# Source code for w3lib.url

    """
    This module contains general purpose URL functions not found in the standard
    library.
    """

    from __future__ import annotations

    import base64
    import codecs
    import os
    import posixpath
    import re
    import string
    from collections.abc import Sequence
    from typing import Callable, NamedTuple, cast, overload
    from urllib.parse import _coerce_args  # type: ignore
    from urllib.parse import (
        ParseResult,
        parse_qs,
        parse_qsl,
        quote,
        unquote,
        unquote_to_bytes,
        urldefrag,
        urlencode,
        urlparse,
        urlsplit,
        urlunparse,
        urlunsplit,
    )
    from urllib.request import pathname2url, url2pathname

    from ._infra import _ASCII_TAB_OR_NEWLINE, _C0_CONTROL_OR_SPACE
    from ._types import AnyUnicodeError, StrOrBytes
    from ._url import _SPECIAL_SCHEMES
    from .util import to_unicode

    # error handling function for bytes-to-Unicode decoding errors with URLs
    def _quote_byte(error: UnicodeError) -> tuple[str, int]:
        error = cast(AnyUnicodeError, error)
        return (to_unicode(quote(error.object[error.start : error.end])), error.end)

    codecs.register_error("percentencode", _quote_byte)

    # constants from RFC 3986, Section 2.2 and 2.3
    RFC3986_GEN_DELIMS = b":/?#[]@"
    RFC3986_SUB_DELIMS = b"!$&'()*+,;="
    RFC3986_RESERVED = RFC3986_GEN_DELIMS + RFC3986_SUB_DELIMS
    RFC3986_UNRESERVED = (string.ascii_letters + string.digits + "-._~").encode("ascii")
    EXTRA_SAFE_CHARS = b"|"  # see https://github.com/scrapy/w3lib/pull/25

    RFC3986_USERINFO_SAFE_CHARS = RFC3986_UNRESERVED + RFC3986_SUB_DELIMS + b":"
    _safe_chars = RFC3986_RESERVED + RFC3986_UNRESERVED + EXTRA_SAFE_CHARS + b"%"
    _path_safe_chars = _safe_chars.replace(b"#", b"")

    # Characters that are safe in all of:
    #
    # -   RFC 2396 + RFC 2732, as interpreted by Java 8’s java.net.URI class
    # -   RFC 3986
    # -   The URL living standard
    #
    # NOTE: % is currently excluded from these lists of characters, due to
    # limitations of the current safe_url_string implementation, but it should also
    # be escaped as %25 when it is not already being used as part of an escape
    # character.
    _USERINFO_SAFEST_CHARS = RFC3986_USERINFO_SAFE_CHARS.translate(None, delete=b":;=")
    _PATH_SAFEST_CHARS = _safe_chars.translate(None, delete=b"#[]|")
    _QUERY_SAFEST_CHARS = _PATH_SAFEST_CHARS
    _SPECIAL_QUERY_SAFEST_CHARS = _PATH_SAFEST_CHARS.translate(None, delete=b"'")
    _FRAGMENT_SAFEST_CHARS = _PATH_SAFEST_CHARS

    _ASCII_TAB_OR_NEWLINE_TRANSLATION_TABLE = {
        ord(char): None for char in _ASCII_TAB_OR_NEWLINE
    }

    def _strip(url: str) -> str:
        return url.strip(_C0_CONTROL_OR_SPACE).translate(
            _ASCII_TAB_OR_NEWLINE_TRANSLATION_TABLE
        )

    def safe_url_string(  # pylint: disable=too-many-locals
        url: StrOrBytes,
        encoding: str = "utf8",
        path_encoding: str = "utf8",
        quote_path: bool = True,
    ) -> str:
        """Return a URL equivalent to *url* that a wide range of web browsers and
        web servers consider valid.

        *url* is parsed according to the rules of the `URL living standard`_,
        and during serialization additional characters are percent-encoded to make
        the URL valid by additional URL standards.

        .. _URL living standard: https://url.spec.whatwg.org/

        The returned URL should be valid by *all* of the following URL standards
        known to be enforced by modern-day web browsers and web servers:

        -   `URL living standard`_

        -   `RFC 3986`_

        -   `RFC 2396`_ and `RFC 2732`_, as interpreted by `Java 8’s java.net.URI
            class`_.

