virtualEnvironment/lib/python2.7/site-packages/pip/req/req_set.py
def prepare_files(self, finder):
        """
        Prepare process. Create temp directories, download and/or unpack files.
        """
        from pip.index import Link

        unnamed = list(self.unnamed_requirements)
        reqs = list(self.requirements.values())
        while reqs or unnamed:
            if unnamed:
                req_to_install = unnamed.pop(0)
            else:
                req_to_install = reqs.pop(0)
            install = True
            best_installed = False
            not_found = None

            # ############################################# #
            # # Search for archive to fulfill requirement # #
            # ############################################# #

            if not self.ignore_installed and not req_to_install.editable:
                req_to_install.check_if_exists()
                if req_to_install.satisfied_by:
                    if self.upgrade:
                        if not self.force_reinstall and not req_to_install.url:
                            try:
                                url = finder.find_requirement(
                                    req_to_install, self.upgrade)
                            except BestVersionAlreadyInstalled:
                                best_installed = True
                                install = False
                            except DistributionNotFound as exc:
                                not_found = exc
                            else:
                                # Avoid the need to call find_requirement again
                                req_to_install.url = url.url

                        if not best_installed:
                            # don't uninstall conflict if user install and
                            # conflict is not user install
                            if not (self.use_user_site
                                    and not dist_in_usersite(
                                        req_to_install.satisfied_by
                                    )):
                                req_to_install.conflicts_with = \
                                    req_to_install.satisfied_by
                            req_to_install.satisfied_by = None
                    else:
                        install = False
                if req_to_install.satisfied_by:
                    if best_installed:
                        logger.info(
                            'Requirement already up-to-date: %s',
                            req_to_install,
                        )
                    else:
                        logger.info(
                            'Requirement already satisfied (use --upgrade to '
                            'upgrade): %s',
                            req_to_install,
                        )
            if req_to_install.editable:
                logger.info('Obtaining %s', req_to_install)
            elif install:
                if (req_to_install.url
                        and req_to_install.url.lower().startswith('file:')):
                    path = url_to_path(req_to_install.url)
                    logger.info('Processing %s', display_path(path))
                else:
                    logger.info('Collecting %s', req_to_install)

            with indent_log():
                # ################################ #
                # # vcs update or unpack archive # #
                # ################################ #

                is_wheel = False
                if req_to_install.editable:
                    if req_to_install.source_dir is None:
                        location = req_to_install.build_location(self.src_dir)
                        req_to_install.source_dir = location
                    else:
                        location = req_to_install.source_dir
                    if not os.path.exists(self.build_dir):
                        _make_build_dir(self.build_dir)
                    req_to_install.update_editable(not self.is_download)
                    if self.is_download:
                        req_to_install.run_egg_info()
                        req_to_install.archive(self.download_dir)
                    else:
                        req_to_install.run_egg_info()
                elif install:
                    # @@ if filesystem packages are not marked
                    # editable in a req, a non deterministic error
                    # occurs when the script attempts to unpack the
                    # build directory

                    # NB: This call can result in the creation of a temporary
                    # build directory
                    location = req_to_install.build_location(
                        self.build_dir,
                    )
                    unpack = True
                    url = None

                    # If a checkout exists, it's unwise to keep going.  version
                    # inconsistencies are logged later, but do not fail the
                    # installation.
                    if os.path.exists(os.path.join(location, 'setup.py')):
                        raise PreviousBuildDirError(
                            "pip can't proceed with requirements '%s' due to a"
                            " pre-existing build directory (%s). This is "
                            "likely due to a previous installation that failed"
                            ". pip is being responsible and not assuming it "
                            "can delete this. Please delete it and try again."
                            % (req_to_install, location)
                        )
                    else:
                        # FIXME: this won't upgrade when there's an existing
                        # package unpacked in `location`
                        if req_to_install.url is None:
                            if not_found:
                                raise not_found
                            url = finder.find_requirement(
                                req_to_install,
                                upgrade=self.upgrade,
                            )
                        else:
                            # FIXME: should req_to_install.url already be a
                            # link?
                            url = Link(req_to_install.url)
                            assert url
                        if url:
                            try:

