--- a/lib/python3.8/site-packages/pip/_internal/req/req_file.py	Mon Jul 27 03:47:31 2020 -0400
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,546 +0,0 @@
-"""
-Requirements file parsing
-"""
-
-# The following comment should be removed at some point in the future.
-# mypy: strict-optional=False
-
-from __future__ import absolute_import
-
-import optparse
-import os
-import re
-import shlex
-import sys
-
-from pip._vendor.six.moves import filterfalse
-from pip._vendor.six.moves.urllib import parse as urllib_parse
-
-from pip._internal.cli import cmdoptions
-from pip._internal.exceptions import (
-    InstallationError,
-    RequirementsFileParseError,
-)
-from pip._internal.models.search_scope import SearchScope
-from pip._internal.req.constructors import (
-    install_req_from_editable,
-    install_req_from_line,
-)
-from pip._internal.utils.encoding import auto_decode
-from pip._internal.utils.typing import MYPY_CHECK_RUNNING
-from pip._internal.utils.urls import get_url_scheme
-
-if MYPY_CHECK_RUNNING:
-    from optparse import Values
-    from typing import (
-        Any, Callable, Iterator, List, NoReturn, Optional, Text, Tuple,
-    )
-
-    from pip._internal.req import InstallRequirement
-    from pip._internal.cache import WheelCache
-    from pip._internal.index.package_finder import PackageFinder
-    from pip._internal.network.session import PipSession
-
-    ReqFileLines = Iterator[Tuple[int, Text]]
-
-    LineParser = Callable[[Text], Tuple[str, Values]]
-
-
-__all__ = ['parse_requirements']
-
-SCHEME_RE = re.compile(r'^(http|https|file):', re.I)
-COMMENT_RE = re.compile(r'(^|\s+)#.*$')
-
-# Matches environment variable-style values in '${MY_VARIABLE_1}' with the
-# variable name consisting of only uppercase letters, digits or the '_'
-# (underscore). This follows the POSIX standard defined in IEEE Std 1003.1,
-# 2013 Edition.
-ENV_VAR_RE = re.compile(r'(?P<var>\$\{(?P<name>[A-Z0-9_]+)\})')
-
-SUPPORTED_OPTIONS = [
-    cmdoptions.index_url,
-    cmdoptions.extra_index_url,
-    cmdoptions.no_index,
-    cmdoptions.constraints,
-    cmdoptions.requirements,
-    cmdoptions.editable,
-    cmdoptions.find_links,
-    cmdoptions.no_binary,
-    cmdoptions.only_binary,
-    cmdoptions.require_hashes,
-    cmdoptions.pre,
-    cmdoptions.trusted_host,
-    cmdoptions.always_unzip,  # Deprecated
-]  # type: List[Callable[..., optparse.Option]]
-
-# options to be passed to requirements
-SUPPORTED_OPTIONS_REQ = [
-    cmdoptions.install_options,
-    cmdoptions.global_options,
-    cmdoptions.hash,
-]  # type: List[Callable[..., optparse.Option]]
-
-# the 'dest' string values
-SUPPORTED_OPTIONS_REQ_DEST = [str(o().dest) for o in SUPPORTED_OPTIONS_REQ]
-
-
-class ParsedLine(object):
-    def __init__(
-        self,
-        filename,  # type: str
-        lineno,  # type: int
-        comes_from,  # type: str
-        args,  # type: str
-        opts,  # type: Values
-        constraint,  # type: bool
-    ):
-        # type: (...) -> None
-        self.filename = filename
-        self.lineno = lineno
-        self.comes_from = comes_from
-        self.args = args
-        self.opts = opts
-        self.constraint = constraint
-
-
-def parse_requirements(
-    filename,  # type: str
-    session,  # type: PipSession
-    finder=None,  # type: Optional[PackageFinder]
-    comes_from=None,  # type: Optional[str]
-    options=None,  # type: Optional[optparse.Values]
-    constraint=False,  # type: bool
-    wheel_cache=None,  # type: Optional[WheelCache]
-    use_pep517=None  # type: Optional[bool]
-):
-    # type: (...) -> Iterator[InstallRequirement]
-    """Parse a requirements file and yield InstallRequirement instances.
-
-    :param filename:    Path or url of requirements file.
-    :param session:     PipSession instance.
-    :param finder:      Instance of pip.index.PackageFinder.
-    :param comes_from:  Origin description of requirements.
-    :param options:     cli options.
-    :param constraint:  If true, parsing a constraint file rather than
-        requirements file.
-    :param wheel_cache: Instance of pip.wheel.WheelCache
-    :param use_pep517:  Value of the --use-pep517 option.
