major changes

env/lib/python3.5/site-packages/pip/_internal/cache.py

+"""Cache Management
+"""
+
+# The following comment should be removed at some point in the future.
+# mypy: strict-optional=False
+
+import hashlib
+import json
+import logging
+import os
+
+from pip._vendor.packaging.tags import interpreter_name, interpreter_version
+from pip._vendor.packaging.utils import canonicalize_name
+
+from pip._internal.exceptions import InvalidWheelFilename
+from pip._internal.models.link import Link
+from pip._internal.models.wheel import Wheel
+from pip._internal.utils.temp_dir import TempDirectory
+from pip._internal.utils.typing import MYPY_CHECK_RUNNING
+from pip._internal.utils.urls import path_to_url
+
+if MYPY_CHECK_RUNNING:
+    from typing import Optional, Set, List, Any, Dict
+
+    from pip._vendor.packaging.tags import Tag
+
+    from pip._internal.models.format_control import FormatControl
+
+logger = logging.getLogger(__name__)
+
+
+def _hash_dict(d):
+    # type: (Dict[str, str]) -> str
+    """Return a stable sha224 of a dictionary."""
+    s = json.dumps(d, sort_keys=True, separators=(",", ":"), ensure_ascii=True)
+    return hashlib.sha224(s.encode("ascii")).hexdigest()
+
+
+class Cache(object):
+    """An abstract class - provides cache directories for data from links
+
+
+        :param cache_dir: The root of the cache.
+        :param format_control: An object of FormatControl class to limit
+            binaries being read from the cache.
+        :param allowed_formats: which formats of files the cache should store.
+            ('binary' and 'source' are the only allowed values)
+    """
+
+    def __init__(self, cache_dir, format_control, allowed_formats):
+        # type: (str, FormatControl, Set[str]) -> None
+        super(Cache, self).__init__()
+        assert not cache_dir or os.path.isabs(cache_dir)
+        self.cache_dir = cache_dir or None
+        self.format_control = format_control
+        self.allowed_formats = allowed_formats
+
+        _valid_formats = {"source", "binary"}
+        assert self.allowed_formats.union(_valid_formats) == _valid_formats
+
+    def _get_cache_path_parts_legacy(self, link):
+        # type: (Link) -> List[str]
+        """Get parts of part that must be os.path.joined with cache_dir
+
+        Legacy cache key (pip < 20) for compatibility with older caches.
+        """
+
+        # We want to generate an url to use as our cache key, we don't want to
+        # just re-use the URL because it might have other items in the fragment
+        # and we don't care about those.
+        key_parts = [link.url_without_fragment]
+        if link.hash_name is not None and link.hash is not None:
+            key_parts.append("=".join([link.hash_name, link.hash]))
+        key_url = "#".join(key_parts)
+
+        # Encode our key url with sha224, we'll use this because it has similar
+        # security properties to sha256, but with a shorter total output (and
+        # thus less secure). However the differences don't make a lot of
+        # difference for our use case here.
+        hashed = hashlib.sha224(key_url.encode()).hexdigest()
+
+        # We want to nest the directories some to prevent having a ton of top
+        # level directories where we might run out of sub directories on some
+        # FS.
+        parts = [hashed[:2], hashed[2:4], hashed[4:6], hashed[6:]]
+
+        return parts
+
+    def _get_cache_path_parts(self, link):
+        # type: (Link) -> List[str]
+        """Get parts of part that must be os.path.joined with cache_dir
+        """
+
+        # We want to generate an url to use as our cache key, we don't want to
+        # just re-use the URL because it might have other items in the fragment
+        # and we don't care about those.
+        key_parts = {"url": link.url_without_fragment}
+        if link.hash_name is not None and link.hash is not None:
+            key_parts[link.hash_name] = link.hash
+        if link.subdirectory_fragment:
+            key_parts["subdirectory"] = link.subdirectory_fragment
+
+        # Include interpreter name, major and minor version in cache key
+        # to cope with ill-behaved sdists that build a different wheel
+        # depending on the python version their setup.py is being run on,
+        # and don't encode the difference in compatibility tags.
+        # https://github.com/pypa/pip/issues/7296
+        key_parts["interpreter_name"] = interpreter_name()
+        key_parts["interpreter_version"] = interpreter_version()
+
+        # Encode our key url with sha224, we'll use this because it has similar
+        # security properties to sha256, but with a shorter total output (and
+        # thus less secure). However the differences don't make a lot of
+        # difference for our use case here.
+        hashed = _hash_dict(key_parts)
+
+        # We want to nest the directories some to prevent having a ton of top
+        # level directories where we might run out of sub directories on some
+        # FS.
+        parts = [hashed[:2], hashed[2:4], hashed[4:6], hashed[6:]]
+
+        return parts
+
+    def _get_candidates(self, link, canonical_package_name):
+        # type: (Link, Optional[str]) -> List[Any]
+        can_not_cache = (
+            not self.cache_dir or
+            not canonical_package_name or
+            not link
+        )
+        if can_not_cache:
+            return []
+
+        formats = self.format_control.get_allowed_formats(
+            canonical_package_name
+        )
+        if not self.allowed_formats.intersection(formats):
+            return []
+
+        candidates = []
+        path = self.get_path_for_link(link)
+        if os.path.isdir(path):
+            for candidate in os.listdir(path):
+                candidates.append((candidate, path))
+        # TODO remove legacy path lookup in pip>=21
+        legacy_path = self.get_path_for_link_legacy(link)
+        if os.path.isdir(legacy_path):
+            for candidate in os.listdir(legacy_path):
+                candidates.append((candidate, legacy_path))
+        return candidates
+
+    def get_path_for_link_legacy(self, link):
+        # type: (Link) -> str
+        raise NotImplementedError()
+
+    def get_path_for_link(self, link):
+        # type: (Link) -> str
+        """Return a directory to store cached items in for link.
+        """
+        raise NotImplementedError()
+
+    def get(
+        self,
+        link,            # type: Link
+        package_name,    # type: Optional[str]
+        supported_tags,  # type: List[Tag]
+    ):
+        # type: (...) -> Link
+        """Returns a link to a cached item if it exists, otherwise returns the
+        passed link.
+        """
+        raise NotImplementedError()
+
+    def cleanup(self):
+        # type: () -> None
+        pass
+
+
+class SimpleWheelCache(Cache):
+    """A cache of wheels for future installs.
+    """
+
+    def __init__(self, cache_dir, format_control):
+        # type: (str, FormatControl) -> None
+        super(SimpleWheelCache, self).__init__(
+            cache_dir, format_control, {"binary"}
+        )
+
+    def get_path_for_link_legacy(self, link):
+        # type: (Link) -> str
+        parts = self._get_cache_path_parts_legacy(link)
+        return os.path.join(self.cache_dir, "wheels", *parts)
+
+    def get_path_for_link(self, link):
+        # type: (Link) -> str
+        """Return a directory to store cached wheels for link
+
+        Because there are M wheels for any one sdist, we provide a directory
+        to cache them in, and then consult that directory when looking up
+        cache hits.
+
+        We only insert things into the cache if they have plausible version
+        numbers, so that we don't contaminate the cache with things that were
+        not unique. E.g. ./package might have dozens of installs done for it
+        and build a version of 0.0...and if we built and cached a wheel, we'd
+        end up using the same wheel even if the source has been edited.
+
+        :param link: The link of the sdist for which this will cache wheels.
+        """
+        parts = self._get_cache_path_parts(link)
+
+        # Store wheels within the root cache_dir
+        return os.path.join(self.cache_dir, "wheels", *parts)
+
+    def get(
+        self,
+        link,            # type: Link
+        package_name,    # type: Optional[str]
+        supported_tags,  # type: List[Tag]
+    ):
+        # type: (...) -> Link
+        candidates = []
+
+        if not package_name:
+            return link
+
+        canonical_package_name = canonicalize_name(package_name)
+        for wheel_name, wheel_dir in self._get_candidates(
+            link, canonical_package_name
+        ):
+            try:
+                wheel = Wheel(wheel_name)
+            except InvalidWheelFilename:
+                continue
+            if canonicalize_name(wheel.name) != canonical_package_name:
+                logger.debug(
+                    "Ignoring cached wheel {} for {} as it "
+                    "does not match the expected distribution name {}.".format(
+                        wheel_name, link, package_name
+                    )
+                )
+                continue
+            if not wheel.supported(supported_tags):
+                # Built for a different python/arch/etc
+                continue
+            candidates.append(
+                (
+                    wheel.support_index_min(supported_tags),
+                    wheel_name,
+                    wheel_dir,
+                )
+            )
+
+        if not candidates:
+            return link
+
+        _, wheel_name, wheel_dir = min(candidates)
+        return Link(path_to_url(os.path.join(wheel_dir, wheel_name)))
+
+
+class EphemWheelCache(SimpleWheelCache):
+    """A SimpleWheelCache that creates it's own temporary cache directory
+    """
+
+    def __init__(self, format_control):
+        # type: (FormatControl) -> None
+        self._temp_dir = TempDirectory(kind="ephem-wheel-cache")
+
+        super(EphemWheelCache, self).__init__(
+            self._temp_dir.path, format_control
+        )
+
+    def cleanup(self):
+        # type: () -> None
+        self._temp_dir.cleanup()
+
+
+class WheelCache(Cache):
+    """Wraps EphemWheelCache and SimpleWheelCache into a single Cache
+
+    This Cache allows for gracefully degradation, using the ephem wheel cache
+    when a certain link is not found in the simple wheel cache first.
+    """
+
+    def __init__(self, cache_dir, format_control):
+        # type: (str, FormatControl) -> None
+        super(WheelCache, self).__init__(
+            cache_dir, format_control, {'binary'}
+        )
+        self._wheel_cache = SimpleWheelCache(cache_dir, format_control)
+        self._ephem_cache = EphemWheelCache(format_control)
+
+    def get_path_for_link_legacy(self, link):
+        # type: (Link) -> str
+        return self._wheel_cache.get_path_for_link_legacy(link)
+
+    def get_path_for_link(self, link):
+        # type: (Link) -> str
+        return self._wheel_cache.get_path_for_link(link)
+
+    def get_ephem_path_for_link(self, link):
+        # type: (Link) -> str
+        return self._ephem_cache.get_path_for_link(link)
+
+    def get(
+        self,
+        link,            # type: Link
+        package_name,    # type: Optional[str]
+        supported_tags,  # type: List[Tag]
+    ):
+        # type: (...) -> Link
+        retval = self._wheel_cache.get(
+            link=link,
+            package_name=package_name,
+            supported_tags=supported_tags,
+        )
+        if retval is not link:
+            return retval
+
+        return self._ephem_cache.get(
+            link=link,
+            package_name=package_name,
+            supported_tags=supported_tags,
+        )
+
+    def cleanup(self):
+        # type: () -> None
+        self._wheel_cache.cleanup()
+        self._ephem_cache.cleanup()

