Including the venv

lib/python3.8/site-packages/pip/_internal/req/__init__.py

@@ -0,0 +1,78 @@
+from __future__ import absolute_import
+
+import logging
+
+from .req_install import InstallRequirement
+from .req_set import RequirementSet
+from .req_file import parse_requirements
+from pip._internal.utils.logging import indent_log
+from pip._internal.utils.typing import MYPY_CHECK_RUNNING
+
+if MYPY_CHECK_RUNNING:
+    from typing import Any, List, Sequence
+
+__all__ = [
+    "RequirementSet", "InstallRequirement",
+    "parse_requirements", "install_given_reqs",
+]
+
+logger = logging.getLogger(__name__)
+
+
+def install_given_reqs(
+    to_install,  # type: List[InstallRequirement]
+    install_options,  # type: List[str]
+    global_options=(),  # type: Sequence[str]
+    *args,  # type: Any
+    **kwargs  # type: Any
+):
+    # type: (...) -> List[InstallRequirement]
+    """
+    Install everything in the given list.
+
+    (to be called after having downloaded and unpacked the packages)
+    """
+
+    if to_install:
+        logger.info(
+            'Installing collected packages: %s',
+            ', '.join([req.name for req in to_install]),
+        )
+
+    with indent_log():
+        for requirement in to_install:
+            if requirement.conflicts_with:
+                logger.info(
+                    'Found existing installation: %s',
+                    requirement.conflicts_with,
+                )
+                with indent_log():
+                    uninstalled_pathset = requirement.uninstall(
+                        auto_confirm=True
+                    )
+            try:
+                requirement.install(
+                    install_options,
+                    global_options,
+                    *args,
+                    **kwargs
+                )
+            except Exception:
+                should_rollback = (
+                    requirement.conflicts_with and
+                    not requirement.install_succeeded
+                )
+                # if install did not succeed, rollback previous uninstall
+                if should_rollback:
+                    uninstalled_pathset.rollback()
+                raise
+            else:
+                should_commit = (
+                    requirement.conflicts_with and
+                    requirement.install_succeeded
+                )
+                if should_commit:
+                    uninstalled_pathset.commit()
+            requirement.remove_temporary_source()
+
+    return to_install

lib/python3.8/site-packages/pip/_internal/req/constructors.py

@@ -0,0 +1,349 @@
+"""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.
+"""
+
+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.download import is_archive_file, is_url, url_to_path
+from pip._internal.exceptions import InstallationError
+from pip._internal.models.index import PyPI, TestPyPI
+from pip._internal.models.link import Link
+from pip._internal.pyproject import make_pyproject_path
+from pip._internal.req.req_install import InstallRequirement
+from pip._internal.utils.misc import is_installable_dir, path_to_url
+from pip._internal.utils.typing import MYPY_CHECK_RUNNING
+from pip._internal.vcs import vcs
+from pip._internal.wheel import Wheel
+
+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 _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 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
+
+
+# ---- 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
+    name, url, extras_override = parse_editable(editable_req)
+    if url.startswith('file:'):
+        source_dir = url_to_path(url)
+    else:
+        source_dir = None
+
+    if name is not None:
+        try:
+            req = Requirement(name)
+        except InvalidRequirement:
+            raise InstallationError("Invalid requirement: '%s'" % name)
+    else:
+        req = None
+    return InstallRequirement(
+        req, comes_from, source_dir=source_dir,
+        editable=True,
+        link=Link(url),
+        constraint=constraint,
+        use_pep517=use_pep517,
+        isolated=isolated,
+        options=options if options else {},
+        wheel_cache=wheel_cache,
+        extras=extras_override or (),
+    )
+
+
+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.
+    """
+    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)
+        looks_like_dir = os.path.isdir(p) and (
+            os.path.sep in name or
+            (os.path.altsep is not None and os.path.altsep in name) or
+            name.startswith('.')
+        )
+        if looks_like_dir:
+            if not is_installable_dir(p):
+                raise InstallationError(
+                    "Directory %r is not installable. Neither 'setup.py' "
+                    "nor 'pyproject.toml' found." % name
+                )
+            link = Link(path_to_url(p))
+        elif is_archive_file(p):
+            if not os.path.isfile(p):
+                logger.warning(
+                    'Requirement %r looks like a filename, but the '
+                    'file does not exist',
+                    name
+                )
+            link = Link(path_to_url(p))
+
+    # 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
+
+    if extras_as_string:
+        extras = Requirement("placeholder" + extras_as_string.lower()).extras
+    else:
+        extras = ()
+    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 = ''
+            if line_source is None:
+                source = ''
+            else:
+                source = ' (from {})'.format(line_source)
+            msg = (
+                'Invalid requirement: {!r}{}'.format(req_as_string, source)
+            )
+            if add_msg:
+                msg += '\nHint: {}'.format(add_msg)
+            raise InstallationError(msg)
+    else:
+        req = None
+
+    return InstallRequirement(
+        req, comes_from, link=link, markers=markers,
+        use_pep517=use_pep517, isolated=isolated,
+        options=options if options else {},
+        wheel_cache=wheel_cache,
+        constraint=constraint,
+        extras=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
+    )

lib/python3.8/site-packages/pip/_internal/req/req_file.py

@@ -0,0 +1,399 @@
+"""
+Requirements file parsing
+"""
+
+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.download import get_file_content
+from pip._internal.exceptions import 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.typing import MYPY_CHECK_RUNNING
+
+if MYPY_CHECK_RUNNING:
+    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 import PackageFinder
+    from pip._internal.download import PipSession
+
+    ReqFileLines = Iterator[Tuple[int, Text]]
+
+__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.constraints,
+    cmdoptions.editable,
+    cmdoptions.requirements,
+    cmdoptions.no_index,
+    cmdoptions.index_url,
+    cmdoptions.find_links,
+    cmdoptions.extra_index_url,
+    cmdoptions.always_unzip,
+    cmdoptions.no_binary,
+    cmdoptions.only_binary,
+    cmdoptions.pre,
+    cmdoptions.trusted_host,
+    cmdoptions.require_hashes,
+]  # 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]
+
+
+def parse_requirements(
+    filename,  # type: str
+    finder=None,  # type: Optional[PackageFinder]
+    comes_from=None,  # type: Optional[str]
+    options=None,  # type: Optional[optparse.Values]
+    session=None,  # type: Optional[PipSession]
+    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 finder:      Instance of pip.index.PackageFinder.