-    """
-    skip_requirements_regex = (
-        options.skip_requirements_regex if options else None
-    )
-    line_parser = get_line_parser(finder)
-    parser = RequirementsFileParser(
-        session, line_parser, comes_from, skip_requirements_regex
-    )
-
-    for parsed_line in parser.parse(filename, constraint):
-        req = handle_line(
-            parsed_line, finder, options, session, wheel_cache, use_pep517
-        )
-        if req is not None:
-            yield req
-
-
-def preprocess(content, skip_requirements_regex):
-    # type: (Text, Optional[str]) -> ReqFileLines
-    """Split, filter, and join lines, and return a line iterator
-
-    :param content: the content of the requirements file
-    :param options: cli options
-    """
-    lines_enum = enumerate(content.splitlines(), start=1)  # type: ReqFileLines
-    lines_enum = join_lines(lines_enum)
-    lines_enum = ignore_comments(lines_enum)
-    if skip_requirements_regex:
-        lines_enum = skip_regex(lines_enum, skip_requirements_regex)
-    lines_enum = expand_env_variables(lines_enum)
-    return lines_enum
-
-
-def handle_line(
-    line,  # type: ParsedLine
-    finder=None,  # type: Optional[PackageFinder]
-    options=None,  # type: Optional[optparse.Values]
-    session=None,  # type: Optional[PipSession]
-    wheel_cache=None,  # type: Optional[WheelCache]
-    use_pep517=None,  # type: Optional[bool]
-):
-    # type: (...) -> Optional[InstallRequirement]
-    """Handle a single parsed requirements line; This can result in
-    creating/yielding requirements, or updating the finder.
-
-    For lines that contain requirements, the only options that have an effect
-    are from SUPPORTED_OPTIONS_REQ, and they are scoped to the
-    requirement. Other options from SUPPORTED_OPTIONS may be present, but are
-    ignored.
-
-    For lines that do not contain requirements, the only options that have an
-    effect are from SUPPORTED_OPTIONS. Options from SUPPORTED_OPTIONS_REQ may
-    be present, but are ignored. These lines may contain multiple options
-    (although our docs imply only one is supported), and all our parsed and
-    affect the finder.
-    """
-
-    # preserve for the nested code path
-    line_comes_from = '%s %s (line %s)' % (
-        '-c' if line.constraint else '-r', line.filename, line.lineno,
-    )
-
-    # return a line requirement
-    if line.args:
-        isolated = options.isolated_mode if options else False
-        if options:
-            cmdoptions.check_install_build_global(options, line.opts)
-        # get the options that apply to requirements
-        req_options = {}
-        for dest in SUPPORTED_OPTIONS_REQ_DEST:
-            if dest in line.opts.__dict__ and line.opts.__dict__[dest]:
-                req_options[dest] = line.opts.__dict__[dest]
-        line_source = 'line {} of {}'.format(line.lineno, line.filename)
-        return install_req_from_line(
-            line.args,
-            comes_from=line_comes_from,
-            use_pep517=use_pep517,
-            isolated=isolated,
-            options=req_options,
-            wheel_cache=wheel_cache,
-            constraint=line.constraint,
-            line_source=line_source,
-        )
-
-    # return an editable requirement
-    elif line.opts.editables:
-        isolated = options.isolated_mode if options else False
-        return install_req_from_editable(
-            line.opts.editables[0], comes_from=line_comes_from,
-            use_pep517=use_pep517,
-            constraint=line.constraint, isolated=isolated,
-            wheel_cache=wheel_cache
-        )
-
-    # percolate hash-checking option upward
-    elif line.opts.require_hashes:
-        options.require_hashes = line.opts.require_hashes
-
-    # set finder options
-    elif finder:
-        find_links = finder.find_links
-        index_urls = finder.index_urls
-        if line.opts.index_url:
-            index_urls = [line.opts.index_url]
-        if line.opts.no_index is True:
-            index_urls = []
-        if line.opts.extra_index_urls:
-            index_urls.extend(line.opts.extra_index_urls)
-        if line.opts.find_links:
-            # FIXME: it would be nice to keep track of the source
-            # of the find_links: support a find-links local path
-            # relative to a requirements file.