env/lib/python3.5/site-packages/pip/_internal/cli/__init__.py

+"""Subpackage containing all of pip's command line interface related code
+"""
+
+# This file intentionally does not import submodules

env/lib/python3.5/site-packages/pip/_internal/cli/autocompletion.py

+"""Logic that powers autocompletion installed by ``pip completion``.
+"""
+
+import optparse
+import os
+import sys
+from itertools import chain
+
+from pip._internal.cli.main_parser import create_main_parser
+from pip._internal.commands import commands_dict, create_command
+from pip._internal.utils.misc import get_installed_distributions
+from pip._internal.utils.typing import MYPY_CHECK_RUNNING
+
+if MYPY_CHECK_RUNNING:
+    from typing import Any, Iterable, List, Optional
+
+
+def autocomplete():
+    # type: () -> None
+    """Entry Point for completion of main and subcommand options.
+    """
+    # Don't complete if user hasn't sourced bash_completion file.
+    if 'PIP_AUTO_COMPLETE' not in os.environ:
+        return
+    cwords = os.environ['COMP_WORDS'].split()[1:]
+    cword = int(os.environ['COMP_CWORD'])
+    try:
+        current = cwords[cword - 1]
+    except IndexError:
+        current = ''
+
+    parser = create_main_parser()
+    subcommands = list(commands_dict)
+    options = []
+
+    # subcommand
+    subcommand_name = None  # type: Optional[str]
+    for word in cwords:
+        if word in subcommands:
+            subcommand_name = word
+            break
+    # subcommand options
+    if subcommand_name is not None:
+        # special case: 'help' subcommand has no options
+        if subcommand_name == 'help':
+            sys.exit(1)
+        # special case: list locally installed dists for show and uninstall
+        should_list_installed = (
+            subcommand_name in ['show', 'uninstall'] and
+            not current.startswith('-')
+        )
+        if should_list_installed:
+            installed = []
+            lc = current.lower()
+            for dist in get_installed_distributions(local_only=True):
+                if dist.key.startswith(lc) and dist.key not in cwords[1:]:
+                    installed.append(dist.key)
+            # if there are no dists installed, fall back to option completion
+            if installed:
+                for dist in installed:
+                    print(dist)
+                sys.exit(1)
+
+        subcommand = create_command(subcommand_name)
+
+        for opt in subcommand.parser.option_list_all:
+            if opt.help != optparse.SUPPRESS_HELP:
+                for opt_str in opt._long_opts + opt._short_opts:
+                    options.append((opt_str, opt.nargs))
+
+        # filter out previously specified options from available options
+        prev_opts = [x.split('=')[0] for x in cwords[1:cword - 1]]
+        options = [(x, v) for (x, v) in options if x not in prev_opts]
+        # filter options by current input
+        options = [(k, v) for k, v in options if k.startswith(current)]
+        # get completion type given cwords and available subcommand options
+        completion_type = get_path_completion_type(
+            cwords, cword, subcommand.parser.option_list_all,
+        )
+        # get completion files and directories if ``completion_type`` is
+        # ``<file>``, ``<dir>`` or ``<path>``
+        if completion_type:
+            paths = auto_complete_paths(current, completion_type)
+            options = [(path, 0) for path in paths]
+        for option in options:
+            opt_label = option[0]
+            # append '=' to options which require args
+            if option[1] and option[0][:2] == "--":
+                opt_label += '='
+            print(opt_label)
+    else:
+        # show main parser options only when necessary
+
+        opts = [i.option_list for i in parser.option_groups]
+        opts.append(parser.option_list)
+        flattened_opts = chain.from_iterable(opts)
+        if current.startswith('-'):
+            for opt in flattened_opts:
+                if opt.help != optparse.SUPPRESS_HELP:
+                    subcommands += opt._long_opts + opt._short_opts
+        else:
+            # get completion type given cwords and all available options
+            completion_type = get_path_completion_type(cwords, cword,
+                                                       flattened_opts)
+            if completion_type:
+                subcommands = list(auto_complete_paths(current,
+                                                       completion_type))
+
+        print(' '.join([x for x in subcommands if x.startswith(current)]))
+    sys.exit(1)
+
+
+def get_path_completion_type(cwords, cword, opts):
+    # type: (List[str], int, Iterable[Any]) -> Optional[str]
+    """Get the type of path completion (``file``, ``dir``, ``path`` or None)
+
+    :param cwords: same as the environmental variable ``COMP_WORDS``
+    :param cword: same as the environmental variable ``COMP_CWORD``
+    :param opts: The available options to check
+    :return: path completion type (``file``, ``dir``, ``path`` or None)
+    """
+    if cword < 2 or not cwords[cword - 2].startswith('-'):
+        return None
+    for opt in opts:
+        if opt.help == optparse.SUPPRESS_HELP:
+            continue
+        for o in str(opt).split('/'):
+            if cwords[cword - 2].split('=')[0] == o:
+                if not opt.metavar or any(
+                        x in ('path', 'file', 'dir')
+                        for x in opt.metavar.split('/')):
+                    return opt.metavar
+    return None
+
+
+def auto_complete_paths(current, completion_type):
+    # type: (str, str) -> Iterable[str]
+    """If ``completion_type`` is ``file`` or ``path``, list all regular files
+    and directories starting with ``current``; otherwise only list directories
+    starting with ``current``.
+
+    :param current: The word to be completed
+    :param completion_type: path completion type(`file`, `path` or `dir`)i
+    :return: A generator of regular files and/or directories
+    """
+    directory, filename = os.path.split(current)
+    current_path = os.path.abspath(directory)
+    # Don't complete paths if they can't be accessed
+    if not os.access(current_path, os.R_OK):
+        return
+    filename = os.path.normcase(filename)
+    # list all files that start with ``filename``
+    file_list = (x for x in os.listdir(current_path)
+                 if os.path.normcase(x).startswith(filename))
+    for f in file_list:
+        opt = os.path.join(current_path, f)
+        comp_file = os.path.normcase(os.path.join(directory, f))
+        # complete regular files when there is not ``<dir>`` after option
+        # complete directories when there is ``<file>``, ``<path>`` or
+        # ``<dir>``after option
+        if completion_type != 'dir' and os.path.isfile(opt):
+            yield comp_file
+        elif os.path.isdir(opt):
+            yield os.path.join(comp_file, '')

