode_chunked=encode_chunked)
  
      def getresponse(self):
          """Get the response from the server.
  
          If the HTTPConnection is in the correct state, returns an
          instance of HTTPResponse or of whatever object is returned by
          the response_class variable.
  
          If a request has not been sent or if a previous response has
          not be handled, ResponseNotReady is raised.  If the HTTP
          response indicates that the connection should be closed, then
          it will be closed before the response is returned.  When the
          connection is closed, the underlying socket is closed.
          """
  
          # if a prior response has been completed, then forget about it.
          if self.__response and self.__response.isclosed():
              self.__response = None
  
          # if a prior response exists, then it must be completed (otherwise, we
          # cannot read this response's header to determine the connection-close
          # behavior)
          #
          # note: if a prior response existed, but was connection-close, then the
          # socket and response were made independent of this HTTPConnection
          # object since a new request requires that we open a whole new
          # connection
          #
          # this means the prior response had one of two states:
          #   1) will_close: this connection was reset and the prior socket and
          #                  response operate independently
          #   2) persistent: the response was retained and we await its
          #                  isclosed() status to become true.
          #
          if self.__state != _CS_REQ_SENT or self.__response:
              raise ResponseNotReady(self.__state)
  
          if self.debuglevel > 0:
              response = self.response_class(self.sock, self.debuglevel,
                                             method=self._method)
          else:
              response = self.response_class(self.sock, method=self._method)
  
          try:
              try:
                  response.begin()
              except ConnectionError:
                  self.close()
                  raise
              assert response.will_close != _UNKNOWN
              self.__state = _CS_IDLE
  
              if response.will_close:
                  # this effectively passes the connection to the response
                  self.close()
              else:
                  # remember this, so we can tell when it is complete
                  self.__response = response
  
              return response
          except:
              response.close()
              raise
  
  try:
      import ssl
  except ImportError:
      pass
  else:
      class HTTPSConnection(HTTPConnection):
          "This class allows communication via SSL."
  
          default_port = HTTPS_PORT
  
          # XXX Should key_file and cert_file be deprecated in favour of context?
  
          def __init__(self, host, port=None, key_file=None, cert_file=None,
                       timeout=socket._GLOBAL_DEFAULT_TIMEOUT,
                       source_address=None, *, context=None,
                       check_hostname=None, blocksize=8192):
              super(HTTPSConnection, self).__init__(host, port, timeout,
                                                    source_address,
                                                    blocksize=blocksize)
              if (key_file is not None or cert_file is not None or
                          check_hostname is not None):
                  import warnings
                  warnings.warn("key_file, cert_file and check_hostname are "
                                "deprecated, use a custom context instead.",
                                DeprecationWarning, 2)
              self.key_file = key_file
              self.cert_file = cert_file
              if context is None:
                  context = ssl._create_default_https_context()
                  # enable PHA for TLS 1.3 connections if available
                  if context.post_handshake_auth is not None:
                      context.post_handshake_auth = True
              will_verify = context.verify_mode != ssl.CERT_NONE
              if check_hostname is None:
                  check_hostname = context.check_hostname
              if check_hostname and not will_verify:
                  raise ValueError("check_hostname needs a SSL context with "
                                   "either CERT_OPTIONAL or CERT_REQUIRED")
              if key_file or cert_file:
                  context.load_cert_chain(cert_file, key_file)
                  # cert and key file means the user wants to authenticate.
                  # enable TLS 1.3 PHA implicitly even for custom contexts.
                  if context.post_handshake_auth is not None:
                      context.post_handshake_auth = True
              self._context = context
              if check_hostname is not None:
                  self._context.check_hostname = check_hostname
  
          def connect(self):
              "Connect to a host on a given (SSL) port."
  
              super().connect()
  
              if self._tunnel_host:
                  server_hostname = self._tunnel_host
              else:
                  server_hostname = self.host
  
              self.sock = self._context.wrap_socket(self.sock,
                                                    server_hostname=server_hostname)
  
      __all__.append("HTTPSConnection")
  
  class HTTPException(Exception):
      # Subclasses that define an __init__ must call Exception.__init__
      # or define self.args.  Otherwise, str() will fail.
      pass
  
  class NotConnected(HTTPException):
      pass
  
  class InvalidURL(HTTPException):
      pass
  
  class UnknownProtocol(HTTPException):
      def __init__(self, version):
          self.args = version,
          self.version = version
  
  class UnknownTransferEncoding(HTTPException):
      pass
  
  class UnimplementedFileMode(HTTPException):
      pass
  
  class IncompleteRead(HTTPException):
      def __init__(self, partial, expected=None):
          self.args = partial,
          self.partial = partial
          self.expected = expected
      def __repr__(self):
          if self.expected is not None:
              e = ', %i more expected' % self.expected
          else:
              e = ''
          return '%s(%i bytes read%s)' % (self.__class__.__name__,
                                          len(self.partial), e)
      __str__ = object.__str__
  
  class ImproperConnectionState(HTTPException):
      pass
  
  class CannotSendRequest(ImproperConnectionState):
      pass
  
  class CannotSendHeader(ImproperConnectionState):
      pass
  
  class ResponseNotReady(ImproperConnectionState):
      pass
  
  class BadStatusLine(HTTPException):
      def __init__(self, line):
          if not line:
              line = repr(line)
          self.args = line,
          self.line = line
  
  class LineTooLong(HTTPException):
      def __init__(self, line_type):
          HTTPException.__init__(self, "got more than %d bytes when reading %s"
                                       % (_MAXLINE, line_type))
  
  class RemoteDisconnected(ConnectionResetError, BadStatusLine):
      def __init__(self, *pos, **kw):
          BadStatusLine.__init__(self, "")
          ConnectionResetError.__init__(self, *pos, **kw)
  
  # for backwards compatibility
  error = HTTPException
  