-            value = line.opts.find_links[0]
-            req_dir = os.path.dirname(os.path.abspath(line.filename))
-            relative_to_reqs_file = os.path.join(req_dir, value)
-            if os.path.exists(relative_to_reqs_file):
-                value = relative_to_reqs_file
-            find_links.append(value)
-
-        search_scope = SearchScope(
-            find_links=find_links,
-            index_urls=index_urls,
-        )
-        finder.search_scope = search_scope
-
-        if line.opts.pre:
-            finder.set_allow_all_prereleases()
-
-        if session:
-            for host in line.opts.trusted_hosts or []:
-                source = 'line {} of {}'.format(line.lineno, line.filename)
-                session.add_trusted_host(host, source=source)
-
-    return None
-
-
-class RequirementsFileParser(object):
-    def __init__(
-        self,
-        session,  # type: PipSession
-        line_parser,  # type: LineParser
-        comes_from,  # type: str
-        skip_requirements_regex,  # type: Optional[str]
-    ):
-        # type: (...) -> None
-        self._session = session
-        self._line_parser = line_parser
-        self._comes_from = comes_from
-        self._skip_requirements_regex = skip_requirements_regex
-
-    def parse(self, filename, constraint):
-        # type: (str, bool) -> Iterator[ParsedLine]
-        """Parse a given file, yielding parsed lines.
-        """
-        for line in self._parse_and_recurse(filename, constraint):
-            yield line
-
-    def _parse_and_recurse(self, filename, constraint):
-        # type: (str, bool) -> Iterator[ParsedLine]
-        for line in self._parse_file(filename, constraint):
-            if (
-                not line.args and
-                not line.opts.editables and
-                (line.opts.requirements or line.opts.constraints)
-            ):
-                # parse a nested requirements file
-                if line.opts.requirements:
-                    req_path = line.opts.requirements[0]
-                    nested_constraint = False
-                else:
-                    req_path = line.opts.constraints[0]
-                    nested_constraint = True
-
-                # original file is over http
-                if SCHEME_RE.search(filename):
-                    # do a url join so relative paths work
-                    req_path = urllib_parse.urljoin(filename, req_path)
-                # original file and nested file are paths
-                elif not SCHEME_RE.search(req_path):
-                    # do a join so relative paths work
-                    req_path = os.path.join(
-                        os.path.dirname(filename), req_path,
-                    )
-
-                for inner_line in self._parse_and_recurse(
-                    req_path, nested_constraint,
-                ):
-                    yield inner_line
-            else:
-                yield line
-
-    def _parse_file(self, filename, constraint):
-        # type: (str, bool) -> Iterator[ParsedLine]
-        _, content = get_file_content(
-            filename, self._session, comes_from=self._comes_from
-        )
-
-        lines_enum = preprocess(content, self._skip_requirements_regex)
-
-        for line_number, line in lines_enum:
-            try:
-                args_str, opts = self._line_parser(line)
-            except OptionParsingError as e:
-                # add offending line
-                msg = 'Invalid requirement: %s\n%s' % (line, e.msg)
-                raise RequirementsFileParseError(msg)
-
-            yield ParsedLine(
-                filename,
-                line_number,
-                self._comes_from,
-                args_str,
-                opts,
-                constraint,
-            )
-
-
-def get_line_parser(finder):
-    # type: (Optional[PackageFinder]) -> LineParser
-    def parse_line(line):
-        # type: (Text) -> Tuple[str, Values]
-        # Build new parser for each line since it accumulates appendable
-        # options.
-        parser = build_parser()
-        defaults = parser.get_default_values()
-        defaults.index_url = None
-        if finder:
-            defaults.format_control = finder.format_control
-
-        args_str, options_str = break_args_options(line)
-        # Prior to 2.7.3, shlex cannot deal with unicode entries
-        if sys.version_info < (2, 7, 3):
-            # https://github.com/python/mypy/issues/1174
-            options_str = options_str.encode('utf8')  # type: ignore
-
-        # https://github.com/python/mypy/issues/1174
-        opts, _ = parser.parse_args(
-            shlex.split(options_str), defaults)  # type: ignore
-
-        return args_str, opts
-
-    return parse_line
-
-
-def break_args_options(line):
-    # type: (Text) -> Tuple[str, Text]
-    """Break up the line into an args and options string.  We only want to shlex
-    (and then optparse) the options, not the args.  args can contain markers
-    which are corrupted by shlex.
-    """
-    tokens = line.split(' ')
-    args = []
-    options = tokens[:]
-    for token in tokens:
-        if token.startswith('-') or token.startswith('--'):
-            break
-        else:
-            args.append(token)
-            options.pop(0)
-    return ' '.join(args), ' '.join(options)  # type: ignore
-
-
-class OptionParsingError(Exception):
-    def __init__(self, msg):
-        # type: (str) -> None
-        self.msg = msg
-
-
-def build_parser():
-    # type: () -> optparse.OptionParser
-    """
-    Return a parser for parsing requirement lines
-    """
-    parser = optparse.OptionParser(add_help_option=False)
-
-    option_factories = SUPPORTED_OPTIONS + SUPPORTED_OPTIONS_REQ
-    for option_factory in option_factories:
-        option = option_factory()
-        parser.add_option(option)
-
-    # By default optparse sys.exits on parsing errors. We want to wrap
-    # that in our own exception.