                                if (
                                    url.filename.endswith(wheel_ext)
                                    and self.wheel_download_dir
                                ):
                                    # when doing 'pip wheel`
                                    download_dir = self.wheel_download_dir
                                    do_download = True
                                else:
                                    download_dir = self.download_dir
                                    do_download = self.is_download
                                unpack_url(
                                    url, location, download_dir,
                                    do_download, session=self.session,
                                )
                            except requests.HTTPError as exc:
                                logger.critical(
                                    'Could not install requirement %s because '
                                    'of error %s',
                                    req_to_install,
                                    exc,
                                )
                                raise InstallationError(
                                    'Could not install requirement %s because '
                                    'of HTTP error %s for URL %s' %
                                    (req_to_install, exc, url)
                                )
                        else:
                            unpack = False
                    if unpack:
                        is_wheel = url and url.filename.endswith(wheel_ext)
                        if self.is_download:
                            req_to_install.source_dir = location
                            if not is_wheel:
                                # FIXME:https://github.com/pypa/pip/issues/1112
                                req_to_install.run_egg_info()
                            if url and url.scheme in vcs.all_schemes:
                                req_to_install.archive(self.download_dir)
                        elif is_wheel:
                            req_to_install.source_dir = location
                            req_to_install.url = url.url
                        else:
                            req_to_install.source_dir = location
                            req_to_install.run_egg_info()
                            req_to_install.assert_source_matches_version()
                        # req_to_install.req is only avail after unpack for URL
                        # pkgs repeat check_if_exists to uninstall-on-upgrade
                        # (#14)
                        if not self.ignore_installed:
                            req_to_install.check_if_exists()
                        if req_to_install.satisfied_by:
                            if self.upgrade or self.ignore_installed:
                                # don't uninstall conflict if user install and
                                # conflict is not user install
                                if not (self.use_user_site
                                        and not dist_in_usersite(
                                            req_to_install.satisfied_by)):
                                    req_to_install.conflicts_with = \
                                        req_to_install.satisfied_by
                                req_to_install.satisfied_by = None
                            else:
                                logger.info(
                                    'Requirement already satisfied (use '
                                    '--upgrade to upgrade): %s',
                                    req_to_install,
                                )
                                install = False

                # ###################### #
                # # parse dependencies # #
                # ###################### #
                if (req_to_install.extras):
                    logger.debug(
                        "Installing extra requirements: %r",
                        ','.join(req_to_install.extras),
                    )

                if is_wheel:
                    dist = list(
                        pkg_resources.find_distributions(location)
                    )[0]
                else:  # sdists
                    if req_to_install.satisfied_by:
                        dist = req_to_install.satisfied_by
                    else:
                        dist = req_to_install.get_dist()
                    # FIXME: shouldn't be globally added:
                    if dist.has_metadata('dependency_links.txt'):
                        finder.add_dependency_links(
                            dist.get_metadata_lines('dependency_links.txt')
                        )

                if not self.ignore_dependencies:
                    for subreq in dist.requires(
                            req_to_install.extras):
                        if self.has_requirement(
                                subreq.project_name):
                            # FIXME: check for conflict
                            continue
                        subreq = InstallRequirement(
                            str(subreq),
                            req_to_install,
                            isolated=self.isolated,
                        )
                        reqs.append(subreq)
                        self.add_requirement(subreq)

                if not self.has_requirement(req_to_install.name):
                    # 'unnamed' requirements will get added here
                    self.add_requirement(req_to_install)