        .. _Java 8’s java.net.URI class: https://docs.oracle.com/javase/8/docs/api/java/net/URI.html
        .. _RFC 2396: https://www.ietf.org/rfc/rfc2396.txt
        .. _RFC 2732: https://www.ietf.org/rfc/rfc2732.txt
        .. _RFC 3986: https://www.ietf.org/rfc/rfc3986.txt

        If a bytes URL is given, it is first converted to `str` using the given
        encoding (which defaults to 'utf-8'). If quote_path is True (default),
        path_encoding ('utf-8' by default) is used to encode URL path component
        which is then quoted. Otherwise, if quote_path is False, path component
        is not encoded or quoted. Given encoding is used for query string
        or form data.

        When passing an encoding, you should use the encoding of the
        original page (the page from which the URL was extracted from).

        Calling this function on an already "safe" URL will return the URL
        unmodified.
        """
        # urlsplit() chokes on bytes input with non-ASCII chars,
        # so let's decode (to Unicode) using page encoding:
        #   - it is assumed that a raw bytes input comes from a document
        #     encoded with the supplied encoding (or UTF8 by default)
        #   - if the supplied (or default) encoding chokes,
        #     percent-encode offending bytes
        decoded = to_unicode(url, encoding=encoding, errors="percentencode")
        parts = urlsplit(_strip(decoded))

        username, password, hostname, port = (
            parts.username,
            parts.password,
            parts.hostname,
            parts.port,
        )
        netloc_bytes = b""
        if username is not None or password is not None:
            if username is not None:
                safe_username = quote(unquote(username), _USERINFO_SAFEST_CHARS)
                netloc_bytes += safe_username.encode(encoding)
            if password is not None:
                netloc_bytes += b":"
                safe_password = quote(unquote(password), _USERINFO_SAFEST_CHARS)
                netloc_bytes += safe_password.encode(encoding)
            netloc_bytes += b"@"
        if hostname is not None:
            try:
                netloc_bytes += hostname.encode("idna")
            except UnicodeError:
                # IDNA encoding can fail for too long labels (>63 characters) or
                # missing labels (e.g. http://.example.com)
                netloc_bytes += hostname.encode(encoding)
        if port is not None:
            netloc_bytes += b":"
            netloc_bytes += str(port).encode(encoding)

        netloc = netloc_bytes.decode()

        # default encoding for path component SHOULD be UTF-8
        if quote_path:
            path = quote(parts.path.encode(path_encoding), _PATH_SAFEST_CHARS)
        else:
            path = parts.path

        if parts.scheme in _SPECIAL_SCHEMES:
            query = quote(parts.query.encode(encoding), _SPECIAL_QUERY_SAFEST_CHARS)
        else:
            query = quote(parts.query.encode(encoding), _QUERY_SAFEST_CHARS)

        return urlunsplit(
            (
                parts.scheme,
                netloc,
                path,
                query,
                quote(parts.fragment.encode(encoding), _FRAGMENT_SAFEST_CHARS),
            )
        )

    _parent_dirs = re.compile(r"/?(\.\./)+")

    def safe_download_url(
        url: StrOrBytes, encoding: str = "utf8", path_encoding: str = "utf8"
    ) -> str:
        """Make a url for download. This will call safe_url_string
        and then strip the fragment, if one exists. The path will
        be normalised.

        If the path is outside the document root, it will be changed
        to be within the document root.
        """
        safe_url = safe_url_string(url, encoding, path_encoding)
        scheme, netloc, path, query, _ = urlsplit(safe_url)
        if path:
            path = _parent_dirs.sub("", posixpath.normpath(path))
            if safe_url.endswith("/") and not path.endswith("/"):
                path += "/"
        else:
            path = "/"
        return urlunsplit((scheme, netloc, path, query, ""))

    def is_url(text: str) -> bool:
        return text.partition("://")[0] in ("file", "http", "https")

    @overload
    def url_query_parameter(
        url: StrOrBytes,
        parameter: str,
        default: None = None,
        keep_blank_values: bool | int = 0,
    ) -> str | None: ...