env/lib/python3.5/site-packages/pip/_internal/cli/base_command.py

+"""Base Command class, and related routines"""
+
+from __future__ import absolute_import, print_function
+
+import logging
+import logging.config
+import optparse
+import os
+import platform
+import sys
+import traceback
+
+from pip._internal.cli import cmdoptions
+from pip._internal.cli.command_context import CommandContextMixIn
+from pip._internal.cli.parser import (
+    ConfigOptionParser,
+    UpdatingDefaultsHelpFormatter,
+)
+from pip._internal.cli.status_codes import (
+    ERROR,
+    PREVIOUS_BUILD_DIR_ERROR,
+    SUCCESS,
+    UNKNOWN_ERROR,
+    VIRTUALENV_NOT_FOUND,
+)
+from pip._internal.exceptions import (
+    BadCommand,
+    CommandError,
+    InstallationError,
+    PreviousBuildDirError,
+    UninstallationError,
+)
+from pip._internal.utils.deprecation import deprecated
+from pip._internal.utils.filesystem import check_path_owner
+from pip._internal.utils.logging import BrokenStdoutLoggingError, setup_logging
+from pip._internal.utils.misc import get_prog, normalize_path
+from pip._internal.utils.temp_dir import global_tempdir_manager
+from pip._internal.utils.typing import MYPY_CHECK_RUNNING
+from pip._internal.utils.virtualenv import running_under_virtualenv
+
+if MYPY_CHECK_RUNNING:
+    from typing import List, Tuple, Any
+    from optparse import Values
+
+__all__ = ['Command']
+
+logger = logging.getLogger(__name__)
+
+
+class Command(CommandContextMixIn):
+    usage = None  # type: str
+    ignore_require_venv = False  # type: bool
+
+    def __init__(self, name, summary, isolated=False):
+        # type: (str, str, bool) -> None
+        super(Command, self).__init__()
+        parser_kw = {
+            'usage': self.usage,
+            'prog': '%s %s' % (get_prog(), name),
+            'formatter': UpdatingDefaultsHelpFormatter(),
+            'add_help_option': False,
+            'name': name,
+            'description': self.__doc__,
+            'isolated': isolated,
+        }
+
+        self.name = name
+        self.summary = summary
+        self.parser = ConfigOptionParser(**parser_kw)
+
+        # Commands should add options to this option group
+        optgroup_name = '%s Options' % self.name.capitalize()
+        self.cmd_opts = optparse.OptionGroup(self.parser, optgroup_name)
+
+        # Add the general options
+        gen_opts = cmdoptions.make_option_group(
+            cmdoptions.general_group,
+            self.parser,
+        )
+        self.parser.add_option_group(gen_opts)
+
+    def handle_pip_version_check(self, options):
+        # type: (Values) -> None
+        """
+        This is a no-op so that commands by default do not do the pip version
+        check.
+        """
+        # Make sure we do the pip version check if the index_group options
+        # are present.
+        assert not hasattr(options, 'no_index')
+
+    def run(self, options, args):
+        # type: (Values, List[Any]) -> Any
+        raise NotImplementedError
+
+    def parse_args(self, args):
+        # type: (List[str]) -> Tuple[Any, Any]
+        # factored out for testability
+        return self.parser.parse_args(args)
+
+    def main(self, args):
+        # type: (List[str]) -> int
+        try:
+            with self.main_context():
+                return self._main(args)
+        finally:
+            logging.shutdown()
+
+    def _main(self, args):
+        # type: (List[str]) -> int
+        # Intentionally set as early as possible so globally-managed temporary
+        # directories are available to the rest of the code.
+        self.enter_context(global_tempdir_manager())
+
+        options, args = self.parse_args(args)
+
+        # Set verbosity so that it can be used elsewhere.
+        self.verbosity = options.verbose - options.quiet
+
+        level_number = setup_logging(
+            verbosity=self.verbosity,
+            no_color=options.no_color,
+            user_log_file=options.log,
+        )
+
+        if (
+            sys.version_info[:2] == (2, 7) and
+            not options.no_python_version_warning
+        ):
+            message = (
+                "A future version of pip will drop support for Python 2.7. "
+                "More details about Python 2 support in pip, can be found at "
+                "https://pip.pypa.io/en/latest/development/release-process/#python-2-support"  # noqa
+            )
+            if platform.python_implementation() == "CPython":
+                message = (
+                    "Python 2.7 reached the end of its life on January "
+                    "1st, 2020. Please upgrade your Python as Python 2.7 "
+                    "is no longer maintained. "
+                ) + message
+            deprecated(message, replacement=None, gone_in=None)
+
+        if options.skip_requirements_regex:
+            deprecated(
+                "--skip-requirements-regex is unsupported and will be removed",
+                replacement=(
+                    "manage requirements/constraints files explicitly, "
+                    "possibly generating them from metadata"
+                ),
+                gone_in="20.1",
+                issue=7297,
+            )
+
+        # TODO: Try to get these passing down from the command?
+        #       without resorting to os.environ to hold these.
+        #       This also affects isolated builds and it should.
+
+        if options.no_input:
+            os.environ['PIP_NO_INPUT'] = '1'
+
+        if options.exists_action:
+            os.environ['PIP_EXISTS_ACTION'] = ' '.join(options.exists_action)
+
+        if options.require_venv and not self.ignore_require_venv:
+            # If a venv is required check if it can really be found
+            if not running_under_virtualenv():
+                logger.critical(
+                    'Could not find an activated virtualenv (required).'
+                )
+                sys.exit(VIRTUALENV_NOT_FOUND)
+
+        if options.cache_dir:
+            options.cache_dir = normalize_path(options.cache_dir)
+            if not check_path_owner(options.cache_dir):
+                logger.warning(
+                    "The directory '%s' or its parent directory is not owned "
+                    "or is not writable by the current user. The cache "
+                    "has been disabled. Check the permissions and owner of "
+                    "that directory. If executing pip with sudo, you may want "
+                    "sudo's -H flag.",
+                    options.cache_dir,
+                )
+                options.cache_dir = None
+
+        try:
+            status = self.run(options, args)
+            # FIXME: all commands should return an exit status
+            # and when it is done, isinstance is not needed anymore
+            if isinstance(status, int):
+                return status
+        except PreviousBuildDirError as exc:
+            logger.critical(str(exc))
+            logger.debug('Exception information:', exc_info=True)
+
+            return PREVIOUS_BUILD_DIR_ERROR
+        except (InstallationError, UninstallationError, BadCommand) as exc:
+            logger.critical(str(exc))
+            logger.debug('Exception information:', exc_info=True)
+
+            return ERROR
+        except CommandError as exc:
+            logger.critical('%s', exc)
+            logger.debug('Exception information:', exc_info=True)
+
+            return ERROR
+        except BrokenStdoutLoggingError:
+            # Bypass our logger and write any remaining messages to stderr
+            # because stdout no longer works.
+            print('ERROR: Pipe to stdout was broken', file=sys.stderr)
+            if level_number <= logging.DEBUG:
+                traceback.print_exc(file=sys.stderr)
+
+            return ERROR
+        except KeyboardInterrupt:
+            logger.critical('Operation cancelled by user')
+            logger.debug('Exception information:', exc_info=True)
+
+            return ERROR
+        except BaseException:
+            logger.critical('Exception:', exc_info=True)
+
+            return UNKNOWN_ERROR
+        finally:
+            self.handle_pip_version_check(options)
+
+        return SUCCESS