+    :param comes_from:  Origin description of requirements.
+    :param options:     cli options.
+    :param session:     Instance of pip.download.PipSession.
+    :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.
+    """
+    if session is None:
+        raise TypeError(
+            "parse_requirements() missing 1 required keyword argument: "
+            "'session'"
+        )
+
+    _, content = get_file_content(
+        filename, comes_from=comes_from, session=session
+    )
+
+    lines_enum = preprocess(content, options)
+
+    for line_number, line in lines_enum:
+        req_iter = process_line(line, filename, line_number, finder,
+                                comes_from, options, session, wheel_cache,
+                                use_pep517=use_pep517, constraint=constraint)
+        for req in req_iter:
+            yield req
+
+
+def preprocess(content, options):
+    # type: (Text, Optional[optparse.Values]) -> 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)
+    lines_enum = skip_regex(lines_enum, options)
+    lines_enum = expand_env_variables(lines_enum)
+    return lines_enum
+
+
+def process_line(
+    line,  # type: Text
+    filename,  # type: str
+    line_number,  # type: int
+    finder=None,  # type: Optional[PackageFinder]
+    comes_from=None,  # type: Optional[str]
+    options=None,  # type: Optional[optparse.Values]
+    session=None,  # type: Optional[PipSession]
+    wheel_cache=None,  # type: Optional[WheelCache]
+    use_pep517=None,  # type: Optional[bool]
+    constraint=False,  # type: bool
+):
+    # type: (...) -> Iterator[InstallRequirement]
+    """Process a single 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.
+
+    :param constraint: If True, parsing a constraints file.
+    :param options: OptionParser options that we may update
+    """
+    parser = build_parser(line)
+    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
+
+    # preserve for the nested code path
+    line_comes_from = '%s %s (line %s)' % (
+        '-c' if constraint else '-r', filename, line_number,
+    )
+
+    # yield a line requirement
+    if args_str:
+        isolated = options.isolated_mode if options else False
+        if options:
+            cmdoptions.check_install_build_global(options, opts)
+        # get the options that apply to requirements
+        req_options = {}
+        for dest in SUPPORTED_OPTIONS_REQ_DEST:
+            if dest in opts.__dict__ and opts.__dict__[dest]:
+                req_options[dest] = opts.__dict__[dest]
+        line_source = 'line {} of {}'.format(line_number, filename)
+        yield install_req_from_line(
+            args_str,
+            comes_from=line_comes_from,
+            use_pep517=use_pep517,
+            isolated=isolated,
+            options=req_options,
+            wheel_cache=wheel_cache,
+            constraint=constraint,
+            line_source=line_source,
+        )
+
+    # yield an editable requirement
+    elif opts.editables:
+        isolated = options.isolated_mode if options else False
+        yield install_req_from_editable(
+            opts.editables[0], comes_from=line_comes_from,
+            use_pep517=use_pep517,
+            constraint=constraint, isolated=isolated, wheel_cache=wheel_cache
+        )
+
+    # parse a nested requirements file
+    elif opts.requirements or opts.constraints:
+        if opts.requirements:
+            req_path = opts.requirements[0]
+            nested_constraint = False
+        else:
+            req_path = 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)
+        # TODO: Why not use `comes_from='-r {} (line {})'` here as well?
+        parsed_reqs = parse_requirements(
+            req_path, finder, comes_from, options, session,
+            constraint=nested_constraint, wheel_cache=wheel_cache
+        )
+        for req in parsed_reqs:
+            yield req
+
+    # percolate hash-checking option upward
+    elif opts.require_hashes:
+        options.require_hashes = opts.require_hashes
+
+    # set finder options
+    elif finder:
+        find_links = finder.find_links
+        index_urls = finder.index_urls
+        if opts.index_url:
+            index_urls = [opts.index_url]
+        if opts.no_index is True:
+            index_urls = []
+        if opts.extra_index_urls:
+            index_urls.extend(opts.extra_index_urls)
+        if 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 = opts.find_links[0]
+            req_dir = os.path.dirname(os.path.abspath(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 opts.pre:
+            finder.set_allow_all_prereleases()
+        for host in opts.trusted_hosts or []:
+            source = 'line {} of {}'.format(line_number, filename)
+            finder.add_trusted_host(host, source=source)
+
+
+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
+
+
+def build_parser(line):
+    # type: (Text) -> 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
+        # add offending line
+        msg = 'Invalid requirement: %s\n%s' % (line, msg)
+        raise RequirementsFileParseError(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, options):
+    # type: (ReqFileLines, Optional[optparse.Values]) -> ReqFileLines
+    """
+    Skip lines that match '--skip-requirements-regex' pattern
+
+    Note: the regex pattern is only built once
+    """
+    skip_regex = options.skip_requirements_regex if options else None
+    if skip_regex:
+        pattern = re.compile(skip_regex)
+        lines_enum = filterfalse(lambda e: pattern.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

lib/python3.8/site-packages/pip/_internal/req/req_set.py

@@ -0,0 +1,193 @@
+from __future__ import absolute_import
+
+import logging
+from collections import OrderedDict
+
+from pip._internal.exceptions import InstallationError
+from pip._internal.utils.logging import indent_log
+from pip._internal.utils.typing import MYPY_CHECK_RUNNING
+from pip._internal.wheel import Wheel
+
+if MYPY_CHECK_RUNNING:
+    from typing import Dict, Iterable, List, Optional, Tuple
+    from pip._internal.req.req_install import InstallRequirement
+
+
+logger = logging.getLogger(__name__)
+
+
+class RequirementSet(object):
+
+    def __init__(self, require_hashes=False, check_supported_wheels=True):
+        # type: (bool, bool) -> None
+        """Create a RequirementSet.
