--- a/lib/python3.8/site-packages/pip/_internal/req/constructors.py	Mon Jul 27 03:47:31 2020 -0400
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,436 +0,0 @@
-"""Backing implementation for InstallRequirement's various constructors
-
-The idea here is that these formed a major chunk of InstallRequirement's size
-so, moving them and support code dedicated to them outside of that class
-helps creates for better understandability for the rest of the code.
-
-These are meant to be used elsewhere within pip to create instances of
-InstallRequirement.
-"""
-
-# The following comment should be removed at some point in the future.
-# mypy: strict-optional=False
-
-import logging
-import os
-import re
-
-from pip._vendor.packaging.markers import Marker
-from pip._vendor.packaging.requirements import InvalidRequirement, Requirement
-from pip._vendor.packaging.specifiers import Specifier
-from pip._vendor.pkg_resources import RequirementParseError, parse_requirements
-
-from pip._internal.exceptions import InstallationError
-from pip._internal.models.index import PyPI, TestPyPI
-from pip._internal.models.link import Link
-from pip._internal.models.wheel import Wheel
-from pip._internal.pyproject import make_pyproject_path
-from pip._internal.req.req_install import InstallRequirement
-from pip._internal.utils.filetypes import ARCHIVE_EXTENSIONS
-from pip._internal.utils.misc import is_installable_dir, splitext
-from pip._internal.utils.typing import MYPY_CHECK_RUNNING
-from pip._internal.utils.urls import path_to_url
-from pip._internal.vcs import is_url, vcs
-
-if MYPY_CHECK_RUNNING:
-    from typing import (
-        Any, Dict, Optional, Set, Tuple, Union,
-    )
-    from pip._internal.cache import WheelCache
-
-
-__all__ = [
-    "install_req_from_editable", "install_req_from_line",
-    "parse_editable"
-]
-
-logger = logging.getLogger(__name__)
-operators = Specifier._operators.keys()
-
-
-def is_archive_file(name):
-    # type: (str) -> bool
-    """Return True if `name` is a considered as an archive file."""
-    ext = splitext(name)[1].lower()
-    if ext in ARCHIVE_EXTENSIONS:
-        return True
-    return False
-
-
-def _strip_extras(path):
-    # type: (str) -> Tuple[str, Optional[str]]
-    m = re.match(r'^(.+)(\[[^\]]+\])$', path)
-    extras = None
-    if m:
-        path_no_extras = m.group(1)
-        extras = m.group(2)
-    else:
-        path_no_extras = path
-
-    return path_no_extras, extras
-
-
-def convert_extras(extras):
-    # type: (Optional[str]) -> Set[str]
-    if not extras:
-        return set()
-    return Requirement("placeholder" + extras.lower()).extras
-
-
-def parse_editable(editable_req):
-    # type: (str) -> Tuple[Optional[str], str, Optional[Set[str]]]
-    """Parses an editable requirement into:
-        - a requirement name
-        - an URL
-        - extras
-        - editable options
-    Accepted requirements:
-        svn+http://blahblah@rev#egg=Foobar[baz]&subdirectory=version_subdir
-        .[some_extra]
-    """
-
-    url = editable_req
-
-    # If a file path is specified with extras, strip off the extras.
-    url_no_extras, extras = _strip_extras(url)
-
-    if os.path.isdir(url_no_extras):
-        if not os.path.exists(os.path.join(url_no_extras, 'setup.py')):
-            msg = (
-                'File "setup.py" not found. Directory cannot be installed '
-                'in editable mode: {}'.format(os.path.abspath(url_no_extras))
-            )
-            pyproject_path = make_pyproject_path(url_no_extras)
-            if os.path.isfile(pyproject_path):
-                msg += (
-                    '\n(A "pyproject.toml" file was found, but editable '
-                    'mode currently requires a setup.py based build.)'
-                )
-            raise InstallationError(msg)
-
-        # Treating it as code that has already been checked out
-        url_no_extras = path_to_url(url_no_extras)
-
-    if url_no_extras.lower().startswith('file:'):
-        package_name = Link(url_no_extras).egg_fragment
-        if extras:
-            return (
-                package_name,
-                url_no_extras,
-                Requirement("placeholder" + extras.lower()).extras,
-            )
-        else:
-            return package_name, url_no_extras, None
-
-    for version_control in vcs:
-        if url.lower().startswith('%s:' % version_control):
-            url = '%s+%s' % (version_control, url)
-            break
-
-    if '+' not in url:
-        raise InstallationError(
-            '{} is not a valid editable requirement. '
-            'It should either be a path to a local project or a VCS URL '
-            '(beginning with svn+, git+, hg+, or bzr+).'.format(editable_req)
-        )
-
-    vc_type = url.split('+', 1)[0].lower()
-
-    if not vcs.get_backend(vc_type):
-        error_message = 'For --editable=%s only ' % editable_req + \
-            ', '.join([backend.name + '+URL' for backend in vcs.backends]) + \
-            ' is currently supported'
-        raise InstallationError(error_message)
-
-    package_name = Link(url).egg_fragment
-    if not package_name:
-        raise InstallationError(
-            "Could not detect requirement name for '%s', please specify one "
-            "with #egg=your_package_name" % editable_req
-        )
-    return package_name, url, None
-
-
-def deduce_helpful_msg(req):
-    # type: (str) -> str
-    """Returns helpful msg in case requirements file does not exist,
-    or cannot be parsed.