    @overload
    def url_query_parameter(
        url: StrOrBytes,
        parameter: str,
        default: str,
        keep_blank_values: bool | int = 0,
    ) -> str: ...

    def url_query_parameter(
        url: StrOrBytes,
        parameter: str,
        default: str | None = None,
        keep_blank_values: bool | int = 0,
    ) -> str | None:
        """Return the value of a url parameter, given the url and parameter name

        General case:

        >>> import w3lib.url
        >>> w3lib.url.url_query_parameter("product.html?id=200&foo=bar", "id")
        '200'
        >>>

        Return a default value if the parameter is not found:

        >>> w3lib.url.url_query_parameter("product.html?id=200&foo=bar", "notthere", "mydefault")
        'mydefault'
        >>>

        Returns None if `keep_blank_values` not set or 0 (default):

        >>> w3lib.url.url_query_parameter("product.html?id=", "id")
        >>>

        Returns an empty string if `keep_blank_values` set to 1:

        >>> w3lib.url.url_query_parameter("product.html?id=", "id", keep_blank_values=1)
        ''
        >>>

        """

        queryparams = parse_qs(
            urlsplit(str(url))[3], keep_blank_values=bool(keep_blank_values)
        )
        if parameter in queryparams:
            return queryparams[parameter][0]
        return default

    def url_query_cleaner(
        url: StrOrBytes,
        parameterlist: StrOrBytes | Sequence[StrOrBytes] = (),
        sep: str = "&",
        kvsep: str = "=",
        remove: bool = False,
        unique: bool = True,
        keep_fragments: bool = False,
    ) -> str:
        """Clean URL arguments leaving only those passed in the parameterlist keeping order

        >>> import w3lib.url
        >>> w3lib.url.url_query_cleaner("product.html?id=200&foo=bar&name=wired", ('id',))
        'product.html?id=200'
        >>> w3lib.url.url_query_cleaner("product.html?id=200&foo=bar&name=wired", ['id', 'name'])
        'product.html?id=200&name=wired'
        >>>

        If `unique` is ``False``, do not remove duplicated keys

        >>> w3lib.url.url_query_cleaner("product.html?d=1&e=b&d=2&d=3&other=other", ['d'], unique=False)
        'product.html?d=1&d=2&d=3'
        >>>

        If `remove` is ``True``, leave only those **not in parameterlist**.

        >>> w3lib.url.url_query_cleaner("product.html?id=200&foo=bar&name=wired", ['id'], remove=True)
        'product.html?foo=bar&name=wired'
        >>> w3lib.url.url_query_cleaner("product.html?id=2&foo=bar&name=wired", ['id', 'foo'], remove=True)
        'product.html?name=wired'
        >>>

        By default, URL fragments are removed. If you need to preserve fragments,
        pass the ``keep_fragments`` argument as ``True``.

        >>> w3lib.url.url_query_cleaner('http://domain.tld/?bla=123#123123', ['bla'], remove=True, keep_fragments=True)
        'http://domain.tld/#123123'

        """

        if isinstance(parameterlist, (str, bytes)):
            parameterlist = [parameterlist]
        url, fragment = urldefrag(url)
        url = cast(str, url)
        fragment = cast(str, fragment)
        base, _, query = url.partition("?")
        seen = set()
        querylist = []
        for ksv in query.split(sep):
            if not ksv:
                continue
            k, _, _ = ksv.partition(kvsep)
            if unique and k in seen:
                continue
            if remove and k in parameterlist:
                continue
            if not remove and k not in parameterlist:
                continue
            querylist.append(ksv)
            seen.add(k)
        url = "?".join([base, sep.join(querylist)]) if querylist else base
        if keep_fragments and fragment:
            url += "#" + fragment
        return url

    def _add_or_replace_parameters(url: str, params: dict[str, str]) -> str:
        parsed = urlsplit(url)
        current_args = parse_qsl(parsed.query, keep_blank_values=True)

        new_args = []
        seen_params = set()
        for name, value in current_args:
            if name not in params:
                new_args.append((name, value))
            elif name not in seen_params:
                new_args.append((name, params[name]))
                seen_params.add(name)

        not_modified_args = [
            (name, value) for name, value in params.items() if name not in seen_params
        ]
        new_args += not_modified_args

        query = urlencode(new_args)
        return urlunsplit(parsed._replace(query=query))

    def add_or_replace_parameter(url: str, name: str, new_value: str) -> str:
        """Add or remove a parameter to a given url