+        """
+
+        self.requirements = OrderedDict()  # type: Dict[str, InstallRequirement]  # noqa: E501
+        self.require_hashes = require_hashes
+        self.check_supported_wheels = check_supported_wheels
+
+        # Mapping of alias: real_name
+        self.requirement_aliases = {}  # type: Dict[str, str]
+        self.unnamed_requirements = []  # type: List[InstallRequirement]
+        self.successfully_downloaded = []  # type: List[InstallRequirement]
+        self.reqs_to_cleanup = []  # type: List[InstallRequirement]
+
+    def __str__(self):
+        # type: () -> str
+        reqs = [req for req in self.requirements.values()
+                if not req.comes_from]
+        reqs.sort(key=lambda req: req.name.lower())
+        return ' '.join([str(req.req) for req in reqs])
+
+    def __repr__(self):
+        # type: () -> str
+        reqs = [req for req in self.requirements.values()]
+        reqs.sort(key=lambda req: req.name.lower())
+        reqs_str = ', '.join([str(req.req) for req in reqs])
+        return ('<%s object; %d requirement(s): %s>'
+                % (self.__class__.__name__, len(reqs), reqs_str))
+
+    def add_requirement(
+        self,
+        install_req,  # type: InstallRequirement
+        parent_req_name=None,  # type: Optional[str]
+        extras_requested=None  # type: Optional[Iterable[str]]
+    ):
+        # type: (...) -> Tuple[List[InstallRequirement], Optional[InstallRequirement]]  # noqa: E501
+        """Add install_req as a requirement to install.
+
+        :param parent_req_name: The name of the requirement that needed this
+            added. The name is used because when multiple unnamed requirements
+            resolve to the same name, we could otherwise end up with dependency
+            links that point outside the Requirements set. parent_req must
+            already be added. Note that None implies that this is a user
+            supplied requirement, vs an inferred one.
+        :param extras_requested: an iterable of extras used to evaluate the
+            environment markers.
+        :return: Additional requirements to scan. That is either [] if
+            the requirement is not applicable, or [install_req] if the
+            requirement is applicable and has just been added.
+        """
+        name = install_req.name
+
+        # If the markers do not match, ignore this requirement.
+        if not install_req.match_markers(extras_requested):
+            logger.info(
+                "Ignoring %s: markers '%s' don't match your environment",
+                name, install_req.markers,
+            )
+            return [], None
+
+        # If the wheel is not supported, raise an error.
+        # Should check this after filtering out based on environment markers to
+        # allow specifying different wheels based on the environment/OS, in a
+        # single requirements file.
+        if install_req.link and install_req.link.is_wheel:
+            wheel = Wheel(install_req.link.filename)
+            if self.check_supported_wheels and not wheel.supported():
+                raise InstallationError(
+                    "%s is not a supported wheel on this platform." %
+                    wheel.filename
+                )
+
+        # This next bit is really a sanity check.
+        assert install_req.is_direct == (parent_req_name is None), (
+            "a direct req shouldn't have a parent and also, "
+            "a non direct req should have a parent"
+        )
+
+        # Unnamed requirements are scanned again and the requirement won't be
+        # added as a dependency until after scanning.
+        if not name:
+            # url or path requirement w/o an egg fragment
+            self.unnamed_requirements.append(install_req)
+            return [install_req], None
+
+        try:
+            existing_req = self.get_requirement(name)
+        except KeyError:
+            existing_req = None
+
+        has_conflicting_requirement = (
+            parent_req_name is None and
+            existing_req and
+            not existing_req.constraint and
+            existing_req.extras == install_req.extras and
+            existing_req.req.specifier != install_req.req.specifier
+        )
+        if has_conflicting_requirement:
+            raise InstallationError(
+                "Double requirement given: %s (already in %s, name=%r)"
+                % (install_req, existing_req, name)
+            )
+
+        # When no existing requirement exists, add the requirement as a
+        # dependency and it will be scanned again after.
+        if not existing_req:
+            self.requirements[name] = install_req
+            # FIXME: what about other normalizations?  E.g., _ vs. -?
+            if name.lower() != name:
+                self.requirement_aliases[name.lower()] = name
+            # We'd want to rescan this requirements later
+            return [install_req], install_req
+
+        # Assume there's no need to scan, and that we've already
+        # encountered this for scanning.