-
-    :params req: Requirements file path
-    """
-    msg = ""
-    if os.path.exists(req):
-        msg = " It does exist."
-        # Try to parse and check if it is a requirements file.
-        try:
-            with open(req, 'r') as fp:
-                # parse first line only
-                next(parse_requirements(fp.read()))
-                msg += " The argument you provided " + \
-                    "(%s) appears to be a" % (req) + \
-                    " requirements file. If that is the" + \
-                    " case, use the '-r' flag to install" + \
-                    " the packages specified within it."
-        except RequirementParseError:
-            logger.debug("Cannot parse '%s' as requirements \
-            file" % (req), exc_info=True)
-    else:
-        msg += " File '%s' does not exist." % (req)
-    return msg
-
-
-class RequirementParts(object):
-    def __init__(
-            self,
-            requirement,  # type: Optional[Requirement]
-            link,         # type: Optional[Link]
-            markers,      # type: Optional[Marker]
-            extras,       # type: Set[str]
-    ):
-        self.requirement = requirement
-        self.link = link
-        self.markers = markers
-        self.extras = extras
-
-
-def parse_req_from_editable(editable_req):
-    # type: (str) -> RequirementParts
-    name, url, extras_override = parse_editable(editable_req)
-
-    if name is not None:
-        try:
-            req = Requirement(name)
-        except InvalidRequirement:
-            raise InstallationError("Invalid requirement: '%s'" % name)
-    else:
-        req = None
-
-    link = Link(url)
-
-    return RequirementParts(req, link, None, extras_override)
-
-
-# ---- The actual constructors follow ----
-
-
-def install_req_from_editable(
-    editable_req,  # type: str
-    comes_from=None,  # type: Optional[str]
-    use_pep517=None,  # type: Optional[bool]
-    isolated=False,  # type: bool
-    options=None,  # type: Optional[Dict[str, Any]]
-    wheel_cache=None,  # type: Optional[WheelCache]
-    constraint=False  # type: bool
-):
-    # type: (...) -> InstallRequirement
-
-    parts = parse_req_from_editable(editable_req)
-
-    source_dir = parts.link.file_path if parts.link.scheme == 'file' else None
-
-    return InstallRequirement(
-        parts.requirement, comes_from, source_dir=source_dir,
-        editable=True,
-        link=parts.link,
-        constraint=constraint,
-        use_pep517=use_pep517,
-        isolated=isolated,
-        options=options if options else {},
-        wheel_cache=wheel_cache,
-        extras=parts.extras,
-    )
-
-
-def _looks_like_path(name):
-    # type: (str) -> bool
-    """Checks whether the string "looks like" a path on the filesystem.
-
-    This does not check whether the target actually exists, only judge from the
-    appearance.
-
-    Returns true if any of the following conditions is true:
-    * a path separator is found (either os.path.sep or os.path.altsep);
-    * a dot is found (which represents the current directory).
-    """
-    if os.path.sep in name:
-        return True
-    if os.path.altsep is not None and os.path.altsep in name:
-        return True
-    if name.startswith("."):
-        return True
-    return False
-
-
-def _get_url_from_path(path, name):
-    # type: (str, str) -> str
-    """
-    First, it checks whether a provided path is an installable directory
-    (e.g. it has a setup.py). If it is, returns the path.
-
-    If false, check if the path is an archive file (such as a .whl).
-    The function checks if the path is a file. If false, if the path has
-    an @, it will treat it as a PEP 440 URL requirement and return the path.
-    """
-    if _looks_like_path(name) and os.path.isdir(path):
-        if is_installable_dir(path):
-            return path_to_url(path)
-        raise InstallationError(
-            "Directory %r is not installable. Neither 'setup.py' "
-            "nor 'pyproject.toml' found." % name
-        )
-    if not is_archive_file(path):
-        return None
-    if os.path.isfile(path):
-        return path_to_url(path)
-    urlreq_parts = name.split('@', 1)
-    if len(urlreq_parts) >= 2 and not _looks_like_path(urlreq_parts[0]):
-        # If the path contains '@' and the part before it does not look
-        # like a path, try to treat it as a PEP 440 URL req instead.