        >>> import w3lib.url
        >>> w3lib.url.add_or_replace_parameter('http://www.example.com/index.php', 'arg', 'v')
        'http://www.example.com/index.php?arg=v'
        >>> w3lib.url.add_or_replace_parameter('http://www.example.com/index.php?arg1=v1&arg2=v2&arg3=v3', 'arg4', 'v4')
        'http://www.example.com/index.php?arg1=v1&arg2=v2&arg3=v3&arg4=v4'
        >>> w3lib.url.add_or_replace_parameter('http://www.example.com/index.php?arg1=v1&arg2=v2&arg3=v3', 'arg3', 'v3new')
        'http://www.example.com/index.php?arg1=v1&arg2=v2&arg3=v3new'
        >>>

        """
        return _add_or_replace_parameters(url, {name: new_value})

    def add_or_replace_parameters(url: str, new_parameters: dict[str, str]) -> str:
        """Add or remove a parameters to a given url

        >>> import w3lib.url
        >>> w3lib.url.add_or_replace_parameters('http://www.example.com/index.php', {'arg': 'v'})
        'http://www.example.com/index.php?arg=v'
        >>> args = {'arg4': 'v4', 'arg3': 'v3new'}
        >>> w3lib.url.add_or_replace_parameters('http://www.example.com/index.php?arg1=v1&arg2=v2&arg3=v3', args)
        'http://www.example.com/index.php?arg1=v1&arg2=v2&arg3=v3new&arg4=v4'
        >>>

        """
        return _add_or_replace_parameters(url, new_parameters)

    def path_to_file_uri(path: str) -> str:
        """Convert local filesystem path to legal File URIs as described in:
        http://en.wikipedia.org/wiki/File_URI_scheme
        """
        x = pathname2url(os.path.abspath(path))
        return f"file:///{x.lstrip('/')}"

    def file_uri_to_path(uri: str) -> str:
        """Convert File URI to local filesystem path according to:
        http://en.wikipedia.org/wiki/File_URI_scheme
        """
        uri_path = urlparse(uri).path
        return url2pathname(uri_path)

    def any_to_uri(uri_or_path: str) -> str:
        """If given a path name, return its File URI, otherwise return it
        unmodified
        """
        if os.path.splitdrive(uri_or_path)[0]:
            return path_to_file_uri(uri_or_path)
        u = urlparse(uri_or_path)
        return uri_or_path if u.scheme else path_to_file_uri(uri_or_path)

    # ASCII characters.
    _char = set(map(chr, range(127)))

    # RFC 2045 token.
    _token = r"[{}]+".format(
        re.escape(
            "".join(
                _char
                -
                # Control characters.
                set(map(chr, range(0, 32)))
                -
                # tspecials and space.
                set('()<>@,;:\\"/[]?= ')
            )
        )
    )

    # RFC 822 quoted-string, without surrounding quotation marks.
    _quoted_string = r"(?:[{}]|(?:\\[{}]))*".format(
        re.escape("".join(_char - {'"', "\\", "\r"})), re.escape("".join(_char))
    )

    # Encode the regular expression strings to make them into bytes, as Python 3
    # bytes have no format() method, but bytes must be passed to re.compile() in
    # order to make a pattern object that can be used to match on bytes.

    # RFC 2397 mediatype.
    _mediatype_pattern = re.compile(r"{token}/{token}".format(token=_token).encode())
    _mediatype_parameter_pattern = re.compile(
        r';({token})=(?:({token})|"({quoted})")'.format(
            token=_token, quoted=_quoted_string
        ).encode()
    )

    class ParseDataURIResult(NamedTuple):
        """Named tuple returned by :func:`parse_data_uri`."""

        #: MIME type type and subtype, separated by / (e.g. ``"text/plain"``).
        media_type: str
        #: MIME type parameters (e.g. ``{"charset": "US-ASCII"}``).
        media_type_parameters: dict[str, str]
        #: Data, decoded if it was encoded in base64 format.
        data: bytes

    def parse_data_uri(uri: StrOrBytes) -> ParseDataURIResult:
        """Parse a data: URI into :class:`ParseDataURIResult`."""
        if not isinstance(uri, bytes):
            uri = safe_url_string(uri).encode("ascii")

        try:
            scheme, uri = uri.split(b":", 1)
        except ValueError:
            raise ValueError("invalid URI")
        if scheme.lower() != b"data":
            raise ValueError("not a data URI")