+        if install_req.constraint or not existing_req.constraint:
+            return [], existing_req
+
+        does_not_satisfy_constraint = (
+            install_req.link and
+            not (
+                existing_req.link and
+                install_req.link.path == existing_req.link.path
+            )
+        )
+        if does_not_satisfy_constraint:
+            self.reqs_to_cleanup.append(install_req)
+            raise InstallationError(
+                "Could not satisfy constraints for '%s': "
+                "installation from path or url cannot be "
+                "constrained to a version" % name,
+            )
+        # If we're now installing a constraint, mark the existing
+        # object for real installation.
+        existing_req.constraint = False
+        existing_req.extras = tuple(sorted(
+            set(existing_req.extras) | set(install_req.extras)
+        ))
+        logger.debug(
+            "Setting %s extras to: %s",
+            existing_req, existing_req.extras,
+        )
+        # Return the existing requirement for addition to the parent and
+        # scanning again.
+        return [existing_req], existing_req
+
+    def has_requirement(self, project_name):
+        # type: (str) -> bool
+        name = project_name.lower()
+        if (name in self.requirements and
+           not self.requirements[name].constraint or
+           name in self.requirement_aliases and
+           not self.requirements[self.requirement_aliases[name]].constraint):
+            return True
+        return False
+
+    def get_requirement(self, project_name):
+        # type: (str) -> InstallRequirement
+        for name in project_name, project_name.lower():
+            if name in self.requirements:
+                return self.requirements[name]
+            if name in self.requirement_aliases:
+                return self.requirements[self.requirement_aliases[name]]
+        raise KeyError("No project with the name %r" % project_name)
+
+    def cleanup_files(self):
+        # type: () -> None
+        """Clean up files, remove builds."""
+        logger.debug('Cleaning up...')
+        with indent_log():
+            for req in self.reqs_to_cleanup:
+                req.remove_temporary_source()

lib/python3.8/site-packages/pip/_internal/req/req_tracker.py

@@ -0,0 +1,96 @@
+from __future__ import absolute_import
+
+import contextlib
+import errno
+import hashlib
+import logging
+import os
+
+from pip._internal.utils.temp_dir import TempDirectory
+from pip._internal.utils.typing import MYPY_CHECK_RUNNING
+
+if MYPY_CHECK_RUNNING:
+    from types import TracebackType
+    from typing import Iterator, Optional, Set, Type
+    from pip._internal.req.req_install import InstallRequirement
+    from pip._internal.models.link import Link
+
+logger = logging.getLogger(__name__)
+
+
+class RequirementTracker(object):
+
+    def __init__(self):
+        # type: () -> None
+        self._root = os.environ.get('PIP_REQ_TRACKER')
+        if self._root is None:
+            self._temp_dir = TempDirectory(delete=False, kind='req-tracker')
+            self._temp_dir.create()
+            self._root = os.environ['PIP_REQ_TRACKER'] = self._temp_dir.path
+            logger.debug('Created requirements tracker %r', self._root)
+        else:
+            self._temp_dir = None
+            logger.debug('Re-using requirements tracker %r', self._root)
+        self._entries = set()  # type: Set[InstallRequirement]
+
+    def __enter__(self):
+        # type: () -> RequirementTracker
+        return self
+
+    def __exit__(
+        self,
+        exc_type,  # type: Optional[Type[BaseException]]
+        exc_val,  # type: Optional[BaseException]
+        exc_tb  # type: Optional[TracebackType]
+    ):
+        # type: (...) -> None
+        self.cleanup()
+
+    def _entry_path(self, link):
+        # type: (Link) -> str
+        hashed = hashlib.sha224(link.url_without_fragment.encode()).hexdigest()
+        return os.path.join(self._root, hashed)
+
+    def add(self, req):
+        # type: (InstallRequirement) -> None
+        link = req.link
+        info = str(req)
+        entry_path = self._entry_path(link)
+        try:
+            with open(entry_path) as fp:
+                # Error, these's already a build in progress.
+                raise LookupError('%s is already being built: %s'
+                                  % (link, fp.read()))
+        except IOError as e:
+            if e.errno != errno.ENOENT:
+                raise
+            assert req not in self._entries
+            with open(entry_path, 'w') as fp:
+                fp.write(info)
+            self._entries.add(req)
+            logger.debug('Added %s to build tracker %r', req, self._root)
+
+    def remove(self, req):
+        # type: (InstallRequirement) -> None
+        link = req.link
+        self._entries.remove(req)
+        os.unlink(self._entry_path(link))
+        logger.debug('Removed %s from build tracker %r', req, self._root)
+
+    def cleanup(self):
+        # type: () -> None
+        for req in set(self._entries):
+            self.remove(req)
+        remove = self._temp_dir is not None
+        if remove:
+            self._temp_dir.cleanup()
+        logger.debug('%s build tracker %r',
+                     'Removed' if remove else 'Cleaned',
+                     self._root)
+
+    @contextlib.contextmanager
+    def track(self, req):
+        # type: (InstallRequirement) -> Iterator[None]
+        self.add(req)
+        yield
+        self.remove(req)

lib/python3.8/site-packages/pip/_internal/req/req_uninstall.py

@@ -0,0 +1,633 @@
+from __future__ import absolute_import
+
+import csv
+import functools
+import logging
+import os
+import sys
+import sysconfig
+
+from pip._vendor import pkg_resources
+
+from pip._internal.exceptions import UninstallationError
+from pip._internal.locations import bin_py, bin_user
+from pip._internal.utils.compat import WINDOWS, cache_from_source, uses_pycache
+from pip._internal.utils.logging import indent_log
+from pip._internal.utils.misc import (
+    FakeFile, ask, dist_in_usersite, dist_is_local, egg_link_path, is_local,
+    normalize_path, renames, rmtree,
+)
+from pip._internal.utils.temp_dir import AdjacentTempDirectory, TempDirectory
+from pip._internal.utils.typing import MYPY_CHECK_RUNNING
+
+if MYPY_CHECK_RUNNING:
+    from typing import (
+        Any, Callable, Dict, Iterable, Iterator, List, Optional, Set, Tuple,
+    )
+    from pip._vendor.pkg_resources import Distribution
+
+logger = logging.getLogger(__name__)
+
+
+def _script_names(dist, script_name, is_gui):
+    # type: (Distribution, str, bool) -> List[str]
+    """Create the fully qualified name of the files created by
+    {console,gui}_scripts for the given ``dist``.