                # cleanup tmp src
                if (self.is_download or
                        req_to_install._temp_build_dir is not None):
                    self.reqs_to_cleanup.append(req_to_install)

                if install:
                    self.successfully_downloaded.append(req_to_install)
def prepare_files(self, finder):
        """
        Prepare process. Create temp directories, download and/or unpack files.
        """
        from pip.index import Link

        unnamed = list(self.unnamed_requirements)
        reqs = list(self.requirements.values())
        while reqs or unnamed:
            if unnamed:
                req_to_install = unnamed.pop(0)
            else:
                req_to_install = reqs.pop(0)
            install = True
            best_installed = False
            not_found = None

            # ############################################# #
            # # Search for archive to fulfill requirement # #
            # ############################################# #

            if not self.ignore_installed and not req_to_install.editable:
                req_to_install.check_if_exists()
                if req_to_install.satisfied_by:
                    if self.upgrade:
                        if not self.force_reinstall and not req_to_install.url:
                            try:
                                url = finder.find_requirement(
                                    req_to_install, self.upgrade)
                            except BestVersionAlreadyInstalled:
                                best_installed = True
                                install = False
                            except DistributionNotFound as exc:
                                not_found = exc
                            else:
                                # Avoid the need to call find_requirement again
                                req_to_install.url = url.url

                        if not best_installed:
                            # don't uninstall conflict if user install and
                            # conflict is not user install
                            if not (self.use_user_site
                                    and not dist_in_usersite(
                                        req_to_install.satisfied_by
                                    )):
                                req_to_install.conflicts_with = \
                                    req_to_install.satisfied_by
                            req_to_install.satisfied_by = None
                    else:
                        install = False
                if req_to_install.satisfied_by:
                    if best_installed:
                        logger.info(
                            'Requirement already up-to-date: %s',
                            req_to_install,
                        )
                    else:
                        logger.info(
                            'Requirement already satisfied (use --upgrade to '
                            'upgrade): %s',
                            req_to_install,
                        )
            if req_to_install.editable:
                logger.info('Obtaining %s', req_to_install)
            elif install:
                if (req_to_install.url
                        and req_to_install.url.lower().startswith('file:')):
                    path = url_to_path(req_to_install.url)
                    logger.info('Processing %s', display_path(path))
                else:
                    logger.info('Collecting %s', req_to_install)

            with indent_log():
                # ################################ #
                # # vcs update or unpack archive # #
                # ################################ #

                is_wheel = False
                if req_to_install.editable:
                    if req_to_install.source_dir is None:
                        location = req_to_install.build_location(self.src_dir)
                        req_to_install.source_dir = location
                    else:
                        location = req_to_install.source_dir
                    if not os.path.exists(self.build_dir):
                        _make_build_dir(self.build_dir)
                    req_to_install.update_editable(not self.is_download)
                    if self.is_download:
                        req_to_install.run_egg_info()
                        req_to_install.archive(self.download_dir)
                    else:
                        req_to_install.run_egg_info()
                elif install:
                    # @@ if filesystem packages are not marked
                    # editable in a req, a non deterministic error
                    # occurs when the script attempts to unpack the
                    # build directory

                    # NB: This call can result in the creation of a temporary
                    # build directory
                    location = req_to_install.build_location(
                        self.build_dir,
                    )
                    unpack = True
                    url = None

                    # If a checkout exists, it's unwise to keep going.  version
                    # inconsistencies are logged later, but do not fail the
                    # installation.
                    if os.path.exists(os.path.join(location, 'setup.py')):
                        raise PreviousBuildDirError(
                            "pip can't proceed with requirements '%s' due to a"
                            " pre-existing build directory (%s). This is "
                            "likely due to a previous installation that failed"
                            ". pip is being responsible and not assuming it "
                            "can delete this. Please delete it and try again."
                            % (req_to_install, location)
                        )
                    else:
                        # FIXME: this won't upgrade when there's an existing
                        # package unpacked in `location`
                        if req_to_install.url is None:
                            if not_found:
                                raise not_found
                            url = finder.find_requirement(
                                req_to_install,
                                upgrade=self.upgrade,
                            )
                        else:
                            # FIXME: should req_to_install.url already be a
                            # link?
                            url = Link(req_to_install.url)
                            assert url
                        if url:
                            try:

                                if (
                                    url.filename.endswith(wheel_ext)
                                    and self.wheel_download_dir
                                ):
                                    # when doing 'pip wheel`
                                    download_dir = self.wheel_download_dir
                                    do_download = True
                                else:
                                    download_dir = self.download_dir
                                    do_download = self.is_download
                                unpack_url(
                                    url, location, download_dir,
                                    do_download, session=self.session,
                                )
                            except requests.HTTPError as exc:
                                logger.critical(
                                    'Could not install requirement %s because '
                                    'of error %s',
                                    req_to_install,
                                    exc,
                                )
                                raise InstallationError(
                                    'Could not install requirement %s because '
                                    'of HTTP error %s for URL %s' %
                                    (req_to_install, exc, url)
                                )
                        else:
                            unpack = False
                    if unpack:
                        is_wheel = url and url.filename.endswith(wheel_ext)
                        if self.is_download:
                            req_to_install.source_dir = location
                            if not is_wheel:
                                # FIXME:https://github.com/pypa/pip/issues/1112
                                req_to_install.run_egg_info()
                            if url and url.scheme in vcs.all_schemes:
                                req_to_install.archive(self.download_dir)
                        elif is_wheel:
                            req_to_install.source_dir = location
                            req_to_install.url = url.url
                        else:
                            req_to_install.source_dir = location
                            req_to_install.run_egg_info()
                            req_to_install.assert_source_matches_version()
                        # req_to_install.req is only avail after unpack for URL
                        # pkgs repeat check_if_exists to uninstall-on-upgrade
                        # (#14)
                        if not self.ignore_installed:
                            req_to_install.check_if_exists()
                        if req_to_install.satisfied_by:
                            if self.upgrade or self.ignore_installed:
                                # don't uninstall conflict if user install and
                                # conflict is not user install
                                if not (self.use_user_site
                                        and not dist_in_usersite(
                                            req_to_install.satisfied_by)):
                                    req_to_install.conflicts_with = \
                                        req_to_install.satisfied_by
                                req_to_install.satisfied_by = None
                            else:
                                logger.info(
                                    'Requirement already satisfied (use '
                                    '--upgrade to upgrade): %s',
                                    req_to_install,
                                )
                                install = False

                # ###################### #
                # # parse dependencies # #
                # ###################### #
                if (req_to_install.extras):
                    logger.debug(
                        "Installing extra requirements: %r",
                        ','.join(req_to_install.extras),
                    )

                if is_wheel:
                    dist = list(
                        pkg_resources.find_distributions(location)
                    )[0]
                else:  # sdists
                    if req_to_install.satisfied_by:
                        dist = req_to_install.satisfied_by
                    else:
                        dist = req_to_install.get_dist()
                    # FIXME: shouldn't be globally added:
                    if dist.has_metadata('dependency_links.txt'):
                        finder.add_dependency_links(
                            dist.get_metadata_lines('dependency_links.txt')
                        )

                if not self.ignore_dependencies:
                    for subreq in dist.requires(
                            req_to_install.extras):
                        if self.has_requirement(
                                subreq.project_name):
                            # FIXME: check for conflict
                            continue
                        subreq = InstallRequirement(
                            str(subreq),
                            req_to_install,
                            isolated=self.isolated,
                        )
                        reqs.append(subreq)
                        self.add_requirement(subreq)

                if not self.has_requirement(req_to_install.name):
                    # 'unnamed' requirements will get added here
                    self.add_requirement(req_to_install)

                # cleanup tmp src
                if (self.is_download or
                        req_to_install._temp_build_dir is not None):
                    self.reqs_to_cleanup.append(req_to_install)

                if install:
                    self.successfully_downloaded.append(req_to_install)
Prepare process. Create temp directories, download and/or unpack files.