        # RFC 3986 section 2.1 allows percent encoding to escape characters that
        # would be interpreted as delimiters, implying that actual delimiters
        # should not be percent-encoded.
        # Decoding before parsing will allow malformed URIs with percent-encoded
        # delimiters, but it makes parsing easier and should not affect
        # well-formed URIs, as the delimiters used in this URI scheme are not
        # allowed, percent-encoded or not, in tokens.
        uri = unquote_to_bytes(uri)

        media_type = "text/plain"
        media_type_params = {}

        m = _mediatype_pattern.match(uri)
        if m:
            media_type = m.group().decode()
            uri = uri[m.end() :]
        else:
            media_type_params["charset"] = "US-ASCII"

        while True:
            m = _mediatype_parameter_pattern.match(uri)
            if m:
                attribute, value, value_quoted = m.groups()
                if value_quoted:
                    value = re.sub(rb"\\(.)", rb"\1", value_quoted)
                media_type_params[attribute.decode()] = value.decode()
                uri = uri[m.end() :]
            else:
                break

        try:
            is_base64, data = uri.split(b",", 1)
        except ValueError:
            raise ValueError("invalid data URI")
        if is_base64:
            if is_base64 != b";base64":
                raise ValueError("invalid data URI")
            data = base64.b64decode(data)

        return ParseDataURIResult(media_type, media_type_params, data)

    __all__ = [
        "add_or_replace_parameter",
        "add_or_replace_parameters",
        "any_to_uri",
        "canonicalize_url",
        "file_uri_to_path",
        "is_url",
        "parse_data_uri",
        "path_to_file_uri",
        "safe_download_url",
        "safe_url_string",
        "url_query_cleaner",
        "url_query_parameter",
    ]

    def _safe_ParseResult(
        parts: ParseResult, encoding: str = "utf8", path_encoding: str = "utf8"
    ) -> tuple[str, str, str, str, str, str]:
        # IDNA encoding can fail for too long labels (>63 characters)
        # or missing labels (e.g. http://.example.com)
        try:
            netloc = parts.netloc.encode("idna").decode()
        except UnicodeError:
            netloc = parts.netloc

        return (
            parts.scheme,
            netloc,
            quote(parts.path.encode(path_encoding), _path_safe_chars),
            quote(parts.params.encode(path_encoding), _safe_chars),
            quote(parts.query.encode(encoding), _safe_chars),
            quote(parts.fragment.encode(encoding), _safe_chars),
        )

    def canonicalize_url(
        url: StrOrBytes | ParseResult,
        keep_blank_values: bool = True,
        keep_fragments: bool = False,
        encoding: str | None = None,
    ) -> str:
        r"""Canonicalize the given url by applying the following procedures:

        - make the URL safe
        - sort query arguments, first by key, then by value
        - normalize all spaces (in query arguments) '+' (plus symbol)
        - normalize percent encodings case (%2f -> %2F)
        - remove query arguments with blank values (unless `keep_blank_values` is True)
        - remove fragments (unless `keep_fragments` is True)

        The url passed can be bytes or unicode, while the url returned is
        always a native str (bytes in Python 2, unicode in Python 3).

        >>> import w3lib.url
        >>>
        >>> # sorting query arguments
        >>> w3lib.url.canonicalize_url('http://www.example.com/do?c=3&b=5&b=2&a=50')
        'http://www.example.com/do?a=50&b=2&b=5&c=3'
        >>>
        >>> # UTF-8 conversion + percent-encoding of non-ASCII characters
        >>> w3lib.url.canonicalize_url('http://www.example.com/r\u00e9sum\u00e9')
        'http://www.example.com/r%C3%A9sum%C3%A9'
        >>>

        For more examples, see the tests in `tests/test_url.py`.
        """
        # If supplied `encoding` is not compatible with all characters in `url`,
        # fallback to UTF-8 as safety net.
        # UTF-8 can handle all Unicode characters,
        # so we should be covered regarding URL normalization,
        # if not for proper URL expected by remote website.
        if isinstance(url, str):
            url = _strip(url)
        try:
            scheme, netloc, path, params, query, fragment = _safe_ParseResult(
                parse_url(url), encoding=encoding or "utf8"
            )
        except UnicodeEncodeError:
            scheme, netloc, path, params, query, fragment = _safe_ParseResult(
                parse_url(url), encoding="utf8"
            )

        # 1. decode query-string as UTF-8 (or keep raw bytes),
        #    sort values,
        #    and percent-encode them back