+    Returns the list of file names
+    """
+    if dist_in_usersite(dist):
+        bin_dir = bin_user
+    else:
+        bin_dir = bin_py
+    exe_name = os.path.join(bin_dir, script_name)
+    paths_to_remove = [exe_name]
+    if WINDOWS:
+        paths_to_remove.append(exe_name + '.exe')
+        paths_to_remove.append(exe_name + '.exe.manifest')
+        if is_gui:
+            paths_to_remove.append(exe_name + '-script.pyw')
+        else:
+            paths_to_remove.append(exe_name + '-script.py')
+    return paths_to_remove
+
+
+def _unique(fn):
+    # type: (Callable) -> Callable[..., Iterator[Any]]
+    @functools.wraps(fn)
+    def unique(*args, **kw):
+        # type: (Any, Any) -> Iterator[Any]
+        seen = set()  # type: Set[Any]
+        for item in fn(*args, **kw):
+            if item not in seen:
+                seen.add(item)
+                yield item
+    return unique
+
+
+@_unique
+def uninstallation_paths(dist):
+    # type: (Distribution) -> Iterator[str]
+    """
+    Yield all the uninstallation paths for dist based on RECORD-without-.py[co]
+
+    Yield paths to all the files in RECORD. For each .py file in RECORD, add
+    the .pyc and .pyo in the same directory.
+
+    UninstallPathSet.add() takes care of the __pycache__ .py[co].
+    """
+    r = csv.reader(FakeFile(dist.get_metadata_lines('RECORD')))
+    for row in r:
+        path = os.path.join(dist.location, row[0])
+        yield path
+        if path.endswith('.py'):
+            dn, fn = os.path.split(path)
+            base = fn[:-3]
+            path = os.path.join(dn, base + '.pyc')
+            yield path
+            path = os.path.join(dn, base + '.pyo')
+            yield path
+
+
+def compact(paths):
+    # type: (Iterable[str]) -> Set[str]
+    """Compact a path set to contain the minimal number of paths
+    necessary to contain all paths in the set. If /a/path/ and
+    /a/path/to/a/file.txt are both in the set, leave only the
+    shorter path."""
+
+    sep = os.path.sep
+    short_paths = set()  # type: Set[str]
+    for path in sorted(paths, key=len):
+        should_skip = any(
+            path.startswith(shortpath.rstrip("*")) and
+            path[len(shortpath.rstrip("*").rstrip(sep))] == sep
+            for shortpath in short_paths
+        )
+        if not should_skip:
+            short_paths.add(path)
+    return short_paths
+
+
+def compress_for_rename(paths):
+    # type: (Iterable[str]) -> Set[str]
+    """Returns a set containing the paths that need to be renamed.
+
+    This set may include directories when the original sequence of paths
+    included every file on disk.
+    """
+    case_map = dict((os.path.normcase(p), p) for p in paths)
+    remaining = set(case_map)
+    unchecked = sorted(set(os.path.split(p)[0]
+                           for p in case_map.values()), key=len)
+    wildcards = set()  # type: Set[str]
+
+    def norm_join(*a):
+        # type: (str) -> str
+        return os.path.normcase(os.path.join(*a))
+
+    for root in unchecked:
+        if any(os.path.normcase(root).startswith(w)
+               for w in wildcards):
+            # This directory has already been handled.
+            continue
+
+        all_files = set()  # type: Set[str]
+        all_subdirs = set()  # type: Set[str]
+        for dirname, subdirs, files in os.walk(root):
+            all_subdirs.update(norm_join(root, dirname, d)
+                               for d in subdirs)
+            all_files.update(norm_join(root, dirname, f)
+                             for f in files)
+        # If all the files we found are in our remaining set of files to
+        # remove, then remove them from the latter set and add a wildcard
+        # for the directory.
+        if not (all_files - remaining):
+            remaining.difference_update(all_files)
+            wildcards.add(root + os.sep)
+
+    return set(map(case_map.__getitem__, remaining)) | wildcards
+
+
+def compress_for_output_listing(paths):
+    # type: (Iterable[str]) -> Tuple[Set[str], Set[str]]
+    """Returns a tuple of 2 sets of which paths to display to user
+
+    The first set contains paths that would be deleted. Files of a package
+    are not added and the top-level directory of the package has a '*' added
+    at the end - to signify that all it's contents are removed.
+
+    The second set contains files that would have been skipped in the above
+    folders.