-    def parser_exit(self, msg):
-        # type: (Any, str) -> NoReturn
-        raise OptionParsingError(msg)
-    # NOTE: mypy disallows assigning to a method
-    #       https://github.com/python/mypy/issues/2427
-    parser.exit = parser_exit  # type: ignore
-
-    return parser
-
-
-def join_lines(lines_enum):
-    # type: (ReqFileLines) -> ReqFileLines
-    """Joins a line ending in '\' with the previous line (except when following
-    comments).  The joined line takes on the index of the first line.
-    """
-    primary_line_number = None
-    new_line = []  # type: List[Text]
-    for line_number, line in lines_enum:
-        if not line.endswith('\\') or COMMENT_RE.match(line):
-            if COMMENT_RE.match(line):
-                # this ensures comments are always matched later
-                line = ' ' + line
-            if new_line:
-                new_line.append(line)
-                yield primary_line_number, ''.join(new_line)
-                new_line = []
-            else:
-                yield line_number, line
-        else:
-            if not new_line:
-                primary_line_number = line_number
-            new_line.append(line.strip('\\'))
-
-    # last line contains \
-    if new_line:
-        yield primary_line_number, ''.join(new_line)
-
-    # TODO: handle space after '\'.
-
-
-def ignore_comments(lines_enum):
-    # type: (ReqFileLines) -> ReqFileLines
-    """
-    Strips comments and filter empty lines.
-    """
-    for line_number, line in lines_enum:
-        line = COMMENT_RE.sub('', line)
-        line = line.strip()
-        if line:
-            yield line_number, line
-
-
-def skip_regex(lines_enum, pattern):
-    # type: (ReqFileLines, str) -> ReqFileLines
-    """
-    Skip lines that match the provided pattern
-
-    Note: the regex pattern is only built once
-    """
-    matcher = re.compile(pattern)
-    lines_enum = filterfalse(lambda e: matcher.search(e[1]), lines_enum)
-    return lines_enum
-
-
-def expand_env_variables(lines_enum):
-    # type: (ReqFileLines) -> ReqFileLines
-    """Replace all environment variables that can be retrieved via `os.getenv`.
-
-    The only allowed format for environment variables defined in the
-    requirement file is `${MY_VARIABLE_1}` to ensure two things:
-
-    1. Strings that contain a `$` aren't accidentally (partially) expanded.
-    2. Ensure consistency across platforms for requirement files.
-
-    These points are the result of a discussion on the `github pull
-    request #3514 <https://github.com/pypa/pip/pull/3514>`_.
-
-    Valid characters in variable names follow the `POSIX standard
-    <http://pubs.opengroup.org/onlinepubs/9699919799/>`_ and are limited
-    to uppercase letter, digits and the `_` (underscore).
-    """
-    for line_number, line in lines_enum:
-        for env_var, var_name in ENV_VAR_RE.findall(line):
-            value = os.getenv(var_name)
-            if not value:
-                continue
-
-            line = line.replace(env_var, value)
-
-        yield line_number, line
-
-
-def get_file_content(url, session, comes_from=None):
-    # type: (str, PipSession, Optional[str]) -> Tuple[str, Text]
-    """Gets the content of a file; it may be a filename, file: URL, or
-    http: URL.  Returns (location, content).  Content is unicode.
-    Respects # -*- coding: declarations on the retrieved files.
-
-    :param url:         File path or url.
-    :param session:     PipSession instance.
-    :param comes_from:  Origin description of requirements.
-    """
-    scheme = get_url_scheme(url)
-
-    if scheme in ['http', 'https']:
-        # FIXME: catch some errors
-        resp = session.get(url)
-        resp.raise_for_status()
-        return resp.url, resp.text
-
-    elif scheme == 'file':
-        if comes_from and comes_from.startswith('http'):
-            raise InstallationError(
-                'Requirements file %s references URL %s, which is local'
-                % (comes_from, url))
-
-        path = url.split(':', 1)[1]
-        path = path.replace('\\', '/')
-        match = _url_slash_drive_re.match(path)
-        if match:
-            path = match.group(1) + ':' + path.split('|', 1)[1]
-        path = urllib_parse.unquote(path)
-        if path.startswith('/'):
-            path = '/' + path.lstrip('/')
-        url = path
-
-    try:
-        with open(url, 'rb') as f:
-            content = auto_decode(f.read())
-    except IOError as exc:
-        raise InstallationError(
-            'Could not open requirements file: %s' % str(exc)
-        )
-    return url, content
-
-
-_url_slash_drive_re = re.compile(r'/*([a-z])\|', re.I)