env/lib/python3.5/site-packages/pip/_internal/cli/cmdoptions.py

+"""
+shared options and groups
+
+The principle here is to define options once, but *not* instantiate them
+globally. One reason being that options with action='append' can carry state
+between parses. pip parses general options twice internally, and shouldn't
+pass on state. To be consistent, all options will follow this design.
+"""
+
+# The following comment should be removed at some point in the future.
+# mypy: strict-optional=False
+
+from __future__ import absolute_import
+
+import logging
+import os
+import textwrap
+import warnings
+from distutils.util import strtobool
+from functools import partial
+from optparse import SUPPRESS_HELP, Option, OptionGroup
+from textwrap import dedent
+
+from pip._internal.exceptions import CommandError
+from pip._internal.locations import USER_CACHE_DIR, get_src_prefix
+from pip._internal.models.format_control import FormatControl
+from pip._internal.models.index import PyPI
+from pip._internal.models.target_python import TargetPython
+from pip._internal.utils.hashes import STRONG_HASHES
+from pip._internal.utils.typing import MYPY_CHECK_RUNNING
+from pip._internal.utils.ui import BAR_TYPES
+
+if MYPY_CHECK_RUNNING:
+    from typing import Any, Callable, Dict, Optional, Tuple
+    from optparse import OptionParser, Values
+    from pip._internal.cli.parser import ConfigOptionParser
+
+logger = logging.getLogger(__name__)
+
+
+def raise_option_error(parser, option, msg):
+    # type: (OptionParser, Option, str) -> None
+    """
+    Raise an option parsing error using parser.error().
+
+    Args:
+      parser: an OptionParser instance.
+      option: an Option instance.
+      msg: the error text.
+    """
+    msg = '{} error: {}'.format(option, msg)
+    msg = textwrap.fill(' '.join(msg.split()))
+    parser.error(msg)
+
+
+def make_option_group(group, parser):
+    # type: (Dict[str, Any], ConfigOptionParser) -> OptionGroup
+    """
+    Return an OptionGroup object
+    group  -- assumed to be dict with 'name' and 'options' keys
+    parser -- an optparse Parser
+    """
+    option_group = OptionGroup(parser, group['name'])
+    for option in group['options']:
+        option_group.add_option(option())
+    return option_group
+
+
+def check_install_build_global(options, check_options=None):
+    # type: (Values, Optional[Values]) -> None
+    """Disable wheels if per-setup.py call options are set.
+
+    :param options: The OptionParser options to update.
+    :param check_options: The options to check, if not supplied defaults to
+        options.
+    """
+    if check_options is None:
+        check_options = options
+
+    def getname(n):
+        # type: (str) -> Optional[Any]
+        return getattr(check_options, n, None)
+    names = ["build_options", "global_options", "install_options"]
+    if any(map(getname, names)):
+        control = options.format_control
+        control.disallow_binaries()
+        warnings.warn(
+            'Disabling all use of wheels due to the use of --build-option '
+            '/ --global-option / --install-option.', stacklevel=2,
+        )
+
+
+def check_dist_restriction(options, check_target=False):
+    # type: (Values, bool) -> None
+    """Function for determining if custom platform options are allowed.
+
+    :param options: The OptionParser options.
+    :param check_target: Whether or not to check if --target is being used.
+    """
+    dist_restriction_set = any([
+        options.python_version,
+        options.platform,
+        options.abi,
+        options.implementation,
+    ])
+
+    binary_only = FormatControl(set(), {':all:'})
+    sdist_dependencies_allowed = (
+        options.format_control != binary_only and
+        not options.ignore_dependencies
+    )
+
+    # Installations or downloads using dist restrictions must not combine
+    # source distributions and dist-specific wheels, as they are not
+    # guaranteed to be locally compatible.
+    if dist_restriction_set and sdist_dependencies_allowed:
+        raise CommandError(
+            "When restricting platform and interpreter constraints using "
+            "--python-version, --platform, --abi, or --implementation, "
+            "either --no-deps must be set, or --only-binary=:all: must be "
+            "set and --no-binary must not be set (or must be set to "
+            ":none:)."
+        )
+
+    if check_target:
+        if dist_restriction_set and not options.target_dir:
+            raise CommandError(
+                "Can not use any platform or abi specific options unless "
+                "installing via '--target'"
+            )
+
+
+def _path_option_check(option, opt, value):
+    # type: (Option, str, str) -> str
+    return os.path.expanduser(value)
+
+
+class PipOption(Option):
+    TYPES = Option.TYPES + ("path",)
+    TYPE_CHECKER = Option.TYPE_CHECKER.copy()
+    TYPE_CHECKER["path"] = _path_option_check
+
+
+###########
+# options #
+###########
+
+help_ = partial(
+    Option,
+    '-h', '--help',
+    dest='help',
+    action='help',
+    help='Show help.',
+)  # type: Callable[..., Option]
+
+isolated_mode = partial(
+    Option,
+    "--isolated",
+    dest="isolated_mode",
+    action="store_true",
+    default=False,
+    help=(
+        "Run pip in an isolated mode, ignoring environment variables and user "
+        "configuration."
+    ),
+)  # type: Callable[..., Option]
+
+require_virtualenv = partial(
+    Option,
+    # Run only if inside a virtualenv, bail if not.
+    '--require-virtualenv', '--require-venv',
+    dest='require_venv',
+    action='store_true',
+    default=False,
+    help=SUPPRESS_HELP
+)  # type: Callable[..., Option]
+
+verbose = partial(
+    Option,
+    '-v', '--verbose',
+    dest='verbose',
+    action='count',
+    default=0,
+    help='Give more output. Option is additive, and can be used up to 3 times.'
+)  # type: Callable[..., Option]
+
+no_color = partial(
+    Option,
+    '--no-color',
+    dest='no_color',
+    action='store_true',
+    default=False,
+    help="Suppress colored output",
+)  # type: Callable[..., Option]
+
+version = partial(
+    Option,
+    '-V', '--version',
+    dest='version',
+    action='store_true',
+    help='Show version and exit.',
+)  # type: Callable[..., Option]
+
+quiet = partial(
+    Option,
+    '-q', '--quiet',
+    dest='quiet',
+    action='count',
+    default=0,
+    help=(
+        'Give less output. Option is additive, and can be used up to 3'
+        ' times (corresponding to WARNING, ERROR, and CRITICAL logging'
+        ' levels).'
+    ),
+)  # type: Callable[..., Option]
+
+progress_bar = partial(
+    Option,
+    '--progress-bar',
+    dest='progress_bar',
+    type='choice',
+    choices=list(BAR_TYPES.keys()),
+    default='on',
+    help=(
+        'Specify type of progress to be displayed [' +
+        '|'.join(BAR_TYPES.keys()) + '] (default: %default)'
+    ),
+)  # type: Callable[..., Option]
+
+log = partial(
+    PipOption,
+    "--log", "--log-file", "--local-log",
+    dest="log",
+    metavar="path",
+    type="path",
+    help="Path to a verbose appending log."
+)  # type: Callable[..., Option]
+
+no_input = partial(
+    Option,
+    # Don't ask for input
+    '--no-input',
+    dest='no_input',
+    action='store_true',
+    default=False,
+    help=SUPPRESS_HELP
+)  # type: Callable[..., Option]
+
+proxy = partial(
+    Option,
+    '--proxy',
+    dest='proxy',
+    type='str',
+    default='',
+    help="Specify a proxy in the form [user:passwd@]proxy.server:port."
+)  # type: Callable[..., Option]
+
+retries = partial(
+    Option,
+    '--retries',
+    dest='retries',
+    type='int',
+    default=5,
+    help="Maximum number of retries each connection should attempt "
+         "(default %default times).",
+)  # type: Callable[..., Option]
+
+timeout = partial(
+    Option,
+    '--timeout', '--default-timeout',
+    metavar='sec',
+    dest='timeout',
+    type='float',
+    default=15,
+    help='Set the socket timeout (default %default seconds).',
+)  # type: Callable[..., Option]
+
+skip_requirements_regex = partial(
+    Option,
+    # A regex to be used to skip requirements
+    '--skip-requirements-regex',
+    dest='skip_requirements_regex',
+    type='str',
+    default='',
+    help=SUPPRESS_HELP,
+)  # type: Callable[..., Option]
+
+
+def exists_action():
+    # type: () -> Option
+    return Option(
+        # Option when path already exist
+        '--exists-action',
+        dest='exists_action',
+        type='choice',
+        choices=['s', 'i', 'w', 'b', 'a'],
+        default=[],
+        action='append',
+        metavar='action',
+        help="Default action when a path already exists: "
+             "(s)witch, (i)gnore, (w)ipe, (b)ackup, (a)bort.",
+    )
+
+
+cert = partial(
+    PipOption,
+    '--cert',
+    dest='cert',
+    type='path',
+    metavar='path',
+    help="Path to alternate CA bundle.",
+)  # type: Callable[..., Option]
+
+client_cert = partial(
+    PipOption,
+    '--client-cert',
+    dest='client_cert',
+    type='path',
+    default=None,
+    metavar='path',
+    help="Path to SSL client certificate, a single file containing the "
+         "private key and the certificate in PEM format.",
+)  # type: Callable[..., Option]
+
+index_url = partial(
+    Option,
+    '-i', '--index-url', '--pypi-url',
+    dest='index_url',
+    metavar='URL',
+    default=PyPI.simple_url,
+    help="Base URL of the Python Package Index (default %default). "
+         "This should point to a repository compliant with PEP 503 "
+         "(the simple repository API) or a local directory laid out "
+         "in the same format.",
+)  # type: Callable[..., Option]
+
+
+def extra_index_url():
+    # type: () -> Option
+    return Option(
+        '--extra-index-url',
+        dest='extra_index_urls',
+        metavar='URL',
+        action='append',
+        default=[],
+        help="Extra URLs of package indexes to use in addition to "
+             "--index-url. Should follow the same rules as "
+             "--index-url.",
+    )
+
+
+no_index = partial(
+    Option,
+    '--no-index',
+    dest='no_index',
+    action='store_true',
+    default=False,
+    help='Ignore package index (only looking at --find-links URLs instead).',
+)  # type: Callable[..., Option]
+
+
+def find_links():
+    # type: () -> Option
+    return Option(
+        '-f', '--find-links',
+        dest='find_links',
+        action='append',
+        default=[],
+        metavar='url',
+        help="If a url or path to an html file, then parse for links to "
+             "archives. If a local path or file:// url that's a directory, "
+             "then look for archives in the directory listing.",
+    )
+
+
+def trusted_host():
+    # type: () -> Option
+    return Option(
+        "--trusted-host",
+        dest="trusted_hosts",
+        action="append",
+        metavar="HOSTNAME",
+        default=[],
+        help="Mark this host or host:port pair as trusted, even though it "
+             "does not have valid or any HTTPS.",
+    )
+
+
+def constraints():
+    # type: () -> Option
+    return Option(
+        '-c', '--constraint',
+        dest='constraints',
+        action='append',
+        default=[],
+        metavar='file',
+        help='Constrain versions using the given constraints file. '
+        'This option can be used multiple times.'
+    )
+
+
+def requirements():
+    # type: () -> Option
+    return Option(
+        '-r', '--requirement',
+        dest='requirements',
+        action='append',
+        default=[],
+        metavar='file',
+        help='Install from the given requirements file. '
+        'This option can be used multiple times.'
+    )
+
+
+def editable():
+    # type: () -> Option
+    return Option(
+        '-e', '--editable',
+        dest='editables',
+        action='append',
+        default=[],
+        metavar='path/url',
+        help=('Install a project in editable mode (i.e. setuptools '
+              '"develop mode") from a local project path or a VCS url.'),
+    )
+
+
+def _handle_src(option, opt_str, value, parser):
+    # type: (Option, str, str, OptionParser) -> None
+    value = os.path.abspath(value)
+    setattr(parser.values, option.dest, value)
+
+
+src = partial(
+    PipOption,
+    '--src', '--source', '--source-dir', '--source-directory',
+    dest='src_dir',
+    type='path',
+    metavar='dir',
+    default=get_src_prefix(),
+    action='callback',
+    callback=_handle_src,
+    help='Directory to check out editable projects into. '
+    'The default in a virtualenv is "<venv path>/src". '
+    'The default for global installs is "<current dir>/src".'
+)  # type: Callable[..., Option]
+
+
+def _get_format_control(values, option):
+    # type: (Values, Option) -> Any
+    """Get a format_control object."""
+    return getattr(values, option.dest)
+
+
+def _handle_no_binary(option, opt_str, value, parser):
+    # type: (Option, str, str, OptionParser) -> None
+    existing = _get_format_control(parser.values, option)
+    FormatControl.handle_mutual_excludes(
+        value, existing.no_binary, existing.only_binary,
+    )
+
+
+def _handle_only_binary(option, opt_str, value, parser):
+    # type: (Option, str, str, OptionParser) -> None
+    existing = _get_format_control(parser.values, option)
+    FormatControl.handle_mutual_excludes(
+        value, existing.only_binary, existing.no_binary,
+    )
+
+
+def no_binary():
+    # type: () -> Option
+    format_control = FormatControl(set(), set())
+    return Option(
+        "--no-binary", dest="format_control", action="callback",
+        callback=_handle_no_binary, type="str",
+        default=format_control,
+        help="Do not use binary packages. Can be supplied multiple times, and "
+             "each time adds to the existing value. Accepts either :all: to "
+             "disable all binary packages, :none: to empty the set, or one or "
+             "more package names with commas between them (no colons). Note "
+             "that some packages are tricky to compile and may fail to "
+             "install when this option is used on them.",
+    )
+
+
+def only_binary():
+    # type: () -> Option
+    format_control = FormatControl(set(), set())
+    return Option(
+        "--only-binary", dest="format_control", action="callback",
+        callback=_handle_only_binary, type="str",
+        default=format_control,
+        help="Do not use source packages. Can be supplied multiple times, and "