+    """
+
+    will_remove = set(paths)
+    will_skip = set()
+
+    # Determine folders and files
+    folders = set()
+    files = set()
+    for path in will_remove:
+        if path.endswith(".pyc"):
+            continue
+        if path.endswith("__init__.py") or ".dist-info" in path:
+            folders.add(os.path.dirname(path))
+        files.add(path)
+
+    # probably this one https://github.com/python/mypy/issues/390
+    _normcased_files = set(map(os.path.normcase, files))  # type: ignore
+
+    folders = compact(folders)
+
+    # This walks the tree using os.walk to not miss extra folders
+    # that might get added.
+    for folder in folders:
+        for dirpath, _, dirfiles in os.walk(folder):
+            for fname in dirfiles:
+                if fname.endswith(".pyc"):
+                    continue
+
+                file_ = os.path.join(dirpath, fname)
+                if (os.path.isfile(file_) and
+                        os.path.normcase(file_) not in _normcased_files):
+                    # We are skipping this file. Add it to the set.
+                    will_skip.add(file_)
+
+    will_remove = files | {
+        os.path.join(folder, "*") for folder in folders
+    }
+
+    return will_remove, will_skip
+
+
+class StashedUninstallPathSet(object):
+    """A set of file rename operations to stash files while
+    tentatively uninstalling them."""
+    def __init__(self):
+        # type: () -> None
+        # Mapping from source file root to [Adjacent]TempDirectory
+        # for files under that directory.
+        self._save_dirs = {}  # type: Dict[str, TempDirectory]
+        # (old path, new path) tuples for each move that may need
+        # to be undone.
+        self._moves = []  # type: List[Tuple[str, str]]
+
+    def _get_directory_stash(self, path):
+        # type: (str) -> str
+        """Stashes a directory.
+
+        Directories are stashed adjacent to their original location if
+        possible, or else moved/copied into the user's temp dir."""
+
+        try:
+            save_dir = AdjacentTempDirectory(path)  # type: TempDirectory
+            save_dir.create()
+        except OSError:
+            save_dir = TempDirectory(kind="uninstall")
+            save_dir.create()
+        self._save_dirs[os.path.normcase(path)] = save_dir
+
+        return save_dir.path
+
+    def _get_file_stash(self, path):
+        # type: (str) -> str
+        """Stashes a file.
+
+        If no root has been provided, one will be created for the directory
+        in the user's temp directory."""
+        path = os.path.normcase(path)
+        head, old_head = os.path.dirname(path), None
+        save_dir = None
+
+        while head != old_head:
+            try:
+                save_dir = self._save_dirs[head]
+                break
+            except KeyError:
+                pass
+            head, old_head = os.path.dirname(head), head
+        else:
+            # Did not find any suitable root
+            head = os.path.dirname(path)
+            save_dir = TempDirectory(kind='uninstall')
+            save_dir.create()
+            self._save_dirs[head] = save_dir
+
+        relpath = os.path.relpath(path, head)
+        if relpath and relpath != os.path.curdir:
+            return os.path.join(save_dir.path, relpath)
+        return save_dir.path
+
+    def stash(self, path):
+        # type: (str) -> str
+        """Stashes the directory or file and returns its new location.
+        """
+        if os.path.isdir(path):
+            new_path = self._get_directory_stash(path)
+        else:
+            new_path = self._get_file_stash(path)
+
+        self._moves.append((path, new_path))
+        if os.path.isdir(path) and os.path.isdir(new_path):
+            # If we're moving a directory, we need to
+            # remove the destination first or else it will be
+            # moved to inside the existing directory.
+            # We just created new_path ourselves, so it will
+            # be removable.
+            os.rmdir(new_path)
+        renames(path, new_path)
+        return new_path
+
+    def commit(self):
+        # type: () -> None
+        """Commits the uninstall by removing stashed files."""
+        for _, save_dir in self._save_dirs.items():
+            save_dir.cleanup()
+        self._moves = []
+        self._save_dirs = {}
+
+    def rollback(self):
+        # type: () -> None
+        """Undoes the uninstall by moving stashed files back."""
+        for p in self._moves:
+            logging.info("Moving to %s\n from %s", *p)
+
+        for new_path, path in self._moves:
+            try:
+                logger.debug('Replacing %s from %s', new_path, path)
+                if os.path.isfile(new_path):
+                    os.unlink(new_path)
+                elif os.path.isdir(new_path):
+                    rmtree(new_path)
+                renames(path, new_path)
+            except OSError as ex:
+                logger.error("Failed to restore %s", new_path)
+                logger.debug("Exception: %s", ex)
+
+        self.commit()
+
+    @property
+    def can_rollback(self):
+        # type: () -> bool
+        return bool(self._moves)
+
+
+class UninstallPathSet(object):
+    """A set of file paths to be removed in the uninstallation of a
+    requirement."""
+    def __init__(self, dist):
+        # type: (Distribution) -> None
+        self.paths = set()  # type: Set[str]
+        self._refuse = set()  # type: Set[str]
+        self.pth = {}  # type: Dict[str, UninstallPthEntries]
+        self.dist = dist
+        self._moved_paths = StashedUninstallPathSet()
+
+    def _permitted(self, path):
+        # type: (str) -> bool
+        """
+        Return True if the given path is one we are permitted to
+        remove/modify, False otherwise.
