Method parse

tornado/httputil.py:297–335

Returns a dictionary from HTTP header text. >>> h = HTTPHeaders.parse("Content-Type: text/html\\r\\nContent-Length: 42\\r\\n") >>> sorted(h.items()) [('Content-Length', '42'), ('Content-Type', 'text/html')] .. versionchanged:: 5.1 Raises `HTTPInputError`

(cls, headers: str, *, _chars_are_bytes: bool = True)

    @classmethod
    def parse(cls, headers: str, *, _chars_are_bytes: bool = True) -> "HTTPHeaders":
        """Returns a dictionary from HTTP header text.

        >>> h = HTTPHeaders.parse("Content-Type: text/html\\r\\nContent-Length: 42\\r\\n")
        >>> sorted(h.items())
        [('Content-Length', '42'), ('Content-Type', 'text/html')]

        .. versionchanged:: 5.1

           Raises `HTTPInputError` on malformed headers instead of a
           mix of `KeyError`, and `ValueError`.

        """
        # _chars_are_bytes is a hack. This method is used in two places, HTTP headers (in which
        # non-ascii characters are to be interpreted as latin-1) and multipart/form-data (in which
        # they are to be interpreted as utf-8). For historical reasons, this method handled this by
        # expecting both callers to decode the headers to strings before parsing them. This wasn't a
        # problem until we started doing stricter validation of the characters allowed in HTTP
        # headers (using ABNF rules defined in terms of byte values), which inadvertently started
        # disallowing non-latin1 characters in multipart/form-data filenames.
        #
        # This method should have accepted bytes and a desired encoding, but this change is being
        # introduced in a patch release that shouldn't change the API. Instead, the _chars_are_bytes
        # flag decides whether to use HTTP-style ABNF validation (treating the string as bytes
        # smuggled through the latin1 encoding) or to accept any non-control unicode characters
        # as required by multipart/form-data. This method will change to accept bytes in a future
        # release.
        h = cls()

        start = 0
        while True:
            lf = headers.find("\n", start)
            if lf == -1:
                h.parse_line(headers[start:], _chars_are_bytes=_chars_are_bytes)
                break
            line = headers[start : lf + 1]
            start = lf + 1
            h.parse_line(line, _chars_are_bytes=_chars_are_bytes)
        return h

    # MutableMapping abstract method implementations.