+             "each time adds to the existing value. Accepts either :all: to "
+             "disable all source packages, :none: to empty the set, or one or "
+             "more package names with commas between them. Packages without "
+             "binary distributions will fail to install when this option is "
+             "used on them.",
+    )
+
+
+platform = partial(
+    Option,
+    '--platform',
+    dest='platform',
+    metavar='platform',
+    default=None,
+    help=("Only use wheels compatible with <platform>. "
+          "Defaults to the platform of the running system."),
+)  # type: Callable[..., Option]
+
+
+# This was made a separate function for unit-testing purposes.
+def _convert_python_version(value):
+    # type: (str) -> Tuple[Tuple[int, ...], Optional[str]]
+    """
+    Convert a version string like "3", "37", or "3.7.3" into a tuple of ints.
+
+    :return: A 2-tuple (version_info, error_msg), where `error_msg` is
+        non-None if and only if there was a parsing error.
+    """
+    if not value:
+        # The empty string is the same as not providing a value.
+        return (None, None)
+
+    parts = value.split('.')
+    if len(parts) > 3:
+        return ((), 'at most three version parts are allowed')
+
+    if len(parts) == 1:
+        # Then we are in the case of "3" or "37".
+        value = parts[0]
+        if len(value) > 1:
+            parts = [value[0], value[1:]]
+
+    try:
+        version_info = tuple(int(part) for part in parts)
+    except ValueError:
+        return ((), 'each version part must be an integer')
+
+    return (version_info, None)
+
+
+def _handle_python_version(option, opt_str, value, parser):
+    # type: (Option, str, str, OptionParser) -> None
+    """
+    Handle a provided --python-version value.
+    """
+    version_info, error_msg = _convert_python_version(value)
+    if error_msg is not None:
+        msg = (
+            'invalid --python-version value: {!r}: {}'.format(
+                value, error_msg,
+            )
+        )
+        raise_option_error(parser, option=option, msg=msg)
+
+    parser.values.python_version = version_info
+
+
+python_version = partial(
+    Option,
+    '--python-version',
+    dest='python_version',
+    metavar='python_version',
+    action='callback',
+    callback=_handle_python_version, type='str',
+    default=None,
+    help=dedent("""\
+    The Python interpreter version to use for wheel and "Requires-Python"
+    compatibility checks. Defaults to a version derived from the running
+    interpreter. The version can be specified using up to three dot-separated
+    integers (e.g. "3" for 3.0.0, "3.7" for 3.7.0, or "3.7.3"). A major-minor
+    version can also be given as a string without dots (e.g. "37" for 3.7.0).
+    """),
+)  # type: Callable[..., Option]
+
+
+implementation = partial(
+    Option,
+    '--implementation',
+    dest='implementation',
+    metavar='implementation',
+    default=None,
+    help=("Only use wheels compatible with Python "
+          "implementation <implementation>, e.g. 'pp', 'jy', 'cp', "
+          " or 'ip'. If not specified, then the current "
+          "interpreter implementation is used.  Use 'py' to force "
+          "implementation-agnostic wheels."),
+)  # type: Callable[..., Option]
+
+
+abi = partial(
+    Option,
+    '--abi',
+    dest='abi',
+    metavar='abi',
+    default=None,
+    help=("Only use wheels compatible with Python "
+          "abi <abi>, e.g. 'pypy_41'.  If not specified, then the "
+          "current interpreter abi tag is used.  Generally "
+          "you will need to specify --implementation, "
+          "--platform, and --python-version when using "
+          "this option."),
+)  # type: Callable[..., Option]
+
+
+def add_target_python_options(cmd_opts):
+    # type: (OptionGroup) -> None
+    cmd_opts.add_option(platform())
+    cmd_opts.add_option(python_version())
+    cmd_opts.add_option(implementation())
+    cmd_opts.add_option(abi())
+
+
+def make_target_python(options):
+    # type: (Values) -> TargetPython
+    target_python = TargetPython(
+        platform=options.platform,
+        py_version_info=options.python_version,
+        abi=options.abi,
+        implementation=options.implementation,
+    )
+
+    return target_python
+
+
+def prefer_binary():
+    # type: () -> Option
+    return Option(
+        "--prefer-binary",
+        dest="prefer_binary",
+        action="store_true",
+        default=False,
+        help="Prefer older binary packages over newer source packages."
+    )
+
+
+cache_dir = partial(
+    PipOption,
+    "--cache-dir",
+    dest="cache_dir",
+    default=USER_CACHE_DIR,
+    metavar="dir",
+    type='path',
+    help="Store the cache data in <dir>."
+)  # type: Callable[..., Option]
+
+
+def _handle_no_cache_dir(option, opt, value, parser):
+    # type: (Option, str, str, OptionParser) -> None
+    """
+    Process a value provided for the --no-cache-dir option.
+
+    This is an optparse.Option callback for the --no-cache-dir option.
+    """
+    # The value argument will be None if --no-cache-dir is passed via the
+    # command-line, since the option doesn't accept arguments.  However,
+    # the value can be non-None if the option is triggered e.g. by an
+    # environment variable, like PIP_NO_CACHE_DIR=true.
+    if value is not None:
+        # Then parse the string value to get argument error-checking.
+        try:
+            strtobool(value)
+        except ValueError as exc:
+            raise_option_error(parser, option=option, msg=str(exc))
+
+    # Originally, setting PIP_NO_CACHE_DIR to a value that strtobool()
+    # converted to 0 (like "false" or "no") caused cache_dir to be disabled
+    # rather than enabled (logic would say the latter).  Thus, we disable
+    # the cache directory not just on values that parse to True, but (for
+    # backwards compatibility reasons) also on values that parse to False.
+    # In other words, always set it to False if the option is provided in
+    # some (valid) form.
+    parser.values.cache_dir = False
+
+
+no_cache = partial(
+    Option,
+    "--no-cache-dir",
+    dest="cache_dir",
+    action="callback",
+    callback=_handle_no_cache_dir,
+    help="Disable the cache.",
+)  # type: Callable[..., Option]
+
+no_deps = partial(
+    Option,
+    '--no-deps', '--no-dependencies',
+    dest='ignore_dependencies',
+    action='store_true',
+    default=False,
+    help="Don't install package dependencies.",
+)  # type: Callable[..., Option]
+
+
+def _handle_build_dir(option, opt, value, parser):
+    # type: (Option, str, str, OptionParser) -> None
+    if value:
+        value = os.path.abspath(value)
+    setattr(parser.values, option.dest, value)
+
+
+build_dir = partial(
+    PipOption,
+    '-b', '--build', '--build-dir', '--build-directory',
+    dest='build_dir',
+    type='path',
+    metavar='dir',
+    action='callback',
+    callback=_handle_build_dir,
+    help='Directory to unpack packages into and build in. Note that '
+         'an initial build still takes place in a temporary directory. '
+         'The location of temporary directories can be controlled by setting '
+         'the TMPDIR environment variable (TEMP on Windows) appropriately. '
+         'When passed, build directories are not cleaned in case of failures.'
+)  # type: Callable[..., Option]
+
+ignore_requires_python = partial(
+    Option,
+    '--ignore-requires-python',
+    dest='ignore_requires_python',
+    action='store_true',
+    help='Ignore the Requires-Python information.'
+)  # type: Callable[..., Option]
+
+no_build_isolation = partial(
+    Option,
+    '--no-build-isolation',
+    dest='build_isolation',
+    action='store_false',
+    default=True,
+    help='Disable isolation when building a modern source distribution. '
+         'Build dependencies specified by PEP 518 must be already installed '
+         'if this option is used.'
+)  # type: Callable[..., Option]
+
+
+def _handle_no_use_pep517(option, opt, value, parser):
+    # type: (Option, str, str, OptionParser) -> None
+    """
+    Process a value provided for the --no-use-pep517 option.
+
+    This is an optparse.Option callback for the no_use_pep517 option.
+    """
+    # Since --no-use-pep517 doesn't accept arguments, the value argument
+    # will be None if --no-use-pep517 is passed via the command-line.
+    # However, the value can be non-None if the option is triggered e.g.
+    # by an environment variable, for example "PIP_NO_USE_PEP517=true".
+    if value is not None:
+        msg = """A value was passed for --no-use-pep517,
+        probably using either the PIP_NO_USE_PEP517 environment variable
+        or the "no-use-pep517" config file option. Use an appropriate value
+        of the PIP_USE_PEP517 environment variable or the "use-pep517"
+        config file option instead.
+        """
+        raise_option_error(parser, option=option, msg=msg)
+
+    # Otherwise, --no-use-pep517 was passed via the command-line.
+    parser.values.use_pep517 = False
+
+
+use_pep517 = partial(
+    Option,
+    '--use-pep517',
+    dest='use_pep517',
+    action='store_true',
+    default=None,
+    help='Use PEP 517 for building source distributions '
+         '(use --no-use-pep517 to force legacy behaviour).'
+)  # type: Any
+
+no_use_pep517 = partial(
+    Option,
+    '--no-use-pep517',
+    dest='use_pep517',
+    action='callback',
+    callback=_handle_no_use_pep517,
+    default=None,
+    help=SUPPRESS_HELP
+)  # type: Any
+
+install_options = partial(
+    Option,
+    '--install-option',
+    dest='install_options',
+    action='append',
+    metavar='options',
+    help="Extra arguments to be supplied to the setup.py install "
+         "command (use like --install-option=\"--install-scripts=/usr/local/"
+         "bin\"). Use multiple --install-option options to pass multiple "
+         "options to setup.py install. If you are using an option with a "
+         "directory path, be sure to use absolute path.",
+)  # type: Callable[..., Option]
+
+global_options = partial(
+    Option,
+    '--global-option',
+    dest='global_options',
+    action='append',
+    metavar='options',
+    help="Extra global options to be supplied to the setup.py "
+         "call before the install command.",
+)  # type: Callable[..., Option]
+
+no_clean = partial(
+    Option,
+    '--no-clean',
+    action='store_true',
+    default=False,
+    help="Don't clean up build directories."
+)  # type: Callable[..., Option]
+
+pre = partial(
+    Option,
+    '--pre',
+    action='store_true',
+    default=False,
+    help="Include pre-release and development versions. By default, "
+         "pip only finds stable versions.",
+)  # type: Callable[..., Option]
+
+disable_pip_version_check = partial(
+    Option,
+    "--disable-pip-version-check",
+    dest="disable_pip_version_check",
+    action="store_true",
+    default=False,
+    help="Don't periodically check PyPI to determine whether a new version "
+         "of pip is available for download. Implied with --no-index.",
+)  # type: Callable[..., Option]
+
+
+# Deprecated, Remove later
+always_unzip = partial(
+    Option,
+    '-Z', '--always-unzip',
+    dest='always_unzip',
+    action='store_true',
+    help=SUPPRESS_HELP,
+)  # type: Callable[..., Option]
+
+
+def _handle_merge_hash(option, opt_str, value, parser):
+    # type: (Option, str, str, OptionParser) -> None
+    """Given a value spelled "algo:digest", append the digest to a list
+    pointed to in a dict by the algo name."""
+    if not parser.values.hashes:
+        parser.values.hashes = {}
+    try:
+        algo, digest = value.split(':', 1)
+    except ValueError:
+        parser.error('Arguments to %s must be a hash name '
+                     'followed by a value, like --hash=sha256:abcde...' %
+                     opt_str)
+    if algo not in STRONG_HASHES:
+        parser.error('Allowed hash algorithms for %s are %s.' %
+                     (opt_str, ', '.join(STRONG_HASHES)))
+    parser.values.hashes.setdefault(algo, []).append(digest)
+
+
+hash = partial(
+    Option,
+    '--hash',
+    # Hash values eventually end up in InstallRequirement.hashes due to
+    # __dict__ copying in process_line().
+    dest='hashes',
+    action='callback',
+    callback=_handle_merge_hash,
+    type='string',
+    help="Verify that the package's archive matches this "
+         'hash before installing. Example: --hash=sha256:abcdef...',
+)  # type: Callable[..., Option]
+
+
+require_hashes = partial(
+    Option,
+    '--require-hashes',
+    dest='require_hashes',
+    action='store_true',
+    default=False,
+    help='Require a hash to check each requirement against, for '
+         'repeatable installs. This option is implied when any package in a '
+         'requirements file has a --hash option.',
+)  # type: Callable[..., Option]
+
+
+list_path = partial(
+    PipOption,
+    '--path',
+    dest='path',
+    type='path',
+    action='append',
+    help='Restrict to the specified installation path for listing '
+         'packages (can be used multiple times).'
+)  # type: Callable[..., Option]
+
+
+def check_list_path_option(options):
+    # type: (Values) -> None
+    if options.path and (options.user or options.local):
+        raise CommandError(
+            "Cannot combine '--path' with '--user' or '--local'"
+        )
+
+
+no_python_version_warning = partial(
+    Option,
+    '--no-python-version-warning',
+    dest='no_python_version_warning',
+    action='store_true',
+    default=False,
+    help='Silence deprecation warnings for upcoming unsupported Pythons.',
+)  # type: Callable[..., Option]
+
+
+##########
+# groups #
+##########
+
+general_group = {
+    'name': 'General Options',
+    'options': [
+        help_,
+        isolated_mode,
+        require_virtualenv,
+        verbose,
+        version,
+        quiet,
+        log,
+        no_input,
+        proxy,
+        retries,
+        timeout,
+        skip_requirements_regex,
+        exists_action,
+        trusted_host,
+        cert,
+        client_cert,
+        cache_dir,
+        no_cache,
+        disable_pip_version_check,
+        no_color,
+        no_python_version_warning,
+    ]
+}  # type: Dict[str, Any]
+
+index_group = {
+    'name': 'Package Index Options',
+    'options': [
+        index_url,
+        extra_index_url,
+        no_index,
+        find_links,
+    ]
+}  # type: Dict[str, Any]