+
+        """
+        return is_local(path)
+
+    def add(self, path):
+        # type: (str) -> None
+        head, tail = os.path.split(path)
+
+        # we normalize the head to resolve parent directory symlinks, but not
+        # the tail, since we only want to uninstall symlinks, not their targets
+        path = os.path.join(normalize_path(head), os.path.normcase(tail))
+
+        if not os.path.exists(path):
+            return
+        if self._permitted(path):
+            self.paths.add(path)
+        else:
+            self._refuse.add(path)
+
+        # __pycache__ files can show up after 'installed-files.txt' is created,
+        # due to imports
+        if os.path.splitext(path)[1] == '.py' and uses_pycache:
+            self.add(cache_from_source(path))
+
+    def add_pth(self, pth_file, entry):
+        # type: (str, str) -> None
+        pth_file = normalize_path(pth_file)
+        if self._permitted(pth_file):
+            if pth_file not in self.pth:
+                self.pth[pth_file] = UninstallPthEntries(pth_file)
+            self.pth[pth_file].add(entry)
+        else:
+            self._refuse.add(pth_file)
+
+    def remove(self, auto_confirm=False, verbose=False):
+        # type: (bool, bool) -> None
+        """Remove paths in ``self.paths`` with confirmation (unless
+        ``auto_confirm`` is True)."""
+
+        if not self.paths:
+            logger.info(
+                "Can't uninstall '%s'. No files were found to uninstall.",
+                self.dist.project_name,
+            )
+            return
+
+        dist_name_version = (
+            self.dist.project_name + "-" + self.dist.version
+        )
+        logger.info('Uninstalling %s:', dist_name_version)
+
+        with indent_log():
+            if auto_confirm or self._allowed_to_proceed(verbose):
+                moved = self._moved_paths
+
+                for_rename = compress_for_rename(self.paths)
+
+                for path in sorted(compact(for_rename)):
+                    moved.stash(path)
+                    logger.debug('Removing file or directory %s', path)
+
+                for pth in self.pth.values():
+                    pth.remove()
+
+                logger.info('Successfully uninstalled %s', dist_name_version)
+
+    def _allowed_to_proceed(self, verbose):
+        # type: (bool) -> bool
+        """Display which files would be deleted and prompt for confirmation
+        """
+
+        def _display(msg, paths):
+            # type: (str, Iterable[str]) -> None
+            if not paths:
+                return
+
+            logger.info(msg)
+            with indent_log():
+                for path in sorted(compact(paths)):
+                    logger.info(path)
+
+        if not verbose:
+            will_remove, will_skip = compress_for_output_listing(self.paths)
+        else:
+            # In verbose mode, display all the files that are going to be
+            # deleted.
+            will_remove = set(self.paths)
+            will_skip = set()
+
+        _display('Would remove:', will_remove)
+        _display('Would not remove (might be manually added):', will_skip)
+        _display('Would not remove (outside of prefix):', self._refuse)
+        if verbose:
+            _display('Will actually move:', compress_for_rename(self.paths))
+
+        return ask('Proceed (y/n)? ', ('y', 'n')) == 'y'
+
+    def rollback(self):
+        # type: () -> None
+        """Rollback the changes previously made by remove()."""
+        if not self._moved_paths.can_rollback:
+            logger.error(
+                "Can't roll back %s; was not uninstalled",
+                self.dist.project_name,
+            )
+            return
+        logger.info('Rolling back uninstall of %s', self.dist.project_name)
+        self._moved_paths.rollback()
+        for pth in self.pth.values():
+            pth.rollback()
+
+    def commit(self):
+        # type: () -> None
+        """Remove temporary save dir: rollback will no longer be possible."""
+        self._moved_paths.commit()
+
+    @classmethod
+    def from_dist(cls, dist):
+        # type: (Distribution) -> UninstallPathSet
+        dist_path = normalize_path(dist.location)
+        if not dist_is_local(dist):
+            logger.info(
+                "Not uninstalling %s at %s, outside environment %s",
+                dist.key,
+                dist_path,
+                sys.prefix,
+            )
+            return cls(dist)
+
+        if dist_path in {p for p in {sysconfig.get_path("stdlib"),
+                                     sysconfig.get_path("platstdlib")}
+                         if p}:
+            logger.info(
+                "Not uninstalling %s at %s, as it is in the standard library.",
+                dist.key,
+                dist_path,
+            )
+            return cls(dist)
+
+        paths_to_remove = cls(dist)
+        develop_egg_link = egg_link_path(dist)
+        develop_egg_link_egg_info = '{}.egg-info'.format(
+            pkg_resources.to_filename(dist.project_name))
+        egg_info_exists = dist.egg_info and os.path.exists(dist.egg_info)
+        # Special case for distutils installed package
+        distutils_egg_info = getattr(dist._provider, 'path', None)
+
+        # Uninstall cases order do matter as in the case of 2 installs of the
+        # same package, pip needs to uninstall the currently detected version
+        if (egg_info_exists and dist.egg_info.endswith('.egg-info') and
+                not dist.egg_info.endswith(develop_egg_link_egg_info)):
+            # if dist.egg_info.endswith(develop_egg_link_egg_info), we
+            # are in fact in the develop_egg_link case
+            paths_to_remove.add(dist.egg_info)
+            if dist.has_metadata('installed-files.txt'):
+                for installed_file in dist.get_metadata(
+                        'installed-files.txt').splitlines():
+                    path = os.path.normpath(
+                        os.path.join(dist.egg_info, installed_file)
+                    )
+                    paths_to_remove.add(path)
+            # FIXME: need a test for this elif block