-        return None
-    logger.warning(
-        'Requirement %r looks like a filename, but the '
-        'file does not exist',
-        name
-    )
-    return path_to_url(path)
-
-
-def parse_req_from_line(name, line_source):
-    # type: (str, Optional[str]) -> RequirementParts
-    if is_url(name):
-        marker_sep = '; '
-    else:
-        marker_sep = ';'
-    if marker_sep in name:
-        name, markers_as_string = name.split(marker_sep, 1)
-        markers_as_string = markers_as_string.strip()
-        if not markers_as_string:
-            markers = None
-        else:
-            markers = Marker(markers_as_string)
-    else:
-        markers = None
-    name = name.strip()
-    req_as_string = None
-    path = os.path.normpath(os.path.abspath(name))
-    link = None
-    extras_as_string = None
-
-    if is_url(name):
-        link = Link(name)
-    else:
-        p, extras_as_string = _strip_extras(path)
-        url = _get_url_from_path(p, name)
-        if url is not None:
-            link = Link(url)
-
-    # it's a local file, dir, or url
-    if link:
-        # Handle relative file URLs
-        if link.scheme == 'file' and re.search(r'\.\./', link.url):
-            link = Link(
-                path_to_url(os.path.normpath(os.path.abspath(link.path))))
-        # wheel file
-        if link.is_wheel:
-            wheel = Wheel(link.filename)  # can raise InvalidWheelFilename
-            req_as_string = "%s==%s" % (wheel.name, wheel.version)
-        else:
-            # set the req to the egg fragment.  when it's not there, this
-            # will become an 'unnamed' requirement
-            req_as_string = link.egg_fragment
-
-    # a requirement specifier
-    else:
-        req_as_string = name
-
-    extras = convert_extras(extras_as_string)
-
-    def with_source(text):
-        # type: (str) -> str
-        if not line_source:
-            return text
-        return '{} (from {})'.format(text, line_source)
-
-    if req_as_string is not None:
-        try:
-            req = Requirement(req_as_string)
-        except InvalidRequirement:
-            if os.path.sep in req_as_string:
-                add_msg = "It looks like a path."
-                add_msg += deduce_helpful_msg(req_as_string)
-            elif ('=' in req_as_string and
-                  not any(op in req_as_string for op in operators)):
-                add_msg = "= is not a valid operator. Did you mean == ?"
-            else:
-                add_msg = ''
-            msg = with_source(
-                'Invalid requirement: {!r}'.format(req_as_string)
-            )
-            if add_msg:
-                msg += '\nHint: {}'.format(add_msg)
-            raise InstallationError(msg)
-    else:
-        req = None
-
-    return RequirementParts(req, link, markers, extras)
-
-
-def install_req_from_line(
-    name,  # type: str
-    comes_from=None,  # type: Optional[Union[str, InstallRequirement]]
-    use_pep517=None,  # type: Optional[bool]
-    isolated=False,  # type: bool
-    options=None,  # type: Optional[Dict[str, Any]]
-    wheel_cache=None,  # type: Optional[WheelCache]
-    constraint=False,  # type: bool
-    line_source=None,  # type: Optional[str]
-):
-    # type: (...) -> InstallRequirement
-    """Creates an InstallRequirement from a name, which might be a
-    requirement, directory containing 'setup.py', filename, or URL.
-
-    :param line_source: An optional string describing where the line is from,
-        for logging purposes in case of an error.
-    """
-    parts = parse_req_from_line(name, line_source)
-
-    return InstallRequirement(
-        parts.requirement, comes_from, link=parts.link, markers=parts.markers,
-        use_pep517=use_pep517, isolated=isolated,
-        options=options if options else {},
-        wheel_cache=wheel_cache,
-        constraint=constraint,
-        extras=parts.extras,
-    )
-
-
-def install_req_from_req_string(
-    req_string,  # type: str
-    comes_from=None,  # type: Optional[InstallRequirement]
-    isolated=False,  # type: bool
-    wheel_cache=None,  # type: Optional[WheelCache]
-    use_pep517=None  # type: Optional[bool]
-):
-    # type: (...) -> InstallRequirement
-    try:
-        req = Requirement(req_string)
-    except InvalidRequirement:
-        raise InstallationError("Invalid requirement: '%s'" % req_string)
-
-    domains_not_allowed = [
-        PyPI.file_storage_domain,
-        TestPyPI.file_storage_domain,
-    ]
-    if (req.url and comes_from and comes_from.link and
-            comes_from.link.netloc in domains_not_allowed):
-        # Explicitly disallow pypi packages that depend on external urls
-        raise InstallationError(
-            "Packages installed from PyPI cannot depend on packages "
-            "which are not also hosted on PyPI.\n"
-            "%s depends on %s " % (comes_from.name, req)
-        )
-
-    return InstallRequirement(
-        req, comes_from, isolated=isolated, wheel_cache=wheel_cache,
-        use_pep517=use_pep517
-    )