env/lib/python3.5/site-packages/pip/_internal/cli/command_context.py

+from contextlib import contextmanager
+
+from pip._vendor.contextlib2 import ExitStack
+
+from pip._internal.utils.typing import MYPY_CHECK_RUNNING
+
+if MYPY_CHECK_RUNNING:
+    from typing import Iterator, ContextManager, TypeVar
+
+    _T = TypeVar('_T', covariant=True)
+
+
+class CommandContextMixIn(object):
+    def __init__(self):
+        # type: () -> None
+        super(CommandContextMixIn, self).__init__()
+        self._in_main_context = False
+        self._main_context = ExitStack()
+
+    @contextmanager
+    def main_context(self):
+        # type: () -> Iterator[None]
+        assert not self._in_main_context
+
+        self._in_main_context = True
+        try:
+            with self._main_context:
+                yield
+        finally:
+            self._in_main_context = False
+
+    def enter_context(self, context_provider):
+        # type: (ContextManager[_T]) -> _T
+        assert self._in_main_context
+
+        return self._main_context.enter_context(context_provider)

env/lib/python3.5/site-packages/pip/_internal/cli/main.py

+"""Primary application entrypoint.
+"""
+from __future__ import absolute_import
+
+import locale
+import logging
+import os
+import sys
+
+from pip._internal.cli.autocompletion import autocomplete
+from pip._internal.cli.main_parser import parse_command
+from pip._internal.commands import create_command
+from pip._internal.exceptions import PipError
+from pip._internal.utils import deprecation
+from pip._internal.utils.typing import MYPY_CHECK_RUNNING
+
+if MYPY_CHECK_RUNNING:
+    from typing import List, Optional
+
+logger = logging.getLogger(__name__)
+
+
+# Do not import and use main() directly! Using it directly is actively
+# discouraged by pip's maintainers. The name, location and behavior of
+# this function is subject to change, so calling it directly is not
+# portable across different pip versions.
+
+# In addition, running pip in-process is unsupported and unsafe. This is
+# elaborated in detail at
+# https://pip.pypa.io/en/stable/user_guide/#using-pip-from-your-program.
+# That document also provides suggestions that should work for nearly
+# all users that are considering importing and using main() directly.
+
+# However, we know that certain users will still want to invoke pip
+# in-process. If you understand and accept the implications of using pip
+# in an unsupported manner, the best approach is to use runpy to avoid
+# depending on the exact location of this entry point.
+
+# The following example shows how to use runpy to invoke pip in that
+# case:
+#
+#     sys.argv = ["pip", your, args, here]
+#     runpy.run_module("pip", run_name="__main__")
+#
+# Note that this will exit the process after running, unlike a direct
+# call to main. As it is not safe to do any processing after calling
+# main, this should not be an issue in practice.
+
+def main(args=None):
+    # type: (Optional[List[str]]) -> int
+    if args is None:
+        args = sys.argv[1:]
+
+    # Configure our deprecation warnings to be sent through loggers
+    deprecation.install_warning_logger()
+
+    autocomplete()
+
+    try:
+        cmd_name, cmd_args = parse_command(args)
+    except PipError as exc:
+        sys.stderr.write("ERROR: %s" % exc)
+        sys.stderr.write(os.linesep)
+        sys.exit(1)
+
+    # Needed for locale.getpreferredencoding(False) to work
+    # in pip._internal.utils.encoding.auto_decode
+    try:
+        locale.setlocale(locale.LC_ALL, '')
+    except locale.Error as e:
+        # setlocale can apparently crash if locale are uninitialized
+        logger.debug("Ignoring error %s when setting locale", e)
+    command = create_command(cmd_name, isolated=("--isolated" in cmd_args))
+
+    return command.main(cmd_args)

env/lib/python3.5/site-packages/pip/_internal/cli/main_parser.py

+"""A single place for constructing and exposing the main parser
+"""
+
+import os
+import sys
+
+from pip._internal.cli import cmdoptions
+from pip._internal.cli.parser import (
+    ConfigOptionParser,
+    UpdatingDefaultsHelpFormatter,
+)
+from pip._internal.commands import commands_dict, get_similar_commands
+from pip._internal.exceptions import CommandError
+from pip._internal.utils.misc import get_pip_version, get_prog
+from pip._internal.utils.typing import MYPY_CHECK_RUNNING
+
+if MYPY_CHECK_RUNNING:
+    from typing import Tuple, List
+
+
+__all__ = ["create_main_parser", "parse_command"]
+
+
+def create_main_parser():
+    # type: () -> ConfigOptionParser
+    """Creates and returns the main parser for pip's CLI
+    """
+
+    parser_kw = {
+        'usage': '\n%prog <command> [options]',
+        'add_help_option': False,
+        'formatter': UpdatingDefaultsHelpFormatter(),
+        'name': 'global',
+        'prog': get_prog(),
+    }
+
+    parser = ConfigOptionParser(**parser_kw)
+    parser.disable_interspersed_args()
+
+    parser.version = get_pip_version()
+
+    # add the general options
+    gen_opts = cmdoptions.make_option_group(cmdoptions.general_group, parser)
+    parser.add_option_group(gen_opts)
+
+    # so the help formatter knows
+    parser.main = True  # type: ignore
+
+    # create command listing for description
+    description = [''] + [
+        '%-27s %s' % (name, command_info.summary)
+        for name, command_info in commands_dict.items()
+    ]
+    parser.description = '\n'.join(description)
+
+    return parser
+
+
+def parse_command(args):
+    # type: (List[str]) -> Tuple[str, List[str]]
+    parser = create_main_parser()
+
+    # Note: parser calls disable_interspersed_args(), so the result of this
+    # call is to split the initial args into the general options before the
+    # subcommand and everything else.
+    # For example:
+    #  args: ['--timeout=5', 'install', '--user', 'INITools']
+    #  general_options: ['--timeout==5']
+    #  args_else: ['install', '--user', 'INITools']
+    general_options, args_else = parser.parse_args(args)
+
+    # --version
+    if general_options.version:
+        sys.stdout.write(parser.version)  # type: ignore
+        sys.stdout.write(os.linesep)
+        sys.exit()
+
+    # pip || pip help -> print_help()
+    if not args_else or (args_else[0] == 'help' and len(args_else) == 1):
+        parser.print_help()
+        sys.exit()
+
+    # the subcommand name
+    cmd_name = args_else[0]
+
+    if cmd_name not in commands_dict:
+        guess = get_similar_commands(cmd_name)
+
+        msg = ['unknown command "%s"' % cmd_name]
+        if guess:
+            msg.append('maybe you meant "%s"' % guess)
+
+        raise CommandError(' - '.join(msg))
+
+    # all the args without the subcommand
+    cmd_args = args[:]
+    cmd_args.remove(cmd_name)
+
+    return cmd_name, cmd_args