+            # occurs with --single-version-externally-managed/--record outside
+            # of pip
+            elif dist.has_metadata('top_level.txt'):
+                if dist.has_metadata('namespace_packages.txt'):
+                    namespaces = dist.get_metadata('namespace_packages.txt')
+                else:
+                    namespaces = []
+                for top_level_pkg in [
+                        p for p
+                        in dist.get_metadata('top_level.txt').splitlines()
+                        if p and p not in namespaces]:
+                    path = os.path.join(dist.location, top_level_pkg)
+                    paths_to_remove.add(path)
+                    paths_to_remove.add(path + '.py')
+                    paths_to_remove.add(path + '.pyc')
+                    paths_to_remove.add(path + '.pyo')
+
+        elif distutils_egg_info:
+            raise UninstallationError(
+                "Cannot uninstall {!r}. It is a distutils installed project "
+                "and thus we cannot accurately determine which files belong "
+                "to it which would lead to only a partial uninstall.".format(
+                    dist.project_name,
+                )
+            )
+
+        elif dist.location.endswith('.egg'):
+            # package installed by easy_install
+            # We cannot match on dist.egg_name because it can slightly vary
+            # i.e. setuptools-0.6c11-py2.6.egg vs setuptools-0.6rc11-py2.6.egg
+            paths_to_remove.add(dist.location)
+            easy_install_egg = os.path.split(dist.location)[1]
+            easy_install_pth = os.path.join(os.path.dirname(dist.location),
+                                            'easy-install.pth')
+            paths_to_remove.add_pth(easy_install_pth, './' + easy_install_egg)
+
+        elif egg_info_exists and dist.egg_info.endswith('.dist-info'):
+            for path in uninstallation_paths(dist):
+                paths_to_remove.add(path)
+
+        elif develop_egg_link:
+            # develop egg
+            with open(develop_egg_link, 'r') as fh:
+                link_pointer = os.path.normcase(fh.readline().strip())
+            assert (link_pointer == dist.location), (
+                'Egg-link %s does not match installed location of %s '
+                '(at %s)' % (link_pointer, dist.project_name, dist.location)
+            )
+            paths_to_remove.add(develop_egg_link)
+            easy_install_pth = os.path.join(os.path.dirname(develop_egg_link),
+                                            'easy-install.pth')
+            paths_to_remove.add_pth(easy_install_pth, dist.location)
+
+        else:
+            logger.debug(
+                'Not sure how to uninstall: %s - Check: %s',
+                dist, dist.location,
+            )
+
+        # find distutils scripts= scripts
+        if dist.has_metadata('scripts') and dist.metadata_isdir('scripts'):
+            for script in dist.metadata_listdir('scripts'):
+                if dist_in_usersite(dist):
+                    bin_dir = bin_user
+                else:
+                    bin_dir = bin_py
+                paths_to_remove.add(os.path.join(bin_dir, script))
+                if WINDOWS:
+                    paths_to_remove.add(os.path.join(bin_dir, script) + '.bat')
+
+        # find console_scripts
+        _scripts_to_remove = []
+        console_scripts = dist.get_entry_map(group='console_scripts')
+        for name in console_scripts.keys():
+            _scripts_to_remove.extend(_script_names(dist, name, False))
+        # find gui_scripts
+        gui_scripts = dist.get_entry_map(group='gui_scripts')
+        for name in gui_scripts.keys():
+            _scripts_to_remove.extend(_script_names(dist, name, True))
+
+        for s in _scripts_to_remove:
+            paths_to_remove.add(s)
+
+        return paths_to_remove
+
+
+class UninstallPthEntries(object):
+    def __init__(self, pth_file):
+        # type: (str) -> None
+        if not os.path.isfile(pth_file):
+            raise UninstallationError(
+                "Cannot remove entries from nonexistent file %s" % pth_file
+            )
+        self.file = pth_file
+        self.entries = set()  # type: Set[str]
+        self._saved_lines = None  # type: Optional[List[bytes]]
+
+    def add(self, entry):
+        # type: (str) -> None
+        entry = os.path.normcase(entry)
+        # On Windows, os.path.normcase converts the entry to use
+        # backslashes.  This is correct for entries that describe absolute
+        # paths outside of site-packages, but all the others use forward
+        # slashes.
+        if WINDOWS and not os.path.splitdrive(entry)[0]:
+            entry = entry.replace('\\', '/')
+        self.entries.add(entry)
+
+    def remove(self):
+        # type: () -> None
+        logger.debug('Removing pth entries from %s:', self.file)
+        with open(self.file, 'rb') as fh:
+            # windows uses '\r\n' with py3k, but uses '\n' with py2.x
+            lines = fh.readlines()
+            self._saved_lines = lines
+        if any(b'\r\n' in line for line in lines):
+            endline = '\r\n'
+        else:
+            endline = '\n'
+        # handle missing trailing newline
+        if lines and not lines[-1].endswith(endline.encode("utf-8")):
+            lines[-1] = lines[-1] + endline.encode("utf-8")
+        for entry in self.entries:
+            try:
+                logger.debug('Removing entry: %s', entry)
+                lines.remove((entry + endline).encode("utf-8"))
+            except ValueError:
+                pass
+        with open(self.file, 'wb') as fh:
+            fh.writelines(lines)
+
+    def rollback(self):
+        # type: () -> bool
+        if self._saved_lines is None:
+            logger.error(
+                'Cannot roll back changes to %s, none were made', self.file
+            )
+            return False
+        logger.debug('Rolling %s back to previous state', self.file)
+        with open(self.file, 'wb') as fh:
+            fh.writelines(self._saved_lines)
+        return True