        # Python's urllib.parse.parse_qsl does not work as wanted
        # for percent-encoded characters that do not match passed encoding,
        # they get lost.
        #
        # e.g., 'q=b%a3' becomes [('q', 'b\ufffd')]
        # (ie. with 'REPLACEMENT CHARACTER' (U+FFFD),
        #      instead of \xa3 that you get with Python2's parse_qsl)
        #
        # what we want here is to keep raw bytes, and percent encode them
        # so as to preserve whatever encoding what originally used.
        #
        # See https://tools.ietf.org/html/rfc3987#section-6.4:
        #
        # For example, it is possible to have a URI reference of
        # "http://www.example.org/r%E9sum%E9.xml#r%C3%A9sum%C3%A9", where the
        # document name is encoded in iso-8859-1 based on server settings, but
        # where the fragment identifier is encoded in UTF-8 according to
        # [XPointer]. The IRI corresponding to the above URI would be (in XML
        # notation)
        # "http://www.example.org/r%E9sum%E9.xml#r&#xE9;sum&#xE9;".
        # Similar considerations apply to query parts.  The functionality of
        # IRIs (namely, to be able to include non-ASCII characters) can only be
        # used if the query part is encoded in UTF-8.
        keyvals = parse_qsl_to_bytes(query, keep_blank_values)

        keyvals.sort()
        query = urlencode(keyvals)

        # 2. decode percent-encoded sequences in path as UTF-8 (or keep raw bytes)
        #    and percent-encode path again (this normalizes to upper-case %XX)
        uqp = _unquotepath(path)
        path = quote(uqp, _path_safe_chars) or "/"

        fragment = "" if not keep_fragments else fragment

        # Apply lowercase to the domain, but not to the userinfo.
        netloc_parts = netloc.split("@")
        netloc_parts[-1] = netloc_parts[-1].lower().rstrip(":")
        netloc = "@".join(netloc_parts)

        # every part should be safe already
        return urlunparse((scheme, netloc, path, params, query, fragment))

    def _unquotepath(path: str) -> bytes:
        for reserved in ("2f", "2F", "3f", "3F"):
            path = path.replace("%" + reserved, "%25" + reserved.upper())

        # standard lib's unquote() does not work for non-UTF-8
        # percent-escaped characters, they get lost.
        # e.g., '%a3' becomes 'REPLACEMENT CHARACTER' (U+FFFD)
        #
        # unquote_to_bytes() returns raw bytes instead
        return unquote_to_bytes(path)

    def parse_url(
        url: StrOrBytes | ParseResult, encoding: str | None = None
    ) -> ParseResult:
        """Return urlparsed url from the given argument (which could be an already
        parsed url)
        """
        if isinstance(url, ParseResult):
            return url
        return urlparse(to_unicode(url, encoding))

    def parse_qsl_to_bytes(
        qs: str, keep_blank_values: bool = False
    ) -> list[tuple[bytes, bytes]]:
        """Parse a query given as a string argument.

        Data are returned as a list of name, value pairs as bytes.

        Arguments:

        qs: percent-encoded query string to be parsed

        keep_blank_values: flag indicating whether blank values in
            percent-encoded queries should be treated as blank strings.  A
            true value indicates that blanks should be retained as blank
            strings.  The default false value indicates that blank values
            are to be ignored and treated as if they were  not included.

        """
        # This code is the same as Python3's parse_qsl()
        # (at https://hg.python.org/cpython/rev/c38ac7ab8d9a)
        # except for the unquote(s, encoding, errors) calls replaced
        # with unquote_to_bytes(s)
        coerce_args = cast(Callable[..., tuple[str, Callable[..., bytes]]], _coerce_args)
        qs, _coerce_result = coerce_args(qs)
        pairs = [s2 for s1 in qs.split("&") for s2 in s1.split(";")]
        r = []
        for name_value in pairs:
            if not name_value:
                continue
            nv = name_value.split("=", 1)
            if len(nv) != 2:
                # Handle case of a control-name with no equal sign
                if keep_blank_values:
                    nv.append("")
                else:
                    continue
            if len(nv[1]) or keep_blank_values:
                name: StrOrBytes = nv[0].replace("+", " ")
                name = unquote_to_bytes(name)
                name = _coerce_result(name)
                value: StrOrBytes = nv[1].replace("+", " ")
                value = unquote_to_bytes(value)
                value = _coerce_result(value)
                r.append((name, value))
        return r