env/lib/python3.5/site-packages/pip/_internal/cli/parser.py

+"""Base option parser setup"""
+
+# The following comment should be removed at some point in the future.
+# mypy: disallow-untyped-defs=False
+
+from __future__ import absolute_import
+
+import logging
+import optparse
+import sys
+import textwrap
+from distutils.util import strtobool
+
+from pip._vendor.six import string_types
+
+from pip._internal.cli.status_codes import UNKNOWN_ERROR
+from pip._internal.configuration import Configuration, ConfigurationError
+from pip._internal.utils.compat import get_terminal_size
+
+logger = logging.getLogger(__name__)
+
+
+class PrettyHelpFormatter(optparse.IndentedHelpFormatter):
+    """A prettier/less verbose help formatter for optparse."""
+
+    def __init__(self, *args, **kwargs):
+        # help position must be aligned with __init__.parseopts.description
+        kwargs['max_help_position'] = 30
+        kwargs['indent_increment'] = 1
+        kwargs['width'] = get_terminal_size()[0] - 2
+        optparse.IndentedHelpFormatter.__init__(self, *args, **kwargs)
+
+    def format_option_strings(self, option):
+        return self._format_option_strings(option, ' <%s>', ', ')
+
+    def _format_option_strings(self, option, mvarfmt=' <%s>', optsep=', '):
+        """
+        Return a comma-separated list of option strings and metavars.
+
+        :param option:  tuple of (short opt, long opt), e.g: ('-f', '--format')
+        :param mvarfmt: metavar format string - evaluated as mvarfmt % metavar
+        :param optsep:  separator
+        """
+        opts = []
+
+        if option._short_opts:
+            opts.append(option._short_opts[0])
+        if option._long_opts:
+            opts.append(option._long_opts[0])
+        if len(opts) > 1:
+            opts.insert(1, optsep)
+
+        if option.takes_value():
+            metavar = option.metavar or option.dest.lower()
+            opts.append(mvarfmt % metavar.lower())
+
+        return ''.join(opts)
+
+    def format_heading(self, heading):
+        if heading == 'Options':
+            return ''
+        return heading + ':\n'
+
+    def format_usage(self, usage):
+        """
+        Ensure there is only one newline between usage and the first heading
+        if there is no description.
+        """
+        msg = '\nUsage: %s\n' % self.indent_lines(textwrap.dedent(usage), "  ")
+        return msg
+
+    def format_description(self, description):
+        # leave full control over description to us
+        if description:
+            if hasattr(self.parser, 'main'):
+                label = 'Commands'
+            else:
+                label = 'Description'
+            # some doc strings have initial newlines, some don't
+            description = description.lstrip('\n')
+            # some doc strings have final newlines and spaces, some don't
+            description = description.rstrip()
+            # dedent, then reindent
+            description = self.indent_lines(textwrap.dedent(description), "  ")
+            description = '%s:\n%s\n' % (label, description)
+            return description
+        else:
+            return ''
+
+    def format_epilog(self, epilog):
+        # leave full control over epilog to us
+        if epilog:
+            return epilog
+        else:
+            return ''
+
+    def indent_lines(self, text, indent):
+        new_lines = [indent + line for line in text.split('\n')]
+        return "\n".join(new_lines)
+
+
+class UpdatingDefaultsHelpFormatter(PrettyHelpFormatter):
+    """Custom help formatter for use in ConfigOptionParser.
+
+    This is updates the defaults before expanding them, allowing
+    them to show up correctly in the help listing.
+    """
+
+    def expand_default(self, option):
+        if self.parser is not None:
+            self.parser._update_defaults(self.parser.defaults)
+        return optparse.IndentedHelpFormatter.expand_default(self, option)
+
+
+class CustomOptionParser(optparse.OptionParser):
+
+    def insert_option_group(self, idx, *args, **kwargs):
+        """Insert an OptionGroup at a given position."""
+        group = self.add_option_group(*args, **kwargs)
+
+        self.option_groups.pop()
+        self.option_groups.insert(idx, group)
+
+        return group
+
+    @property
+    def option_list_all(self):
+        """Get a list of all options, including those in option groups."""
+        res = self.option_list[:]
+        for i in self.option_groups:
+            res.extend(i.option_list)
+
+        return res
+
+
+class ConfigOptionParser(CustomOptionParser):
+    """Custom option parser which updates its defaults by checking the
+    configuration files and environmental variables"""
+
+    def __init__(self, *args, **kwargs):
+        self.name = kwargs.pop('name')
+
+        isolated = kwargs.pop("isolated", False)
+        self.config = Configuration(isolated)
+
+        assert self.name
+        optparse.OptionParser.__init__(self, *args, **kwargs)
+
+    def check_default(self, option, key, val):
+        try:
+            return option.check_value(key, val)
+        except optparse.OptionValueError as exc:
+            print("An error occurred during configuration: %s" % exc)
+            sys.exit(3)
+
+    def _get_ordered_configuration_items(self):
+        # Configuration gives keys in an unordered manner. Order them.
+        override_order = ["global", self.name, ":env:"]
+
+        # Pool the options into different groups
+        section_items = {name: [] for name in override_order}
+        for section_key, val in self.config.items():
+            # ignore empty values
+            if not val:
+                logger.debug(
+                    "Ignoring configuration key '%s' as it's value is empty.",
+                    section_key
+                )
+                continue
+
+            section, key = section_key.split(".", 1)
+            if section in override_order:
+                section_items[section].append((key, val))
+
+        # Yield each group in their override order
+        for section in override_order:
+            for key, val in section_items[section]:
+                yield key, val
+
+    def _update_defaults(self, defaults):
+        """Updates the given defaults with values from the config files and
+        the environ. Does a little special handling for certain types of
+        options (lists)."""
+
+        # Accumulate complex default state.
+        self.values = optparse.Values(self.defaults)
+        late_eval = set()
+        # Then set the options with those values
+        for key, val in self._get_ordered_configuration_items():
+            # '--' because configuration supports only long names
+            option = self.get_option('--' + key)
+
+            # Ignore options not present in this parser. E.g. non-globals put
+            # in [global] by users that want them to apply to all applicable
+            # commands.
+            if option is None:
+                continue
+
+            if option.action in ('store_true', 'store_false', 'count'):
+                try:
+                    val = strtobool(val)
+                except ValueError:
+                    error_msg = invalid_config_error_message(
+                        option.action, key, val
+                    )
+                    self.error(error_msg)
+
+            elif option.action == 'append':
+                val = val.split()
+                val = [self.check_default(option, key, v) for v in val]
+            elif option.action == 'callback':
+                late_eval.add(option.dest)
+                opt_str = option.get_opt_string()
+                val = option.convert_value(opt_str, val)
+                # From take_action
+                args = option.callback_args or ()
+                kwargs = option.callback_kwargs or {}
+                option.callback(option, opt_str, val, self, *args, **kwargs)
+            else:
+                val = self.check_default(option, key, val)
+
+            defaults[option.dest] = val
+
+        for key in late_eval:
+            defaults[key] = getattr(self.values, key)
+        self.values = None
+        return defaults
+
+    def get_default_values(self):
+        """Overriding to make updating the defaults after instantiation of
+        the option parser possible, _update_defaults() does the dirty work."""
+        if not self.process_default_values:
+            # Old, pre-Optik 1.5 behaviour.
+            return optparse.Values(self.defaults)
+
+        # Load the configuration, or error out in case of an error
+        try:
+            self.config.load()
+        except ConfigurationError as err:
+            self.exit(UNKNOWN_ERROR, str(err))
+
+        defaults = self._update_defaults(self.defaults.copy())  # ours
+        for option in self._get_all_options():
+            default = defaults.get(option.dest)
+            if isinstance(default, string_types):
+                opt_str = option.get_opt_string()
+                defaults[option.dest] = option.check_value(opt_str, default)
+        return optparse.Values(defaults)
+
+    def error(self, msg):
+        self.print_usage(sys.stderr)
+        self.exit(UNKNOWN_ERROR, "%s\n" % msg)
+
+
+def invalid_config_error_message(action, key, val):
+    """Returns a better error message when invalid configuration option
+    is provided."""
+    if action in ('store_true', 'store_false'):
+        return ("{0} is not a valid value for {1} option, "
+                "please specify a boolean value like yes/no, "
+                "true/false or 1/0 instead.").format(val, key)
+
+    return ("{0} is not a valid value for {1} option, "
+            "please specify a numerical value like 1/0 "
+            "instead.").format(val, key)

env/lib/python3.5/site-packages/pip/_internal/cli/req_command.py

+"""Contains the Command base classes that depend on PipSession.
+
+The classes in this module are in a separate module so the commands not
+needing download / PackageFinder capability don't unnecessarily import the
+PackageFinder machinery and all its vendored dependencies, etc.
+"""
+
+import logging
+import os
+from functools import partial
+
+from pip._internal.cli.base_command import Command
+from pip._internal.cli.command_context import CommandContextMixIn
+from pip._internal.exceptions import CommandError
+from pip._internal.index.package_finder import PackageFinder
+from pip._internal.legacy_resolve import Resolver
+from pip._internal.models.selection_prefs import SelectionPreferences
+from pip._internal.network.download import Downloader
+from pip._internal.network.session import PipSession
+from pip._internal.operations.prepare import RequirementPreparer
+from pip._internal.req.constructors import (
+    install_req_from_editable,
+    install_req_from_line,
+    install_req_from_req_string,
+)
+from pip._internal.req.req_file import parse_requirements
+from pip._internal.self_outdated_check import (
+    make_link_collector,
+    pip_self_version_check,
+)
+from pip._internal.utils.typing import MYPY_CHECK_RUNNING
+
+if MYPY_CHECK_RUNNING:
+    from optparse import Values
+    from typing import List, Optional, Tuple
+    from pip._internal.cache import WheelCache
+    from pip._internal.models.target_python import TargetPython
+    from pip._internal.req.req_set import RequirementSet
+    from pip._internal.req.req_tracker import RequirementTracker
+    from pip._internal.utils.temp_dir import TempDirectory
+
+logger = logging.getLogger(__name__)
+
+
+class SessionCommandMixin(CommandContextMixIn):
+
+    """
+    A class mixin for command classes needing _build_session().
+    """
+    def __init__(self):
+        # type: () -> None
+        super(SessionCommandMixin, self).__init__()
+        self._session = None  # Optional[PipSession]
+
+    @classmethod
+    def _get_index_urls(cls, options):
+        # type: (Values) -> Optional[List[str]]
+        """Return a list of index urls from user-provided options."""
+        index_urls = []
+        if not getattr(options, "no_index", False):
+            url = getattr(options, "index_url", None)
+            if url:
+                index_urls.append(url)
+        urls = getattr(options, "extra_index_urls", None)
+        if urls:
+            index_urls.extend(urls)
+        # Return None rather than an empty list
+        return index_urls or None
+
+    def get_default_session(self, options):
+        # type: (Values) -> PipSession
+        """Get a default-managed session."""
+        if self._session is None:
+            self._session = self.enter_context(self._build_session(options))
+            # there's no type annotation on requests.Session, so it's
+            # automatically ContextManager[Any] and self._session becomes Any,
+            # then https://github.com/python/mypy/issues/7696 kicks in
+            assert self._session is not None
+        return self._session
+
+    def _build_session(self, options, retries=None, timeout=None):
+        # type: (Values, Optional[int], Optional[int]) -> PipSession
+        assert not options.cache_dir or os.path.isabs(options.cache_dir)
+        session = PipSession(
+            cache=(
+                os.path.join(options.cache_dir, "http")
+                if options.cache_dir else None
+            ),
+            retries=retries if retries is not None else options.retries,
+            trusted_hosts=options.trusted_hosts,
+            index_urls=self._get_index_urls(options),
+        )
+
+        # Handle custom ca-bundles from the user
+        if options.cert:
+            session.verify = options.cert
+
+        # Handle SSL client certificate
+        if options.client_cert:
+            session.cert = options.client_cert
+
+        # Handle timeouts
+        if options.timeout or timeout:
+            session.timeout = (
+                timeout if timeout is not None else options.timeout
+            )
+
+        # Handle configured proxies
+        if options.proxy:
+            session.proxies = {
+                "http": options.proxy,
+                "https": options.proxy,
+            }
+
+        # Determine if we can prompt the user for authentication or not
+        session.auth.prompting = not options.no_input
+
+        return session
+
+
+class IndexGroupCommand(Command, SessionCommandMixin):
+
+    """
+    Abstract base class for commands with the index_group options.
+
+    This also corresponds to the commands that permit the pip version check.
+    """
+
+    def handle_pip_version_check(self, options):
+        # type: (Values) -> None
+        """
+        Do the pip version check if not disabled.
+
+        This overrides the default behavior of not doing the check.
+        """
+        # Make sure the index_group options are present.
+        assert hasattr(options, 'no_index')
+
+        if options.disable_pip_version_check or options.no_index:
+            return
+
+        # Otherwise, check if we're using the latest version of pip available.
+        session = self._build_session(
+            options,
+            retries=0,
+            timeout=min(5, options.timeout)
+        )
+        with session:
+            pip_self_version_check(session, options)
+
+
+class RequirementCommand(IndexGroupCommand):
+
+    @staticmethod
+    def make_requirement_preparer(
+        temp_build_dir,           # type: TempDirectory
+        options,                  # type: Values
+        req_tracker,              # type: RequirementTracker
+        session,                  # type: PipSession
+        finder,                   # type: PackageFinder
+        use_user_site,            # type: bool
+        download_dir=None,        # type: str
+        wheel_download_dir=None,  # type: str
+    ):
+        # type: (...) -> RequirementPreparer
+        """
+        Create a RequirementPreparer instance for the given parameters.
+        """
+        downloader = Downloader(session, progress_bar=options.progress_bar)
+
+        temp_build_dir_path = temp_build_dir.path
+        assert temp_build_dir_path is not None
+
+        return RequirementPreparer(
+            build_dir=temp_build_dir_path,
+            src_dir=options.src_dir,
+            download_dir=download_dir,
+            wheel_download_dir=wheel_download_dir,
+            build_isolation=options.build_isolation,
+            req_tracker=req_tracker,
+            downloader=downloader,
+            finder=finder,
+            require_hashes=options.require_hashes,
+            use_user_site=use_user_site,
+        )
+
+    @staticmethod
+    def make_resolver(
+        preparer,                            # type: RequirementPreparer
+        finder,                              # type: PackageFinder
+        options,                             # type: Values
+        wheel_cache=None,                    # type: Optional[WheelCache]
+        use_user_site=False,                 # type: bool
+        ignore_installed=True,               # type: bool
+        ignore_requires_python=False,        # type: bool
+        force_reinstall=False,               # type: bool
+        upgrade_strategy="to-satisfy-only",  # type: str
+        use_pep517=None,                     # type: Optional[bool]
+        py_version_info=None            # type: Optional[Tuple[int, ...]]
+    ):
+        # type: (...) -> Resolver
+        """
+        Create a Resolver instance for the given parameters.
+        """
+        make_install_req = partial(
+            install_req_from_req_string,
+            isolated=options.isolated_mode,
+            wheel_cache=wheel_cache,
+            use_pep517=use_pep517,
+        )
+        return Resolver(
+            preparer=preparer,
+            finder=finder,
+            make_install_req=make_install_req,
+            use_user_site=use_user_site,
+            ignore_dependencies=options.ignore_dependencies,
+            ignore_installed=ignore_installed,
+            ignore_requires_python=ignore_requires_python,
+            force_reinstall=force_reinstall,
+            upgrade_strategy=upgrade_strategy,
+            py_version_info=py_version_info,
+        )
+
+    def populate_requirement_set(
+        self,
+        requirement_set,  # type: RequirementSet
+        args,             # type: List[str]
+        options,          # type: Values
+        finder,           # type: PackageFinder
+        session,          # type: PipSession
+        wheel_cache,      # type: Optional[WheelCache]
+    ):
+        # type: (...) -> None
+        """
+        Marshal cmd line args into a requirement set.
+        """
+        for filename in options.constraints:
+            for req_to_add in parse_requirements(
+                    filename,
+                    constraint=True, finder=finder, options=options,
+                    session=session, wheel_cache=wheel_cache):
+                req_to_add.is_direct = True
+                requirement_set.add_requirement(req_to_add)
+
+        for req in args:
+            req_to_add = install_req_from_line(
+                req, None, isolated=options.isolated_mode,
+                use_pep517=options.use_pep517,
+                wheel_cache=wheel_cache
+            )
+            req_to_add.is_direct = True
+            requirement_set.add_requirement(req_to_add)
+
+        for req in options.editables:
+            req_to_add = install_req_from_editable(
+                req,
+                isolated=options.isolated_mode,
+                use_pep517=options.use_pep517,
+                wheel_cache=wheel_cache
+            )
+            req_to_add.is_direct = True
+            requirement_set.add_requirement(req_to_add)
+
+        # NOTE: options.require_hashes may be set if --require-hashes is True
+        for filename in options.requirements:
+            for req_to_add in parse_requirements(
+                    filename,
+                    finder=finder, options=options, session=session,
+                    wheel_cache=wheel_cache,
+                    use_pep517=options.use_pep517):
+                req_to_add.is_direct = True
+                requirement_set.add_requirement(req_to_add)
+
+        # If any requirement has hash options, enable hash checking.
+        requirements = (
+            requirement_set.unnamed_requirements +
+            list(requirement_set.requirements.values())
+        )
+        if any(req.has_hash_options for req in requirements):
+            options.require_hashes = True
+
+        if not (args or options.editables or options.requirements):
+            opts = {'name': self.name}
+            if options.find_links:
+                raise CommandError(
+                    'You must give at least one requirement to %(name)s '
+                    '(maybe you meant "pip %(name)s %(links)s"?)' %
+                    dict(opts, links=' '.join(options.find_links)))
+            else:
+                raise CommandError(
+                    'You must give at least one requirement to %(name)s '
+                    '(see "pip help %(name)s")' % opts)
+
+    @staticmethod
+    def trace_basic_info(finder):
+        # type: (PackageFinder) -> None
+        """
+        Trace basic information about the provided objects.
+        """
+        # Display where finder is looking for packages
+        search_scope = finder.search_scope
+        locations = search_scope.get_formatted_locations()
+        if locations:
+            logger.info(locations)
+
+    def _build_package_finder(
+        self,
+        options,               # type: Values
+        session,               # type: PipSession
+        target_python=None,    # type: Optional[TargetPython]
+        ignore_requires_python=None,  # type: Optional[bool]
+    ):
+        # type: (...) -> PackageFinder
+        """
+        Create a package finder appropriate to this requirement command.
+
+        :param ignore_requires_python: Whether to ignore incompatible
+            "Requires-Python" values in links. Defaults to False.
+        """
+        link_collector = make_link_collector(session, options=options)
+        selection_prefs = SelectionPreferences(
+            allow_yanked=True,
+            format_control=options.format_control,
+            allow_all_prereleases=options.pre,
+            prefer_binary=options.prefer_binary,
+            ignore_requires_python=ignore_requires_python,
+        )
+
+        return PackageFinder.create(
+            link_collector=link_collector,
+            selection_prefs=selection_prefs,
+            target_python=target_python,
+        )